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On 07/04/2017 07:20 AM, BogDan Vatra wrote:
Hello,
I finally managed to complete my system [0], even that all CPUs together are *almost* twice faster than my i7, I want to be change *almost* into *more than*, and the only way to do that is to overclock my CPUs (or to buy more expensive ones). Now the big question is: Is it possible to do it from coreboot? If yes, then will the CPU temperature protection still work? E.g. will it turn off the computer if the cpu temp will go above 70 degree Celsius? If is not possible from coreboot, then, will it be possible to do it from Linux? Does anyone has experience on this matter that can share ?
Thanks, BogDan.
[0] CPU: 2x Opteron 6276 MB: KGPED16 other uninteresting things.
Yes, it can be done with significant effort (I wrote the software to do so, which remains unreleased at this time). That being said, the Opterons already consume a massive amount of electrical power compared to the i7. In my experience if you want to overclock significantly you need to start dropping CPU load (i.e. unloading cores) to avoid burning out mainboard circuitry (or PSU wiring!). The increase in power consumption versus clock rate is exponential (as you probably know), but when you start with dual 115W CPUs that can go into some serious power very quickly.
For reference, I have a 6-core Opteron here (C32) that overclocked to 4.2GHz stably, but it is attached to a massive 5U air cooler and uses over double its rated TDP in the process. This was also a hand-picked HE chip as other chips did not overclock that well. The power reporting gives bad numbers under overclock, while the hard thermal limits continue to function. Furthermore, overclocking these chips requires disabling large chunks of the power management functionality, meaning you'll be using power as if the system is under full load even when it isn't.
On the balance, I chose not to release the tools due to the significant liability involved and the fact that (given the AMD-imposed limitations that had to be hacked around) they not going to help most people do anything other than burn out hardware and waste power. Furthermore, I'd rather see community effort focused on newer architectures (ARM, POWER) than trying to squeeze a bit more performance / a bit more time from a terminally non-free architecture (x86).
If you _really_ want to try an overclock anyway, I might be able to provide the overclocking tools under NDA, but I don't see a cost / benefit reason to publicly release them at this time ("costs" largely related to legal liability and such due to the fact that, misused, these tools will quite happily cause hardware damage).
- -- Timothy Pearson Raptor Engineering +1 (415) 727-8645 (direct line) +1 (512) 690-0200 (switchboard) https://www.raptorengineering.com
Hi Tomothy,
2017-07-04 21:53 GMT+03:00 Timothy Pearson tpearson@raptorengineering.com:
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On 07/04/2017 07:20 AM, BogDan Vatra wrote:
Hello,
I finally managed to complete my system [0], even that all CPUs together are *almost* twice faster than my i7, I want to be change *almost* into *more than*, and the only way to do that is to overclock my CPUs (or to buy more expensive ones). Now the big question is: Is it possible to do it from coreboot? If yes, then will the CPU temperature protection still work? E.g. will it turn off the computer if the cpu temp will go above 70 degree Celsius? If is not possible from coreboot, then, will it be possible to do it from Linux? Does anyone has experience on this matter that can share ?
Thanks, BogDan.
[0] CPU: 2x Opteron 6276 MB: KGPED16 other uninteresting things.
Yes, it can be done with significant effort (I wrote the software to do so, which remains unreleased at this time). That being said, the Opterons already consume a massive amount of electrical power compared to the i7. In my experience if you want to overclock significantly you need to start dropping CPU load (i.e. unloading cores) to avoid burning out mainboard circuitry (or PSU wiring!). The increase in power consumption versus clock rate is exponential (as you probably know), but when you start with dual 115W CPUs that can go into some serious power very quickly.
I'm not planning to significantly overclock, I'm dreaming for 15% to 30% increase :).
For reference, I have a 6-core Opteron here (C32) that overclocked to 4.2GHz stably, but it is attached to a massive 5U air cooler and uses over double its rated TDP in the process. This was also a hand-picked HE chip as other chips did not overclock that well. The power reporting gives bad numbers under overclock, while the hard thermal limits continue to function. Furthermore, overclocking these chips requires disabling large chunks of the power management functionality, meaning you'll be using power as if the system is under full load even when it isn't.
WOW 4.2GHz!!! I was hopping for 2.8GHz maybe push my luck to 3GHz but no more than that :) ! I have 2 x NH-U9DO A3 which seems to do a good job, even I choose to use the very low noise profile cables*, they keep my CPUs temp ~20 degrees and ~30 when they are in full load all cores.
* The NH-U9DO A3 coolers have 3-pin cables for fans and I chosen the cables instead to set the correct jumper on the motherboard because when I set the jumper for 3-pin cable, the motherboard starts to do a strange noise which is louder than all the fans :). BTW it's just me or it happened to someone else ?
On the balance, I chose not to release the tools due to the significant liability involved and the fact that (given the AMD-imposed limitations that had to be hacked around) they not going to help most people do anything other than burn out hardware and waste power.
Are these tools part of the coreboot or I can use them from Linux? If they are Linux tools then I can first try them using ASUS' BIOS which I know for sure that it has the thermal protection (Long funny story short: I forgot to remove the plastic protection from one of the coolers and in full load the computer shutdown after ~20m :) )
Furthermore, I'd rather see community effort focused on newer architectures (ARM, POWER) than trying to squeeze a bit more performance / a bit more time from a terminally non-free architecture (x86).
I didn't knew that ARM is a free architecture ... I knew that OpenPower and OpenSPARC and RISCV are but I had no idea about ARM ... BTW is OpenSPARC still alive? Or it died with Sun?
If you _really_ want to try an overclock anyway, I might be able to provide the overclocking tools under NDA, but I don't see a cost / benefit reason to publicly release them at this time ("costs" largely related to legal liability and such due to the fact that, misused, these tools will quite happily cause hardware damage).
Yep, I *REALLY* want to try an overclock anyway :) ! I'm planning only to overclock the CPU to 2.8 - 3 GHz. I also want to mention that I understand your reason for not make the public.
Thanks a lot!
Cheers, BogDan.
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BogDan Vatra -
Timothy Pearson