Archive for September, 2007

New rig: overclocking and benchmarks

Saturday, September 22nd, 2007

I bought an Intel Core 2 Duo E6750 by accident for a customer while the motherboard only supported 1066MHz FSB CPU’s. I was actually waiting for AMD’s new generation CPU’s. The AMD Opteron ‘Barcelona’ is just launched (september 10, 2007) and the desktop version, AMD Phenom will be released at the end of the year. The introduction price problably will be high and i don’t want to wait a half year till the prices drop. So i decided to build my rig based on the E6750.

Closeup of Intel Core 2 Duo E6750

Intel Core 2 Duo E6750 (2667MHz core clock, 1333MHz FSB)
Gigabyte P35-DS3R motherboard
Club3D Geforce 8600GTS Graphics card
2 x 1024MB PC2 6400 (Corsair CM2X1024-6400C40) memory
1 x Western Digital Raptor 74GB 10k rpm
Antec TrueBlue 480W PSU

CPU Overclocking
The E6750 is a very good overclocker. With auto voltage control (it goes up to 1.41V) of the motherboard i could reach ~3850 MHz. By manual increasing the voltage to 1.55V i could reach 4016MHz. At first sight it was running very stable. It had no problems with a long SuperPI run. But it crashed while running 3DMark07. Nevertheless this is a stunning overclock considering i only used the Intel stock cooler.

CPU-Z max overclock

The gigabyte motherboard is very good performing and has lots of overclocking features. It can even handle FSB’s far beyond 2000MHz. There is only one downside: The minimal memory multiplier is 2. It is then running in sync with the FSB.
But with huge overclocks the memory can be a bottlneck.
My memory was runnin at 1000MHz instead of the defult 800MHz on 4GHz. The memory is most problably the reason why it could not clock higher.

Gigabyte P35-DS3R BIOS

Benchmarks: SuperPi 1.1
Due to its big cache of 4MB is performs VERY GOOD in SuperPi 1M.

SuperPi 1M E6750 @ 2667 MHz: 18 seconds
SuperPi 1M E6750 @ 4016 MHz: 12 seconds

Benchmarks: FutureMark 3DMark05

E6750 @ 2667MHz, 8600GTS @ stock core, mem: 11840 points
E6750 @ 3904MHz, 8600GTS @ 770MHz core, 2180MHz mem: 13492 points

Benchmarks: FutureMark 3DMark06
E6750 @ 2667MHz, 8600GTS @ stock core, mem: 5678 points
E6750 @ 3904MHz, 8600GTS @ stock core, mem: 5962 points
E6750 @ 3904MHz, 8600GTS @ 725MHz core, 2016MHz mem: 6206 points
E6750 @ 3904MHz, 8600GTS @ 740MHz core, 2050MHz mem: 6253 points
E6750 @ 3904MHz, 8600GTS @ 750MHz core, 2150MHz mem: 6470 points
E6750 @ 3904MHz, 8600GTS @ 760MHz core, 1180MHz mem: 6503 points
E6750 @ 3904MHz, 8600GTS @ 775MHz core, 2200MHz mem: 6632 points

Benchmarks: FutureMark PCMark05
E6750 @ 2667MHZ: 6966 points
E6750 @ 3904MHz: 8938 points

Energy consumption
Beneath are my results of the relative energy consumption of the processor using different options. For the stress test i used one (one core) or two (both cores) SuperPi instances.

stock clock frequency
2666MHz (8×333) – idle – vcore 1.31V – 106W
2000MHz (6×333) – idle Enhanced C1 state – vcore 1.104V – 100W
2666MHz (8×333) – stressed 1 core – vcore 1.31V – 128W
2666MHz (8×333) – stressed 2 cores – vcore 1.31V – 140W

3904MHz (8×488) – idle – vcore 1.55V – 135W
3904MHz (8×488) – stressed 1 core – vcore 1.55V – 184W
3904MHz (8×488) – stressed 2 cores – vcore 1.55V – 202W

3808MHz (8×476) – idle – vcore 1.41V – 121W
2856MHz (6×476) – idle Enhanced C1 state – vcore 1.41V – 122W
3808MHz (8×476) – stressed 1 core – vcore 1.41V – 157W
3808MHz (8×476) – stressed 2 cores – vcore 1.41V – 172W