RAM speed problem on Supermicro H8QGI (Family 15h)

[Константин Аладышев]

I have server Supermicro H8QGI board with 4 AMD Opteron f15 processors and 128 GB RAM (16x8Gb, 4 dimms per socket, 1 dimm per channel).I've tested my board in STREAM and noticed that coreboot gives RAM speed 5 times slower than original BIOS (16 MB/s against 80 MB/s). What can lead to this problem?Is it family 15h or motherboard issue? Does another families have such problem?I've dumped registers from coreboot and original BIOS. After that i enabled/disabled some functions in buildOps.c to make dumps look more similar.Now dumps allmost identical (but RAM speed problem still exist). Also i should mention that original BIOS have HT-ASSIST feature enabled, but i can't enable it in coreboot (http://www.coreboot.org/pipermail/coreboot/2012-December/073001.html)But according to this link http://www.amd.com/us/products/server/processors/six-core-opteron/Pages/six-... HT-ASSIST can increase performance by up to 60% (not 500%!). So i think it isn't the main problem.

[WANG Siyuan]

Hi, Константин
Did you try to change BLDCFG_MEMORY_BUS_FREQUENCY_LIMIT and
BLDCFG_MEMORY_CLOCK_SELECT in
src/mainboard/supermicro/h8qgi/buildOpts.c ?
BLDCFG_USE_HT_ASSIST can't be set as TRUE on h8qgi now. I am sorry but
I don't know how to debug this issue.

On Thu, Jan 24, 2013 at 3:42 PM, Константин Аладышев
 wrote:
> I have server Supermicro H8QGI board with 4 AMD Opteron f15 processors and
> 128 GB RAM (16x8Gb, 4 dimms per socket, 1 dimm per channel).
>
> I've tested my board in STREAM and noticed that coreboot gives RAM speed 5
> times slower than original BIOS (16 MB/s against 80 MB/s).
>
> What can lead to this problem?
>
> Is it family 15h or motherboard issue? Does another families have such
> problem?
>
> I've dumped registers from coreboot and original BIOS. After that i
> enabled/disabled some functions in buildOps.c to make dumps look more
> similar.
>
> Now dumps allmost identical (but RAM speed problem still exist).
>
> Also i should mention that original BIOS have HT-ASSIST feature enabled, but
> i can't enable it in coreboot
> (http://www.coreboot.org/pipermail/coreboot/2012-December/073001.html)
>
> But according to this link
> http://www.amd.com/us/products/server/processors/six-core-opteron/Pages/six-...
> HT-ASSIST can increase performance by up to 60% (not 500%!). So i think it
> isn't the main problem.