Help with improving mysql performance on 6.2PRE
cswiger at mac.com
Fri Oct 13 11:49:09 PDT 2006
On Oct 13, 2006, at 11:26 AM, Eric Hodel wrote:
>>> Or did that change recently?
>> It's only on certain systems, apparently.
> Is there a list of systems where it is safe to use the TSC with
> SMP? Or some script we can run?
The problem of the TSC clocks getting out of sync affects pretty much
all AMD X2 dual-core CPUs, as well as the older 32-bit Althon MP
CPUs; the Intel Xeon and Core Duo CPUs seem to do a lot better,
although older Intel CPUs have also been reported to show problems
with the TSC.
Disabling the fancy power-management capabilities (SpeedStep,
PowerNow, Cool-n-quiet) to prevent the system from adjusting the CPU
clock frequencies seems to reduce the extent of the problem.
However, if you want your system clock to work reliably, using the
ACPI-safe or i8254 timecounters is going to do much better than using
the faster-but-unreliable TSC method.
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