Case: 225446: Linux 2.6.21.3 does not work with 8GB of RAM on Intel 965WH

[Justin Piszcz <jpiszcz@lucidpixels.com>]

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On Wed, 30 May 2007, Justin Piszcz wrote:

>
>
> On Wed, 30 May 2007, Zoltan Boszormenyi wrote:
>
>> Hi,
>> 
>>> Look at how slow the raid benchmarks are in dmesg with 8GB of memory!
>>> 
>>> [   59.592560] raid6: using algorithm sse2x4 (476 MB/s)
>>> [   59.597558] raid5: using function: generic_sse (56.000 MB/sec)
>>> 
>>> Yikes!
>>> 
>>> With mem=4096M:
>>> [   60.336352] raid6: using algorithm sse2x4 (6804 MB/s)
>>> [   60.341345] raid5: using function: generic_sse (8552.000 MB/sec)
>>> 
>>> What is going on here?
>>> 
>>> Justin.
>> 
>> I saw a similar effect on a P5 board that could
>> only cache 64MB of memory a long time ago.
>> Putting more memory into it made the machine slower
>> and e.g. made the sym2 driver giving up at initialization.
>> Maybe it's a modern reincarnation of the problem?
>> 
>> Best regards,
>> Zoltán Böszörményi
>> 
>
> I see, so Intel 965 motherboards do not work with 8GB of memory?  Or is this 
> a Linux issue?
>
> I have an Intel Case ID open 225446 but so far we have not gotten anywhere 
> with this problem.  Currently I have 8GB in the machine and boot with 
> mem=4096M.  Was there any type of fix?  Any recommendations as to what I can 
> do?  Continue to speak with Intel?  Or perhaps someone with more knowledge of 
> the kernel and chime in as to what exactly is happening here?
>
> Justin.

Adding Intel to CC list.