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

[Justin Piszcz <jpiszcz@lucidpixels.com>]

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.