2019/07/21 15:01:32
jasoncodispoti
bcavnaugh
 
Prime95 is not using AVX-512 unless you tell it to.
Prime95 29.5 now supports AVX-512
https://linustechtips.com/main/topic/985047-prime95-295-now-supports-avx-512-windows-ver-available/
 
Prime95 version 29.6/29.7/29.8
Windows 64-bit: ftp://mersenne.org/gimps/p95v298b5.win64.zip
What's New
1)  Support added for AVX-512 FFTs.
2)  FMA3 FFTs now have slightly higher FFT crossover points.  Soft crossovers are
   no longer used by default.  See undoc.txt.
3)  Torture test dialog box options now based on cache sizes.  Options for performing
   a weaker torture test are available.  Torture tests that use all RAM are now more
   stressful.  In-place vs. not in-place memory accesses now displayed on screen.
   On machines with more than 4GB of memory, blend defaults to 1/16th of RAM.
4)  Add & subtract operations for AVX-512 FFTs are now multithreaded.  This should
   improve performance for P-1 and ECM when using multiple threads.
5)  Benchmark results are now written to results.bench.txt.
6)  JSON results are now available for all work performed.  JSON results are
   written to results.json.txt.
7)  PRP tests with Gerbicz error checking are more immune to hardware errors. 
 
I run Prime95 but not for testing but for finding Prime Numbers.




Starting with version 29.8 Prime95 now defaults to using AVX-512 instructions, confirmed this a while back over on the Prime95 forum https://www.mersenneforum.org/showthread.php?t=24445. However I fail to see what any of this has to do with the issue that I am having? Just to recap at this point with BIOS v1.18 I am able to show that there is some type of what appears to be power throttling taking place when using AVX-512 instructions with HandBrake and with Prime95 Large FTT test. This issue does not exist with BIOS v1.17. I am going to wait and see if someone from EVGA replies on Monday, if they do I will update the post with a better explanation and new details now that I have a better understanding of what is occurring and how to they can try and reproduce it.   
2019/07/21 15:05:21
bcavnaugh
Then you should Open a Service Ticket for this issue.
Remember this is still a Member to Member Forum
I was Going off your Post "Prime95 for example does not cause the issue, but video encoding with HandBrake does." Post #5
https://handbrake.fr/
I was only trying to help you out.
2019/07/21 15:40:51
jasoncodispoti
Sorry if that came across as abrasive... I will call them Monday afternoon if they don’t reply. It will be easier to explain this issue here than it will be on the phone, so I can reference the post with tech support.
2019/07/21 17:41:24
Tech_JoseC
jasoncodispoti
Sorry if that came across as abrasive... I will call them Monday afternoon if they don’t reply. It will be easier to explain this issue here than it will be on the phone, so I can reference the post with tech support.



Didn't find any tickets or emails that could be tied to your account. It sounds like that there may be a bug with this BIOS, however we cannot confirm this yet. I will try doing some testing in the next day or two and I will report my findings with you.
2019/07/21 20:38:29
jasoncodispoti
EVGATech_JoseC
Didn't find any tickets or emails that could be tied to your account. It sounds like that there may be a bug with this BIOS, however we cannot confirm this yet. I will try doing some testing in the next day or two and I will report my findings with you.



I just submitted the ticket, should be good to go. Also here is an updated description of the issue along with the results of some of the recent testing that I have done... (same info is in the ticket I submitted)
 
About 3 weeks ago I upgraded the BIOS on my EVGA X299 Dark to BIOS v1.18. I have been running it without issue since the upgrade however recently I was using my PC to do some video encoding and observed some odd behavior with the CPU ratio and subsequently the CPU frequency.​
 
Issue Description: 
I noticed while using HandBrake to encode a video that even though I had the CPU ratio set to x43 (4.3GHz) in the BIOS with no AVX2 or AVX-512 offset configured. That the CPU was not running at 4.3GHz instead it was operating around 4.0GHz.
 
PC Build:
Motherboard, EVGA X299 Dark
CPU, Intel i7-9800x
Memory, Corsair Dominator Platinum 32GB DDR4 3200MHz
GPU, EVGA RTX 2080ti FTW3 Ultra Gaming Hydro Cooper
Power Supply, SuperNOVA 1000 P2
 
Initial Trouble Shooting:
 Initially I thought the issue was related to thermals however HWInfo64 was reporting that all temperatures were normal; CPU=58C and VRM=52C.
Since the most recent change to the PC was the update to the BIOS that I had preformed a few weeks back. I decided to switch to one of the alternative BIOS chips on the motherboard and see if the same issue was present with BIOS v1.17, it was not it appears that this issue is isolated to BIOS v1.18.
 
Test #1 Prime95:
BIOS Settings, v1.18 all settings are set to default except for the following; CPU Multiplier Control = Manual Ratio Limit x43, AVX2 Negative Offset = 0, AVX3 Negative Offset = 0, VCORE = Override @ 1.250v. TJMax value was manually set to 95C since the motherboard does not auto detect the correct value (bug that I have previously reported with BIOS v1.17).
Through a great deal of testing I have found that this issue only presents when certain loads are applied to the CPU. It has to be an AVX-512 load and it had to either be a load applied by HandBrake when encoding h.264 video or you can use Prime95 v29.8 Torture Test Large FFT.
For this test I used Prime95.
While running the test the CPU ratio dropped to x40 which resulted in a final CPU frequency of 4.0GHz. CPU temperature stayed around 60C and VRM temp stayed around 54C. Using a Kill-A-Watt meter I was able to determine that the PC as a whole was pulling about 338w at the wall. Idle power consumption was around 189w at the wall which would put CPU power consumption at an estimated 149w at the wall.
 
Test #2 Prime95:
I repeated the same test from “Test #1 Prime95” listed above with the same settings\parameters however for this test I lowered VCORE voltage to 1.200v.
While running the test the CPU ratio dropped to x42 which resulted in a final CPU frequency of 4.2GHz. CPU temperature stayed around 56C and VRM temp stayed around 50C. Using a Kill-A-Watt meter I was able to determine that the PC as a whole was pulling about 323w at the wall. Idle power consumption was around 189w at the wall which would put CPU power consumption at an estimated 134w at the wall.
Take note that in this test compared to “Test #1 Prime95” that there was a slight droppage in estimated CPU power consumption. Also make note that the CPU ratio increased to x42 instead of the previous x40. I believe that the slight drop in wattage is what allowed the CPU to clock higher in this test.
 
Test #3 Prime95: 
I repeated the same test from “Test #2 Prime95” listed above with the same settings\parameters however for this test I lowered VCORE voltage to 1.180v.
While running the test the CPU ratio remained at x43 which resulted in a final CPU frequency of 4.3GHz. This is the frequency that the CPU should be operating at per the settings configured in the BIOS. CPU temperature stayed around 63C and VRM temp stayed around 50C. Using a Kill-A-Watt meter I was able to determine that the PC as a whole was pulling about 318w at the wall. Idle power consumption was around 189w at the wall which would put CPU power consumption at an estimated 129w at the wall.
Take note that in this test power consumption was once again lower than the previous test and as a result the CPU ratio remained at the configured setting in the BIOS of x43 resulting in a final CPU frequency of 4.3GHz.

Note:
While not specifically mentioned above CPU C States were also disabled in the BIOS and the High Performance power plan was selected within Windows, with all power savings features disabled. 
 
It appears that there is some type of power throttling that is taking place when running AVX-512 instructions with BIOS v1.18. I have confirmed multiple times by repeating the above tests with BIOS v1.17 that this DID NOT occur with BIOS v1.17. I am able to reproduce very similar results when using Handbrake while encoding H.264 video files.
 
It is also worth noting that at one point while testing and using the Intel Extreme Tuning application it did indicate that there was “Current Limit Throttling” taking place on the CPU. I am not sure how reliable that error is since the reporting of it is not always and HWINfo64 did not indicate that there was an issue. However from my testing that I have done thus far it would appear that this is the issue… some sort of power limit that has been put in place in BIOS v1.18.
I was provided a BETA BIOS to resolve an issue that I found in BIOS v1.17 and it appears to function as normal.
Please let me know if there is anything that you need from me or if you need me to do additional testing.
Thanks!


​​
 
2019/07/24 09:24:58
EVGA_Lee
As an update, we can reproduce the issue.  It appears to be a microcode issue at the moment when using the Vcore override mode, and we've reached out to Intel.  We've also confirmed this happens on boards from at least one other vendor.
2019/07/24 10:27:03
jasoncodispoti
EVGATech_LeeM
As an update, we can reproduce the issue.  It appears to be a microcode issue at the moment when using the Vcore override mode, and we've reached out to Intel.  We've also confirmed this happens on boards from at least one other vendor.




You guys are awesome, seriously the best customer support out there! Thanks for the update. 
2019/07/24 11:02:23
jollydet
Thanks for the feedback, great CS.
2019/07/24 17:06:39
DMIINC
jasoncodispoti
EVGATech_JoseC
Didn't find any tickets or emails that could be tied to your account. It sounds like that there may be a bug with this BIOS, however we cannot confirm this yet. I will try doing some testing in the next day or two and I will report my findings with you.



I just submitted the ticket, should be good to go. Also here is an updated description of the issue along with the results of some of the recent testing that I have done... (same info is in the ticket I submitted)
 
About 3 weeks ago I upgraded the BIOS on my EVGA X299 Dark to BIOS v1.18. I have been running it without issue since the upgrade however recently I was using my PC to do some video encoding and observed some odd behavior with the CPU ratio and subsequently the CPU frequency.​
 
Issue Description: 
I noticed while using HandBrake to encode a video that even though I had the CPU ratio set to x43 (4.3GHz) in the BIOS with no AVX2 or AVX-512 offset configured. That the CPU was not running at 4.3GHz instead it was operating around 4.0GHz.
 
PC Build:
Motherboard, EVGA X299 Dark
CPU, Intel i7-9800x
Memory, Corsair Dominator Platinum 32GB DDR4 3200MHz
GPU, EVGA RTX 2080ti FTW3 Ultra Gaming Hydro Cooper
Power Supply, SuperNOVA 1000 P2
 
Initial Trouble Shooting:
Initially I thought the issue was related to thermals however HWInfo64 was reporting that all temperatures were normal; CPU=58C and VRM=52C.
Since the most recent change to the PC was the update to the BIOS that I had preformed a few weeks back. I decided to switch to one of the alternative BIOS chips on the motherboard and see if the same issue was present with BIOS v1.17, it was not it appears that this issue is isolated to BIOS v1.18.
 
Test #1 Prime95:
BIOS Settings, v1.18 all settings are set to default except for the following; CPU Multiplier Control = Manual Ratio Limit x43, AVX2 Negative Offset = 0, AVX3 Negative Offset = 0, VCORE = Override @ 1.250v. TJMax value was manually set to 95C since the motherboard does not auto detect the correct value (bug that I have previously reported with BIOS v1.17).
Through a great deal of testing I have found that this issue only presents when certain loads are applied to the CPU. It has to be an AVX-512 load and it had to either be a load applied by HandBrake when encoding h.264 video or you can use Prime95 v29.8 Torture Test Large FFT.
For this test I used Prime95.
While running the test the CPU ratio dropped to x40 which resulted in a final CPU frequency of 4.0GHz. CPU temperature stayed around 60C and VRM temp stayed around 54C. Using a Kill-A-Watt meter I was able to determine that the PC as a whole was pulling about 338w at the wall. Idle power consumption was around 189w at the wall which would put CPU power consumption at an estimated 149w at the wall.
 
Test #2 Prime95:
I repeated the same test from “Test #1 Prime95” listed above with the same settings\parameters however for this test I lowered VCORE voltage to 1.200v.
While running the test the CPU ratio dropped to x42 which resulted in a final CPU frequency of 4.2GHz. CPU temperature stayed around 56C and VRM temp stayed around 50C. Using a Kill-A-Watt meter I was able to determine that the PC as a whole was pulling about 323w at the wall. Idle power consumption was around 189w at the wall which would put CPU power consumption at an estimated 134w at the wall.
Take note that in this test compared to “Test #1 Prime95” that there was a slight droppage in estimated CPU power consumption. Also make note that the CPU ratio increased to x42 instead of the previous x40. I believe that the slight drop in wattage is what allowed the CPU to clock higher in this test.
 
Test #3 Prime95: 
I repeated the same test from “Test #2 Prime95” listed above with the same settings\parameters however for this test I lowered VCORE voltage to 1.180v.
While running the test the CPU ratio remained at x43 which resulted in a final CPU frequency of 4.3GHz. This is the frequency that the CPU should be operating at per the settings configured in the BIOS. CPU temperature stayed around 63C and VRM temp stayed around 50C. Using a Kill-A-Watt meter I was able to determine that the PC as a whole was pulling about 318w at the wall. Idle power consumption was around 189w at the wall which would put CPU power consumption at an estimated 129w at the wall.
Take note that in this test power consumption was once again lower than the previous test and as a result the CPU ratio remained at the configured setting in the BIOS of x43 resulting in a final CPU frequency of 4.3GHz.

Note:
While not specifically mentioned above CPU C States were also disabled in the BIOS and the High Performance power plan was selected within Windows, with all power savings features disabled. 
 
It appears that there is some type of power throttling that is taking place when running AVX-512 instructions with BIOS v1.18. I have confirmed multiple times by repeating the above tests with BIOS v1.17 that this DID NOT occur with BIOS v1.17. I am able to reproduce very similar results when using Handbrake while encoding H.264 video files.
 
It is also worth noting that at one point while testing and using the Intel Extreme Tuning application it did indicate that there was “Current Limit Throttling” taking place on the CPU. I am not sure how reliable that error is since the reporting of it is not always and HWINfo64 did not indicate that there was an issue. However from my testing that I have done thus far it would appear that this is the issue… some sort of power limit that has been put in place in BIOS v1.18.
I was provided a BETA BIOS to resolve an issue that I found in BIOS v1.17 and it appears to function as normal.
Please let me know if there is anything that you need from me or if you need me to do additional testing.
Thanks!


​​
 




Same here. I was pulling my hair out trying to figure out the problem. For me on X299 micro 2 it downclocks 500 MHz when using AIDA64 FPU test. Power is limited to 140W in HW Monitor and AIDA64 sensor page. It will not move over that regardless what setting I use in BIOS or Intel XTU. Temps are fine, mid 70's on CPU and 57 deg C max on VRM. Core i9 9900x @ 4.70 GHz.
2019/07/25 04:46:41
jasoncodispoti
DMIINC
 
 
Same here. I was pulling my hair out trying to figure out the problem. For me on X299 micro 2 it downclocks 500 MHz when using AIDA64 FPU test. Power is limited to 140W in HW Monitor and AIDA64 sensor page. It will not move over that regardless what setting I use in BIOS or Intel XTU. Temps are fine, mid 70's on CPU and 57 deg C max on VRM. Core i9 9900x @ 4.70 GHz.




It will be interesting to see if what the outcome of this is... I would say at this point if AVX-512 is something that you use than stay with BIOS v1.17 for now. 

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