PDA

View Full Version : disabling hardware data prefetch


Steve
April 8th 06, 09:19 PM
Does anyone know how to disable hardware data prefetch on the Athlon64
architecture?

I want to turn this feature off because I want to use software
prefetching instructions to load cache lines from memory and I don't
want the hardware prefetcher interfering with my software prefetch
schedule.

The Pentium and Xeon processors also have hardware prefetching and it
can be disabled by zeroing a bit in a MSR (Model Specific Register).
Specifically, it is bit 9 of MSR "IA32_MISC_ENABLE." The
Athlon/Opteron docs don't show a corresponding MSR (I believe it is
specific to Pentium/Xeon). And the AMD docs don't indicate any way
of disabling hardware prefetch.

Thanks,

-- Steve