The 64bit OS probably makes most of the difference in speed.

F2bnp wrote:

The 64bit OS probably makes most of the difference in speed.

This is my random shot in the dark guess. Perhaps windows 7 being a newer OS takes better advantage of the hardware.

Along with it being a 64bit OS 😜

Quote from AsRock site: "If you use AM3 / AM2+ CPU on AM2 chipset motherboard, the system bus speed will downgrade from HT3.0 (5200 MT/s) to HT1.0 (2000 MT/s), but the CPU frequency will not be influenced." If the HT bus really is downclocked that much, well it seems that there is your problem.

I'm running the same superpii on each so it must be a 32bit program. What I see on the web is that running 32bit software on a 64bit OS might give a small performance drop.

And other reports seem to show 7 is not significantly faster than xp [some evidence of the reverse I think].

I was wondering if it could be the chipset. The NB frequency on the asrock is 1600mhz, its 2ghz on the sapphire.

edit: thanks aideka, I never really understood what that meant but assumed it would be true for any am3 cpu used in an am2/2+ board. But in fact the sapphire page says: "AMD 790FX chipset based PCs feature the latest HT3 2000MHz bus technology".

Guess that clinches it, it's the chipset.

CPU-Z should tell you what speed the frontside bus is running at.

Use a linux / Windows live CD to rule out software differences?

Yeah I could try that. I've just bought a new asus 790fx board to replace the asrock one 😁 .

edit: wow, new mobo gives superpii at 20.7, and 3dmark1001se gives 46k compared to 33-34k before.