Message boards :
Number crunching :
iGPU tuning
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Author | Message |
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HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
Previous in my thread A journey: iGPU slowing CPU processing I had found that using the iGPU on Haswell while also using the CPU slowed CPU processing significantly, around double. A likely culprit of cache thrashing was mentioned. I was considering doing some more testing with the new AP v7 app to see if there was a tuning parameter that might lessen the CPU slowdown. If the slowdown can be brought down to less than (CPU time * 1.5). Then there would be an improved throughput. I am thinking -cpu_lock or -use_sleep might be a good place to start with the HD4600 in my i5-4670K. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
1) cache thrashing, 2) memory bus saturating, 3) automatic frequency adjustement to fit into power budget. Last one can be checked thoroughly by CPU-Z + GPU-Z tools to exclude. |
Mike Send message Joined: 17 Feb 01 Posts: 34258 Credit: 79,922,639 RAC: 80 |
If you have one CPU core freed you could try cpu_lock_fixed_cpu switch. This will bind iGPU to a specific core so shouldn`t interfere with CPU processing. WU : ap_Zblank_9LC67.wu AP6_win_x86_SSE2_OpenCL_ATI_r2346.exe : Elapsed 128.497 secs CPU 35.053 secs AP7_win_x86_SSE2_OpenCL_ATI_r2721.exe -cpu_lock_fixed_cpu 3 -tune 1 64 4 1 -tune 2 64 4 1 : Elapsed 104.739 secs, speedup: 18.49% ratio: 1.23x CPU 6.209 secs, speedup: 82.29% ratio: 5.65x AP7_win_x86_SSE2_OpenCL_ATI_r2721.exe -oclFFT_plan 256 16 256 -cpu_lock_fixed_cpu 3 -tune 1 64 4 1 -tune 2 64 4 1 : Elapsed 88.780 secs, speedup: 30.91% ratio: 1.45x CPU 6.006 secs, speedup: 82.87% ratio: 5.84x Adding oclfft_plan and tune switch should also speed up the iGPU a little. I think its worth a try. It goes without saying that gain on iGPU will be not that big like on discrete GPU. Example -oclFFT_plan 256 16 256 -cpu_lock_fixed_cpu 3 -tune 1 64 4 1 -tune 2 64 4 1 With each crime and every kindness we birth our future. |
Oddbjornik Send message Joined: 15 May 99 Posts: 220 Credit: 349,610,548 RAC: 1,728 |
HAL, I've seen the same slowdown on my 4771K-processor, and I haven't found any solution. You might want to check out my discussion with Raistmer and others in this thread. |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
1) cache thrashing, Are there tools to monitor cache thrashing or memory bus saturation? SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
If you have one CPU core freed you could try cpu_lock_fixed_cpu switch. I plan to start test with running 1 CPU & 1 iGPU task at a time. As previously that still showed double CPU run time. Previously iGPU run times remained constant with MB ~1hr & AP v6 ~3hr if there were 0 CPU or 4 CPU tasks running at the same time. So maybe there is a way to get iGPU to relax some for the sake of the CPU. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
HAL, I've seen the same slowdown on my 4771K-processor, and I haven't found any solution. It may be a design limitation. As the same issue is not present on my BayTrail SOC. I figured that playing around with would app switches couldn't hurt. Maybe there is a happy medium to be found somewhere. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
1) cache thrashing, Yes, but "heavy" ones like Intel's vTune. If you ready to use them you definitely will learn something new regarding your system and other things. But usage learning will required too perhaps. EDIT: maybe some more common tools like Windows embedded perfmon can provide some overview too, BTW. Check perfmon documentation. |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
1) cache thrashing, Intel even offers a trial version so I don't have to put on an eye patch to download it. :) Hopefully the learning curve is not much higher than other system monitoring tools I have used previously at work when breaking software. Having my BayTrail system that doesn't exhibit this slowdown to compare may also prove useful. A fresh OS install on a spare HDD & then making a ghost image of the system before installing tools is probably also in order. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
1) cache thrashing, Yes, you on the right way IMHO :) |
BilBg Send message Joined: 27 May 07 Posts: 3720 Credit: 9,385,827 RAC: 0 |
Are there tools to monitor cache thrashing or memory bus saturation? You may try PerfMonitor http://www.cpuid.com/softwares/perfmonitor2.html http://www.cpuid.com/softwares/perfmonitor.html  - ALF - "Find out what you don't do well ..... then don't do it!" :)  |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
Are there tools to monitor cache thrashing or memory bus saturation? Unfortunately PerfMonitor does not even display the cache info for my BayTrail system. Which I'll be using as a basis of comparison to my Haswell system. It also seems to have an issue showing information sometimes. Much like HWMonitor will sometimes be missing some of the readings until it is restarted a few times. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
I have been playing around with the trial of Intel vTune tool on a system at work. I think I now understand it enough to make send out of things when I start doing testing with the CPU & iGPU apps on my Haswell & BayTrail systems. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
merle van osdol Send message Joined: 23 Oct 02 Posts: 809 Credit: 1,980,117 RAC: 0 |
When I installed my amd cards (2), they told me to first uninstall the igpu before installing. On my bios I can reinstall the igpu or so it looks like. If I do that and it works, how will that affect my gpu crunching and my cpu overclocking. I would like for the igpu to handle all of the daily screen work and have the amd's just working on wu's, but I don't want to see any downgrade in the gpu's or the cpu's. Will that work do you think? Thanks. merle - vote yes for freedom of speech |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
When I installed my amd cards (2), they told me to first uninstall the igpu before installing. On my bios I can reinstall the igpu or so it looks like. If I do that and it works, how will that affect my gpu crunching and my cpu overclocking. I would like for the igpu to handle all of the daily screen work and have the amd's just working on wu's, but I don't want to see any downgrade in the gpu's or the cpu's. Will that work do you think? Thanks. I still have no idea why you would be told to disable the iGPU & I have not seen any documentation about doing that before. Using the iGPU for your general display shouldn't be an issue for CPU & the add-in GPU's processing. I have the iGPU enabled on my systems & only see slowdown issues while using the iGPU to process work. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
merle van osdol Send message Joined: 23 Oct 02 Posts: 809 Credit: 1,980,117 RAC: 0 |
When I installed my amd cards (2), they told me to first uninstall the igpu before installing. On my bios I can reinstall the igpu or so it looks like. If I do that and it works, how will that affect my gpu crunching and my cpu overclocking. I would like for the igpu to handle all of the daily screen work and have the amd's just working on wu's, but I don't want to see any downgrade in the gpu's or the cpu's. Will that work do you think? Thanks. I got my iGPU reinstalled and reset in the bios. Perhaps the screens are a bit faster but that is about all. I did have some unused capacity in my gpu's in any event. If I had to, I could send you a copy of the amd quick guide to install my 280x. There must be others out there who have gone thru the same thing. Unless they just sent me the wrong quick guide for the 280x.Just reinstall from intel or Microsoft and reset your bios. No problems. merle - vote yes for freedom of speech |
Wiggo Send message Joined: 24 Jan 00 Posts: 34748 Credit: 261,360,520 RAC: 489 |
Installing those drivers supplied by Microsoft can lead to very bad problems, don't use them, just use drivers supplied by the manufacturer. ;-) Cheers. |
merle van osdol Send message Joined: 23 Oct 02 Posts: 809 Credit: 1,980,117 RAC: 0 |
I reinstalled the driver from intell to make sure it was the right one. All my indicators tell me that it is the intell 4600 driver and it's hooked up ok but for some reason I get no power to it. It sits there like its dead. Should I hook up a dummy plug or something? --edit I just plugged in my intel graphic card socket with the monitor which I had in the first gpu card and it worked. merle - vote yes for freedom of speech |
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