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.