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View Full Version : Inconcistency in memory latency benchmark



Sheena
12-10-2010, 04:29 PM
Hi all. I tested my pc memory latency with sisoft sandra and i got some weird results. In fact i get 2 types of results, each one being really consistent though.

1st type (Right results for my pc)

Memory latency : 69ns
L2 cache latency : 18 clocks

2nd type ("high latency" benchmark)

Memory latency : 79ns
L2 cache latency : 21 clocks

It's pretty much random. I can test and get the 1st type then i retest 15 mins later and i get the 2nd type. Nothing else is running on my computer when i test (cpu usage at 0%).

Now my question is if it's something normal with sisoft sandra or something may be wrong with my computer ?

My PC :

Core 2 Duo E8400 @ 3.6ghz (400x9)
4GB Kingston HyperX DDR2-1066 5-5-5-18-2T
Windows XP SP3

P.S. Sorry english is not my native language :P

SoniKalien
12-10-2010, 05:55 PM
Do you have any software installed (or even enabled in bios) that manages clock speeds automatically?

Sheena
12-10-2010, 06:04 PM
Do you have any software installed (or even enabled in bios) that manages clock speeds automatically?

Nah i though it was that at first but i disabled EIST function and C1/C2 state in the bios so the cpu run at 3.6ghz idle. Still i get these weird variations. I even noticed the 2 cores don't even benchmark the same.

Last test :

Core 0 : Memory latency 79ns , L2 cache latency 21 clocks
Core 1 : Memory latency 69ns , L2 cache latency 18 clocks

This is very strange heh.

SoniKalien
12-10-2010, 06:35 PM
Um, yea lol. Try benchmarking with Everest see if you get the same results :)

Speedy Gonzales
12-10-2010, 06:48 PM
Disable speedstep too if the CPU supports it