Re: Kernel 2.6.21.3 does not work with 8GB of RAM on Intel 965WH

Re: Kernel 2.6.21.3 does not work with 8GB of RAM on Intel 965WH

[Zoltan Boszormenyi]

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

Re: Kernel 2.6.21.3 does not work with 8GB of RAM on Intel 965WH

[Justin Piszcz]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1290 bytes --]



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.

Re: Kernel 2.6.21.3 does not work with 8GB of RAM on Intel 965WH

[Zoltan Boszormenyi]

Justin Piszcz írta:
>
>
> 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?

It was certainly a mainboard problem, the same system worked well
on another board with a more capable L2 cache controller.
Or on PPro/P-II boards.

> 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.

I think continue to talk Intel and with the kernel guys,
I don't have experience with machines with so much memory (yet).

Best regards,
Zoltán Böszörményi

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

[Justin Piszcz]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1421 bytes --]



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.