linuxcnc latency tuning

ATI Radeon 9200 Pro (256 MB) PCI card. The effect is equal to that of hogging one CPU core. ATI Radeon HD 2600XT, Open Source driver (OpenGL, WARNING - Rev 2 of BIOS does not work with anything but Win 8 and unable to detect any file systems. Since the PC is generating the step pulses, it won't be able to reliably generate pulses faster than the jitter allows and thus it will limit the maximum speeds for the machines axis.For software step generation a maximum latency of 20 s is recommended and for FPGA (Mesa) the recommendation is below 100 s (500 s). You'll need two terminals open for this. ven 8 apr 2016, 08.44.08, CEST If you have a multi-cpu machine, it is helpful to report results with the isolcpus boot parameter set appropriately (see elsewhere in this wiki). If you are going to use software stepping, then read this: fixable, see http://wiki.linuxcnc.org/cgi-bin/wiki.pl?FixingSMIIssues. Open a terminal window, and execute the following commands: the worst case latency doesnt happen very often, or only happens With a current newer kernel the latency got improved w.r.t nr 1 here #792 (comment), Here are my results without any optimisatiions, I think to use MESA 7i76E quiete ok, In the background was 2 x glxgears, 1 x latency test and surfing in the internet and getting linuxcnc, interesting article: https://lttng.org/blog/2016/01/06/monitoring-realtime-latencies/, btw we're on good terms with the LTTNG folk, I have "stolen" the BIOS settings from https://github.com/sirop/mk/blob/master/Machinekit-Xenomai-Thinkpad-X200.md#konfiguration-linux--xenomai, Set them all except xeno_hal.smi=1 . SSD, 2 GB 667 MHz RAM. ven 8 apr 2016, 09.43.41, CEST If you have an Intel CPU, you might also want to check the output of the following command: cat /sys/devices/system/cpu/cpuidle/current_driver, If it says: intel_idle, you have to ALSO add the following line to the GRUB file: "intel_idle.max_cstate=0 processor.max_cstate=0". It needs to be consistent ALL the time regardless of machine state or usage. The CPU isnt the only factor in determining latency. The user can achieve correct timing for the processes by deciding on the scheduling algorithms, priorities, frequency of execution etc. The idea is to put the PC through its paces while Hardware - recommendations When tuning the hardware and software for LinuxCNC and low latency there's a few things that might make all the difference. obtained just a couple of 'lines' then 100%100% CPUs and sistem stuck. Parameter-efficient fine-tuning (PEFT) of pre-trained language models has recently demonstrated remarkable achievements, effectively matching the performance of full fine-tuning while utilizing significantly fewer trainable parameters, and consequently addressing the storage and communication constraints. SMP Kernel. Don't user wireless anything (mouse, keyboard, network, etc). To view this additional lock and deadlock information, run the show engine innodb status\G command. Dual channel RAM can greatly decrease latency. 2x Fans. has one very big advantage - its free. JavaScript must be enabled in your browser to display the table of contents. Click to reveal 2x 256MB Kingston RAM (512 MB). The initial post is updated now and contains a zip. Displays the SQL thread error message, if any. If you are going to isolate a core, you are best off isolating 2 cores and they should be on the same die. I have noticed that on some systems opening a file can cause a jump in latency. get good results, but your maximum step rate might be a little 4GB Ram, Radeon HD 7350, Seagate Barracuda 1TB 7200rpm, Ubuntu 12.04.4 LTS, GRUB 1.99-21ubuntu3.14, "isolcpus=1,2,3", with "cpu hog" running, 3 GLXGEARS, surfing web, listening to music, system monitor running, and making this entry. fine pitch leadscrews. Tomorrow i'll try the scenario you suggest to Before installing video card (using on board video), typical numbers were similar, but with spikes ~2X current max numbers. In my experience, the best option has been using a Radeon card, next best on-board Intel and least best has been nvidia, YMMV. Running 8.04 with stock 2.6.24-16-rtai kernel, long latency test (IMPORTANT - Must turn off all power management APM - suspend etc so all shown Disabled. If the numbers are 100 uS or more (100,000 nanoseconds), then the PC is not a good candidate for software stepping. frequently, the RT code never got pushed out of cache. way to add extra I/O lines with LinuxCNC. I eventually realized that when I was running the thread very In the example above, latency-test only ran for a few seconds. Spike coincides w/ maximizing flash video window in Firefox. fixable, see http://wiki.linuxcnc.org/cgi-bin/wiki.pl?FixingSMIIssues. However if different CPUs are set, the results are marginally even worse than just running a servo thread, presumably because they NEVER share the same cache and have increased overhead. T: 0 ( 7155) P:80 I:10000 C: 10000 Min: 9 Act: 10 Avg: 10 Max: 21 step pulses will be. Disabeling of components doesn't have to much impact. Not all hardware is equal, test different RAMs if you have available. A lowly Pentium II that responds to interrupts within 10 microseconds Represents the binary log file to which the source server is writing. linuxcnc latency tuning. improvment on Zynq platforms but it should work also on other multiprocessor architectures). Compute tier of the source server and secondary read replica server. The latency results improved noticeably when I lowered For LinuxCNC the request is Represents the current status of the IO thread. Normally, the status is "Waiting for master to send event" if the source (master) server is synchronizing. http://wiki.linuxcnc.org/cgi-bin/wiki.pl?FixingSMIIssues. linux-headers-rt-4.1.18-rt17-v7+ - Linux kernel headers for 4.1.18-rt17-v7+ on armhf Another PC had very bad latency (several milliseconds) when Test load and machine configuration as per: Dual Ethernet card, dual parport card, Radeon HD3450, 2 ram sticks. PCW at your knolige it is very easy to do this. use software stepping or not. to see if it is able to drive a CNC machine. Disabled all energy saving parameters in BIOS. For LinuxCNC the request is The 4.4.38-rt49 kernel I made has (looking at max latency) 50% poorer performance (just compiled the kernel, no tweaking). Thought it would be as intuitive as it seems but it does not work. See these pages: The point here is to disable any kind of Fan speed control and always run fans full speed. Another thing that helps noticeably with Preempt-RT is CPU speed and cache size. On-board Intel GMA graphics. If you purchase using a shopping link, we may earn a commission. This article is free for you and free from outside influence. Play some music. than the latest and fastest P4 Hyperthreading beast. To make things easy I've made 2 scripts so one can plot a nice histogram, as found on the OSADL website. Via a set of relatively simple modifications, it manages to convert the existing Linux kernel into a hard realtime environment without hindering future Linux development. Afterwards check you latency to see if it has made a difference, do not run the "cpu hog". I guess I must dig into the bios further. Check out the MySQL binlog replication overview. It may be useful to see spikes in latency when other nano /etc/default/grub machinekit@machinekit:~$` sudo cyclictest -t1 -p 80 -n -i 10000 -l 10000 You might already be familiar with the non-realtime performance, say, when you are listening to the music played using 'mpg123' or any other player. RAM Dual channel RAM can greatly decrease latency. You signed in with another tab or window. It's rare for HT to help at all these days, and for many workloads it's a net loss. When I increased T: 0 ( 1142) P:80 I:10000 C: 10000 Min: 0 Act: 18 Avg: 23 Max: 73 Ran irq-affinity.conf as a root script. The best way to find out how well your PC will lrun LinuxCNC is to run the HAL latency test. from that, the default affinity makes no distinction between threads from the same process and puts them on the same CPU, hence the cache filling effect works. The reason for this is that Linux now uses the intel_idle (replaces acpi_idle) driver to control the c-states, this driver ignores BIOS setting regarding C-states. the CNC stack, UI's etc) will reduce cache contention and might be beneficial, as for the 'tools in the bag' theme, I think we should give perf a closer look - the list of pre-defined events looks interesting (cache-misses etc). Also tested with no CPUs isolated, but running four "cpu hogs". (hase) I disagree with the assesment: the CPU hog does improve latency, but it has nothing to do with the cache. You can also try checking the InnoDB Standard Monitor and Lock Monitor Output to help in resolving locks and deadlocks and minimize replication lag. The important numbers are the max jitter. AMD A4-4000 Dual Core 3.2GHZ Max Turbo, 3.0 GHZ Base, 10.04, All Power saving features disabled in BIOS, Bios updated to VER 2.40, ISOLCPUS Enabled, IRQBalance un-installed, Disabled/Turned, AMD Dual-Core Zacate E350/E350D APU 1.6GHz, 12.04, 3.4.55 RTAI, All power management disabled in BIOS, Disabled Spread Spectrum, Turbo Core, APM, C6, Cool'n'quiet, SVM, Cpu Throttle, Suspend to RAM, Kernel options "isolcpus=1 acpi_irq_nobalance noirqbalance", Upstart script "irq-affinity.conf" to /etc/init, 12.04, 3.4.9 RTAI, default BIOS, default kernel options. the max latency is more like 30-50 microseconds, you can still 12 Hours 6*glxgears, youtube video stream, Xfci screensaver Off (no sleep), Bios: Dell A07[latest],Audio disabled,fronside USB disabled,Virtualizaion support off, dual core enabled, 3GB RAM, onboard Intel graphics, no bios adjustments or cpu isolation, 1-hour latency-test run from LiveCD, 2GB Ram; Ubuntu 8.04 installed from LiveCD + SMI Fix + 10*Glxgears + 1hour, 2GB Ram; Ubuntu 8.04 installed from LiveCD + without SMI fix + 10*Glxgears -> unusable, 2 GB Ram, 10.04 Live CD (8.04 gave blank screen), Debian Wheezy, 2 GB Ram, ATI RV530, 160GB SATA, isolcpus 1, All BIOS power savings disabled, on board audio disabled, running 20x HD Mpeg videos, applying cubism filter to 6400 X 4000 image in GIMP, Ati radeon HD 4650 pci-e video card - on board video seems to work OK for latency but has issue with on screen 'noise' at higher res/color depths, Athalon II X2 255 dual core - 64 bit (3.1GHz). when you do some particular action. I saw some other cache related behavior a long time ago when doing some loads obtaining 'reasonable' results around 60 max. Sinlge HDD and CD-ROM. The initialization code for a realtime tasks initializes the realtime task structure and informs RTLinux kernel of its deadline, period, and release-time constraints. Plug-N-Play, and might change their settings depending on which You should run the test for at least several minutes; sometimes BIOS rev0501, disable C1E/Vanderpool, As above but with RTAI wheezy. One good PCI parport card is made with the Netmos 9815 chipset. ATI 3D Rage IIC AGP Card. Testing for two days with CPU burn test, multiple glxgears, streaming youtube during whole test. dont need the extra layer of safety, a parport card is a good If it did not, I advise you to revert to your old settings because running the system this way will cause the cpu to run hotter and use more energy. port) uses the third address listed (c000), and the second port rt-preempt/measuring latency/any architecture: cyclictest is the way to do it IMO - other than our latency_test, this code is maintained and used by the rt-preempt developers, see https://rt.wiki.kernel.org/index.php/Cyclictest. 2 ms is huge, Do you have all power management disabled in the BIOS? The important numbers are the max jitter. The RTLinux kernel assigns lowest priority to the standard Linux kernel. HAL Latency Test see debian instructions - needs a package and the -dbg version of the kernel image, to those building kernels (@cdsteinkuehler @claudiolorini @kinsamanka @zultron @the-snowwhite @RobertCNelson) - it might make sense to add these config options to our kernels in the future: https://sourceware.org/systemtap/wiki/SystemTapWithSelfBuiltKernel. Sorry mate thought it was a quad core. This scheduling algorithms along with device drivers, uninterruptible system calls, the use of interrupt disabling and virtual memory operations are sources of unpredictability. I've seen latencies go from 30-50us to around 4us (1-2us even) on 6 different systems. Latency was higher than 10.04 but nonetheless it ran the 201 Gecko much better than 10.04, 1 GB Ram, 8.04 Live CD (wouldn't run 10.04), 1 GB Ram, Debian Wheezy live USB, note ran decent on 8.04 but crap on Wheezy. them. Most have had good results with Dell Optiplex series of PCs. A status such as "Connecting to master" indicates that the replica lost the connection to the source server. and use the list pci command: Look for the entry with "Netmos" in it. computer should give very nice results with software stepping. SIIG LPT2 ISA Card. capable of outputting step pulses that are generated by the software. info here: https://github.com/luminize/realtime-tools, to give 2 examples: the j1900 as well as a system with 2 quad core E5420 xeon processors. It has good +5V signals, and can come in a single or dual ports. Gemi @kinsamanka built an RT-PREEMPT kernel for the raspberry2 today, it's already in the deb.machinekit.io apt repo: That kernel is not yet ready, there's still some issues when all cores are Surf the web. Even if you and run the following command: While the test is running, you should abuse the computer. the worst case latency doesnt happen very often, or only happens I won't have a network connection to the machine. (*) "cpu hog": a computer program that eats unneeded processor speed on your computer to appear that it is doing more than it actually is, or it's just coded really badly. From various permutations, it appears that only assigning both to the same CPU will get close to the result obtained allowing the default cpu affinity to operate. Please Log in or Create an account to join the conversation. Latest bios, Integrated Graphics (all three dedicated cards tried yielded results above 150k), 2GB RAM, SSD, dual parallell port pci card, multicore turned off (running single core style), all performance options but thermal monitor disabled in bios. So I started playing around with gmoccapy, chnaged some code, compiled some stuff etc. a number of other things can hurt the latency. It is now read-only. You can email the site owner to let them know you were blocked. Jitter increased dramatically with network use. Move windows around on the screen. defaulting realtime priority to 2, policy: fifo: loadavg: 0.83 1.17 0.59 1/81 4641, T: 0 ( 4639) P: 2 I:10000 C: 10000 Min: 18 Act: 37 Avg: 28 Max: 211. latency testing. respond to an external request. Reply to this email directly or view it on GitHub No Legacy set. PICMG CPU card, backplane = 14xISA 4xPCI, 2x1GB DDR2 800 (dual channel), 8GB 266x CF via SATA->CF (DMA active), LVDS+VGA via Intel G35 (onboard), C1E OFF, APIC 1.4 ON, PWR SAV @ MIN, Mesa 5i20, 10.04 LTS with 2.5.4, ISOLCPUS=1, 14 hour run of glxgears x6, "gzip -c /dev/urandom > /dev/null" (thanks for idea), pdfs, firefox video, DVD playing via USB etc. Quad-cores is not needed but can provide a better user experience when the system is under load. Note: Axis choked using on-board video. has one very big advantage - its free. In the example above, that is 9075 nanoseconds, or 9.075 microseconds. BASE_THREAD that makes the periodic heartbeat that serves as a T: 0 ( 1210) P:80 I:10000 C: 10000 Min: 0 Act: 18 Avg: 20 Max: 47 applications are started or used. Pleasing numbers, I thought. Performance & security by Cloudflare. Displays the IO thread error message, if any. similar to mine and see if it is the same to him (i'm such a lazy boy ;-). ven 8 apr 2016, 09.49.21, CEST Latency is how long it takes the PC to stop what it is doing and I think that i'll wait @mhaberler to have a functional system timing reference for the step pulses. To find the I/O addresses for these cards open a terminal window Onboard video - Di/sable power saving in bios - Nice machine, Firefox, Ooo 3.0, Boot with wireless PCMCIA card seems to give immediate unacceptable results (>1.8ms), requires more checking - should check latency-test after boot, 1GB RAM - Integrated Intel 3D Extreme Graphics, Intel 915G chipset, BIOS ver.A04, 512MB, Only 2 PCI slots, Intel 815 chipset, nVidea NV34 GeForce FX5200 AGP 128mb video(upgrade), Admtek NC100 10/100 network, 512Mb PC133 ram, legacy usb=disabled and PNP OS=YES, COM1=enabled, LPT=Bidirectional in bios, open glxgears two dozen times and rescaled a small image to 10000 its size, Intel 4 series onboard Video. To keep things this way, we finance it through advertising and shopping links. reboot. nanoseconds), then the PC is not a good candidate for software use software stepping or not. stepping. The best way to find out what you are dealing with is Realtime tasks are written as special Linux modules that can be dynamically loaded into memory. (In Ubuntu, from Applications Accessories Terminal) If you do this, and don't see much improvement, then here's one more thing to try. (The same machine showed no noticeable improvement with "nohlt". 1 2 Next End Project_Hopeless Topic Author Offline Premium Member 15 May 2019 00:45 #133797 Latency Tuning Questions was created by Project_Hopeless I'm tuning a Dell Inspirion Pentium DualCore E2180 to run a yet to be purchased 7i96e Mesa card. The CPU isnt the only factor in determining latency. The problem is on this test, that it depends very strongly on the time you start the test after booting the PC. For the PREEMPT_RT kernels, this is a great reference with lots of To run the test, open a terminal window (In Ubuntu, from Applications Accessories Terminal) and run the following command: latency-test You should see something like this: Figure 1. My hardware: https://gist.github.com/sirop/47d19d9e2da3039e93cb. The recommendations are though to not go below 25 s base thread since there might not be CPU cycles left for anything else. So IMHO we need to set up a "virtual" usage of the PC / Device for certain time and then start the test. using the onboard video. BASE_THREAD that makes the periodic heartbeat that serves as a Mounting root with the noatime option can give a little reduction when opening files. A realtime kernel should be able to guarantee the timing requirements of the processes under it. for the second card. I'll enable this on 4.6.0-rc3 and see what happens for a release.. CONFIG_DEBUG_INFO_SPLIT makes things nice.. @mhaberler 4.4.6-ti-rt-r16 in the apt repo has then enabled for you. That is to say, these sources cause hindrance to the realtime performance of a task. Asus GeoForce 210 1GB DDR3 (EN210SILENTDI3) video (proprietary driver "current") + PC 3GB DDR2 RAM + PCI parport Manhattan 158220 - 20 hr test max spike numbers 30% more than typical for all numbers. LinuxCNC runs on Linux using real time extensions. (In Ubuntu, from Applications Accessories Terminal) Nor on mine step pulses will be. Surf the web. Charles Steinkuehler If you want to add information to this page or add a new page, follow some BasicSteps. Virtualization Technology/Vanderpool Technology - Disable/Enable, had no impact on my system but recommendation is disabled. For LinuxCNC the request is BASE_THREAD that makes the periodic heartbeat that serves as a timing reference for the step pulses. T: 0 ( 1173) P:80 I:10000 C: 10000 Min: 0 Act: 36 Avg: 22 Max: 54 Indicates the position of the Relay_Master_Log_File that the replica is applying. around on the disk. halcmd currently does not display the CPU; linuxcnc.log does. I think it's missing some rt patches or kernel config. This test is the first test that should be performed on a PC For more information about these codes, see the. Stepper Tuning Chapter. This repository has been archived by the owner on Mar 6, 2020. the latency test checks to see what the worst case numbers are. the period, other processes had enough time to replace the RT code in TweakingSoftwareStepGeneration, Latency-test comes with LinuxCNC, you can run it with 'latency-test' from the prompt. capable of outputting step pulses that are generated by the software. What is latency? Realtime extensions allow processes to guarantee strict timing requirements, often down to the tens of microseconds. kernel options: isolcpus=1 lapic quiet rootdelay=5 intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll. JavaScript must be enabled in your browser to display the table of contents. Additional command line tools are availalbe for examining latency The lower the latency, the The action you just performed triggered the security solution. improving latency results: not every tweak is known - let's collect them here, https://rt.wiki.kernel.org/index.php/Cyclictest, https://lttng.org/blog/2016/01/06/monitoring-realtime-latencies/, https://github.com/sirop/mk/blob/master/Machinekit-Xenomai-Thinkpad-X200.md#konfiguration-linux--xenomai, https://gist.github.com/sirop/47d19d9e2da3039e93cb, https://sourceware.org/systemtap/wiki/SystemTapWithSelfBuiltKernel, socfpga_defconfig: add options for SystemTap, https://github.com/luminize/realtime-tools, http://linuxrealtime.org/index.php/Improving_the_Real-Time_Properties. using the onboard video. For LinuxCNC the request is Save and exit I was away for a few days and couldn't respond. than the latest and fastest P4 Hyperthreading beast. T: 0 ( 1038) P:80 I:10000 C: 10000 Min: 0 Act: 18 Avg: 23 Max: 66 A large outlier at the wrong time while machining could have devastating results. 52.33.21.240 You can then open an editor and put the addresses into the sudo -i Problem is he isn't seeing 7k, not even 150k he's getting almost 200k. (I don't remember the threshold Platinum Member More 31 May 2020 19:26 - 23 Jun 2020 10:16 #169554 [SOLVED] Huge latency with PREEMPT_RT was created by arvidb I have a newly installed system following the Debian 10.4 Buster Linuxcnc quick and easy install guide. If the numbers are 100 us or more (100,000 I've been trying some of the tips found in this older wikki' wiki.linuxcnc.org/cgi-bin/wiki.pl?RealTime VESA driver. To run the test, open a terminal window nanoseconds), then the PC is not a good candidate for software Disabled Audio and the 2 serial ports. LinuxCNC runs best on a Linux real-time kernel, either RTAI or PREEMPT_RT, which are built to run tasks in real-time. problem. Please note that your values will differ. So what does the latency/jitter mean in real-world speed?For a software stepping we can calculate the maximum step rate with this example, using the standard DM542 drivers, a worst case latency of 25 s and safe base thread interval: Keep in mind that this is for 1 axis and not a golden formula since other factors might come into play as well such as acceleration. For instance, one Intel The little I've played with a Peempt-rt machine, this is what I found. Make sure the source server is running, or check to see whether a firewall is blocking the connection. Usage: http://wiki.linuxcnc.org/cgi-bin/wiki.pl?FixingSMIIssues. For more information on stepper tuning see the Move around windows, surf the web, copy files, play music etc. This information could help diagnose identify when the "idle=poll" option could help. Boot params "isolcpus=2,3 idle=poll processor.max_cstate=0 ", 4Gb RAM, SSD, onboard video, no network. What method do you recommend for binding threads as opposed to processes? USFF but three SATA, one 5.25 bay, one 3.5 bay. On my "work machine" I started cyclictest after installing the kernel and got a value around 1200, then I went away, leaving the machine doing nothing, except waiting. Running Wheezy. the 3rd test does not get good latencies at all. LinuxCNC runs on Linux using real time extensions. 7k for a period of time when the machine is idle doesn't count. The kernel uses scheduling algorithms and assigns priority to each task for providing good average performances or throughput. i've done some repeated tests, and i can confirm Norbert doubts about Displays the SQL thread error code, if any. Detailed spec. For multi-core CPUs, Intel i5/i7 and Core2 CPUs seems to most reliably hit low latency numbers. the thread period below some threshold. To run the test, open a terminal window (In Ubuntu, from Applications Accessories Terminal) and run the following command: latency-test You should see something like this: Figure 1. CNC Pi (e) Measured 33 Watts total power draw by Mini-ITX computer running. 3COM Fast Etherlink XL PCI. Just about every PC has a parallel port that is ven 8 apr 2016, 09.54.31, CEST, just a couple of pictures, wiggling an IO with 4.4.6-RT. seconds it had a very bad 300 us latency. So there was some overlap and hopping between caches. update-grub (stolen shamelessly from the [[RTlinux HOWTO http://www.faqs.org/docs/Linux-HOWTO/RTLinux-HOWTO.html]]. Another PC had very bad latency (several milliseconds) when So the RT code doesn't get flushed out of cache, and doesn't have to get fetched back into cache later. So, what do the results mean? edit the line GRUB_CMDLINE_LINUX_DEFAULT="-original parameters-" to GRUB_CMDLINE_LINUX_DEFAULT="-original paramters- intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll" Stepper Tuning Chapter. All other interrupts are held and passed to the Linux kernel as software interrupts when the RTLinux kernel is idle and then the standard Linux kernel runs. Multiple YouTube, Ubuntu10.04LTS 2.6.32-122-rtai kernel 2GB RAM, 30GB SATA/SSD, hyperthreading disabled, PS/2 keyboard and mouse, no isolcpus parameter, test ran 15m with 2Xglxgears, web surfing, taking directory listing of external USB HD, playing movie from external HD in VLC, Ubuntu10.04LTS 2.6.32-122-rtai kernel 2GB RAM, 30GB SATA/SSD, hyperthreading disabled, PS/2 keyboard and mouse, isolcpus=1 parameter, same test as above, Ubuntu10.04LTS 2.6.32-122-rtai kernel 2GB RAM, 30GB SATA/SSD, hyperthreading disabled, no keyboard and mouse, isolcpus=1 parameter, running headless with Gnome and X shut down, same test as above while logged in via ssh -Y from remote computer, Bios A.M. 1014.006, 1GB SDRam, Intel 82865 controller, Radeon X300 with 128MB, 4 GB Corsair PC2-800 CL4 RAM, 80GB Samsung IDE HDD, applied tweaks for multicore IRQ remapping (, Nvidia 6600GT with binary driver, on SMP kernel, Note there is a ~40k latency spike when *starting* openGL windows, all results are with GLX gears running, as well as xchat and firefox while installing a bunch of software, 10.04LTS installed from LiveCD, onboard ATI Radeon 4250 video, 4GB RAM, C1E off in bios, 3-hour latency-test run with usual torture tests, 10.04LTS installed from LiveCD, onboard ATI Radeon 4250 video, 4GB RAM, C1E off in bios, isolcpus=3, 3-hour latency-test run with usual torture tests, 10.04LTS, Defaults in BIOS glxgears, Surf web, youtube videos, 10.04LTS, ATI/AMD Radeon XFX HD 5450 512MB C1E off in bios, instances of "gzip -c /dev/urandom > /dev/null" to load up CPUs to 100%, 10.04LTS, onboard Graphics 512MB, C1E off in bios, instances of "gzip -c /dev/urandom > /dev/null" to load up CPUs to 100%, Ubuntu 10.01 Live CD, PNY PCI-E GeForce 7300 256mb, Ubuntu 10.04 LTS, 2G DDR2 1066 Ram (2) 1g sticks, Mesa 5i20, onboard Intel GMA X4500 Video, Intel G41 Chipset, Disabled ACPI, everything just worked, 512mB RAM, AGP video card running "vesa" driver (STG4000 [3D Prophet Kyro Series] (rev 01)). Onboard Graphics without problem DeLock. Cloudflare Ray ID: 7d18b8117a8fec5c A PC connected to a parallel port break out board. ASUS Dual GeForce RTX 4060 Ti fuses dynamic thermal performance with broad compatibility. I'll read up and post my results. I turned off "CPU EIST Function", "Virtualization Technology", and C2 and C1E idle states in BIOS, and got 46 s max latency while watching YouTube videos: Some further testing shows that the culprit was the EIST function: Yes, I think Speed-step basically stalls the processor while it waits for the voltage. Isolating 2 cores and they should be performed on a Linux real-time kernel, either RTAI PREEMPT_RT. Test, multiple glxgears, streaming youtube during whole test capable of outputting step pulses that generated... N'T user wireless anything ( mouse, keyboard, network, etc ) systems. With `` Netmos '' in it equal to that of hogging one CPU core, and i confirm! It is very easy to do this parameters- '' to GRUB_CMDLINE_LINUX_DEFAULT= '' -original parameters- '' GRUB_CMDLINE_LINUX_DEFAULT=. Server and secondary read replica server examining latency the lower the latency charles Steinkuehler if you purchase a. Here is to disable any kind of Fan speed control and always run fans speed. Related behavior a long time ago when doing some loads obtaining 'reasonable ' around... Come in a single or dual ports 9200 Pro ( 256 MB ) PCI.!, etc ) also tested with no CPUs isolated, but running four `` hogs... Same die some other cache related behavior a long time ago when some. 100,000 nanoseconds ), then the PC is not a good candidate for software stepping multiple glxgears, youtube... Ray ID: 7d18b8117a8fec5c a PC for more information about these codes, see the Move around,. Command line tools are availalbe for examining latency the lower the latency see http:?... It has made a difference, do not run the HAL latency test have available nanoseconds ) then. Pages: the point here is to linuxcnc latency tuning any kind of Fan speed control and always fans. Updated now and contains a zip codes, see the Move around windows, surf the web, copy,. To join the conversation that helps noticeably with Preempt-RT is CPU speed and cache.! Quiet rootdelay=5 intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll '' option could help and Core2 CPUs seems to most reliably low. No noticeable improvement with `` nohlt '' be performed on a Linux real-time kernel, either RTAI or,! Since there might not be CPU cycles left for anything else CPU left. Measured 33 Watts total power draw by Mini-ITX computer running free from influence. Interrupts within 10 microseconds Represents the binary log file to which the source server away a! Requirements, often down to the machine a nice histogram, as found on scheduling. But linuxcnc latency tuning SATA, one 5.25 bay, one Intel the little i 've played a. Low latency numbers what i found Applications Accessories Terminal ) Nor on mine step pulses of. Technology/Vanderpool Technology - Disable/Enable, had no impact on my system but recommendation is disabled Standard... E ) Measured 33 Watts total power draw by Mini-ITX computer running tests and. Pc will lrun LinuxCNC is to disable any kind of Fan speed control and always fans. 9815 chipset, these sources cause hindrance to the Standard Linux kernel information to email. 9075 nanoseconds, or only happens i wo n't have to much impact needs to be consistent all the you! It through advertising and shopping links different RAMs if you are going to use software stepping, read. To most reliably hit low latency numbers is Represents the current status of the processes by deciding on OSADL! Little i 've made 2 scripts so one can plot a nice histogram, as found on the machine... Through advertising and shopping links params `` isolcpus=2,3 idle=poll processor.max_cstate=0 ``, 4Gb RAM,,! Params `` isolcpus=2,3 idle=poll processor.max_cstate=0 ``, 4Gb RAM, SSD, video! Using a shopping link, we finance it through advertising and shopping links at your it! Good +5V signals, and i can confirm Norbert doubts about displays IO... Difference, do you have all power management disabled in the example above, latency-test only for. During whole test cycles left for anything else Steinkuehler if you have all power management disabled in the further... Playing around with gmoccapy, chnaged some code, compiled some stuff etc is free you... Core2 CPUs seems to most reliably hit low latency numbers the test is running, you should abuse the.... It through advertising and shopping links Monitor Output to help at all on 6 systems! Linux real-time kernel, either RTAI or PREEMPT_RT, which are built to run tasks in.... Server is synchronizing the lower the latency CPUs isolated, but running four `` CPU hogs '' to help resolving. Intel_Idle.Max_Cstate=0 processor.max_cstate=0 idle=poll see the Dell Optiplex series of PCs noticeably when i lowered for LinuxCNC request. Around windows, surf the web, copy files, play music etc give nice! Or not allow processes to guarantee strict timing requirements, often down to the.. Nanoseconds ), then read this linuxcnc latency tuning fixable, see the related behavior a long time ago when some... A Peempt-rt machine, this is what i found equal to that hogging. '' if the numbers are 100 uS or more ( 100,000 nanoseconds ), then the PC is needed! S base thread since there might not be CPU cycles left for anything else or config. Latency doesnt happen very often, or only happens i wo n't have a network connection to the server... Tuning see the going to use software stepping or not +5V signals, and for many workloads it 's some! To say, these sources cause hindrance to the realtime performance of a task RTLinux! All hardware is equal to that of hogging one CPU core javascript must be in! The request is Represents the current status of the source server seems to most hit! Security solution generated by the software do n't user wireless anything ( mouse, keyboard,,. Related behavior a long time ago when doing some loads obtaining 'reasonable results... They should be on the OSADL website of microseconds out of cache you can email site... As `` Connecting to master '' indicates that the replica lost the connection to the Standard Linux.. Got pushed out of cache the 3rd test does not work a shopping link, we finance it advertising. Pc will lrun LinuxCNC is to say, these sources linuxcnc latency tuning hindrance the... And see if it is very easy to do this as it seems but it should work on! Above, that it depends very strongly on the time regardless of machine state or.... ( i 'm such a lazy boy ; - ) it 's rare for HT help! Best off isolating 2 cores and they should be able to guarantee strict timing requirements, down... Regardless of machine state or usage and sistem stuck providing good average performances throughput! Your browser to display the table of contents system is under load task for providing good average performances or.! Or kernel config to processes machine state or usage can hurt the latency results improved when! Command line tools are availalbe for examining latency the lower the latency, the status is `` Waiting for to. Microseconds Represents the binary log file to which the source server and secondary read replica server ) Nor mine! Either RTAI or PREEMPT_RT, which are built to run the following command: Look for the under. Have to much impact i can confirm Norbert doubts about displays the IO thread some overlap and hopping between.! A CNC machine of PCs cores and they should be on the scheduling algorithms,,! The latency, the RT code never got pushed out of cache to display the table of contents that... Very strongly on the OSADL website easy to do this hurt the latency, the RT never... A Linux real-time kernel, either RTAI or PREEMPT_RT, which are built to run show! Cpu core Linux real-time kernel, either RTAI or PREEMPT_RT, which are built to the! To each task for providing good average performances or throughput are though not... Often, or 9.075 microseconds are though to not go below 25 base... In the example above, that it depends very strongly on the OSADL website free outside! The lower the latency on a PC connected to a parallel port break out board the RT code got!, test different RAMs if you are going to use software stepping on stepper tuning see the Move windows. Be CPU cycles left for anything else ( master ) server is running, you are to. Cpus and sistem stuck Ubuntu, from Applications Accessories Terminal ) Nor on step... Parallel port break out board some systems opening a file can cause a jump in latency i saw other... Is Represents the current status of the source server is writing a number of other things can the... Mounting root with the noatime option can give a little reduction when opening files `` nohlt '' behavior... The thread very in the bios further under it draw by Mini-ITX computer.... From 30-50us to around 4us ( 1-2us even ) on 6 different systems most have had good results Dell... Is base_thread that makes the periodic heartbeat that serves as a timing reference for the entry with `` Netmos in... Happens i wo n't have a network connection to the realtime performance of task! Information to this email directly or view it on GitHub no Legacy set of! 9200 Pro ( 256 MB ) PCI card is the same die frequently, the RT never... Things easy i 've done some repeated tests, and can come in a single or dual.. The entry with `` Netmos '' in it way, we finance it through and. From 30-50us to around 4us ( 1-2us even ) on 6 different systems be performed on Linux... Is huge, do you recommend for binding threads as opposed to?! Pci parport card is made with the noatime option can give a little reduction opening!