SuperPi on 3.8GHz Prescott...

[996GT2]

My friend just got his RMA mobo from Gigabyte today, it has the Intel 945 chipset. He put in his Prescott 530 (3 GHz, 1 MB L2) and overclocked it to 3.75 GHz on 2 GB of OCZ Gold DDR2-667 that I let him borrow until I got my CPU back from Newegg...However, after the OC, his superPi 1M time went up to around 41 seconds, versus about 38 seconds when he had a 3.3 GHz OC on his 2 older mobos, an Asus P5LD2 and an ECS Hybrid mobo.

His OC:
250 FSB * 15X Multi
RAM running at 666 Mhz
Motherboard is made by Gigabyte with Intel 945 chipset (not sure of exact model right now)

Other specs:
XFX 7800GT
Mad Dog 600W Modular PSU
Scythe Ninja heatsink

Anyone know what's causing the increased SuperPi time?

 

[F1shF4t]

Maybe its throtling ? that would sertainly kill performance, check the temps on it.

 

[MDme]

I agree, throttling would be the most likely issue. However the use of different mobos and possible system drivers could affect it a bit too. also, are you windows installs the same? processes can affect the resources available to the cpu.

 

[dguy6789]

It is probably throttling.

 

[Duvie]

also check to see if memorty setting sare on auto...it may have changed the memory divider and cas timings which will have an effect on superpi times...

 

[996GT2]

He killed most of the processes before running SuperPi, so I don't think other processes are stealing resources...

Also he has a scythe Ninja with 120mm fan installed on his prescott which is only using 1.45-1.5V right now (set to 1.5V in BIOS but CPU-Z says 1.44V), so I don't think it's a temperature issue, but I will check with him

Lastly the memory divider is manually set, not left on auto...superPi times didn't change much when different dividers were used running the RAM at 733mhz and around 600 mhz

 

[Thor86]

Most likely a memory setting issue as well. 1T command rate is enabled?

 

[stevty2889]

I had to use water cooling to keep my 5xx series prescott from throttling at those speeds, so there definatly is a chance he's throttling. Download and run throttlewatch, then put the CPU under heavy load. 1.5v is getting up there in voltage for a prescott, and raising the voltage lowers the temp at which throttling kicks in.