[coreboot] Overclocking Opteron 6200 from coreboot ?

[BogDan Vatra]

Hi Tomothy,

2017-07-04 21:53 GMT+03:00 Timothy Pearson <tpearson at 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.