FutureMark 3DMark05 - Multi-Threaded Test	Source: FutureMark

3DMark05 is best suited for the latest generation of DirectX9.0 graphics cards. It is the first benchmark to require a DirectX9.0 compliant hardware with support for Pixel Shaders 2.0 or higher! By combining high quality 3D tests, CPU tests, feature tests, image quality tools, and much more, 3DMark05 is a premium benchmark for evaluating the latest generation of gaming hardware. Prime95 was running in the background to simulate load on a one core.

Prime95 + 3DMark05
Overall:	Points	Ranking
Intel Core 2 Duo E6600	7915
Intel Pentium D 940	7269
Intel Pentium D 840	7974
AMD Athlon64 FX-60 (Socket 939)	11456
AMD Athlon64 4000+ (Socket 939)	7718
AMD Athlon64 FX-62 (Socket AM2)	7846
AMD Athlon64 X2 5000+ (Socket AM2)	7753
AMD Athlon64 X2 4800+ (Socket AM2)	7782
AMD Sempron 3600+ (Socket AM2)	7447
Intel Core 2 Duo E6750 (nVIDIA nForce 650i DDR2 memory)	8452
Intel Core 2 Duo E6750 (Intel P35 Express DDR2 memory)	8414
Intel Core 2 Duo E6750 (Intel P35 Express DDR3 memory)	8046
Intel Core 2 Duo E6750 @ 3.8 GHz (Intel P35 Express DDR2 memory)	8455
CPU:	Points	Ranking
Intel Core 2 Duo E6600	8062
Intel Pentium D 940	4847
Intel Pentium D 840	2186
AMD Athlon64 FX-60 (Socket 939)	5546
AMD Athlon64 4000+ (Socket 939)	5149
AMD Athlon64 FX-62 (Socket AM2)	6356
AMD Athlon64 X2 5000+ (Socket AM2)	6447
AMD Athlon64 X2 4800+ (Socket AM2)	6246
AMD Sempron 3600+ (Socket AM2)	4776
Intel Core 2 Duo E6750 (nVIDIA nForce 650i DDR2 memory)	8766
Intel Core 2 Duo E6750 (Intel P35 Express DDR2 memory)	8736
Intel Core 2 Duo E6750 (Intel P35 Express DDR3 memory)	8312
Intel Core 2 Duo E6750 @ 3.8 GHz (Intel P35 Express DDR2 memory)	10142

When running Prime95 on one of the E6750's cores, the 3DMark05 overall and CPU results obviously fall down a notch. Still, the results are competitive. The overclocked Core 2 Duo E6750 breaks 10k mark in the CPU section. Awesome.

Doom 3 - Multi-Threaded Test	Source: id Software

Doom 3 takes advantage of the latest videocard technology and pushes the processing power of the CPU to its absolute limit. At its highest setting, Ultra quality, texture sizes pass the 500MB mark which means even tomorrow's videocards will have a hard time running everything. The frame rates in the game itself are locked at 60 fps so anything above that point is wasted. Each test is run three times with the third run being recorded. Prime95 was running in the background to simulate load on a one core.

Prime95 + Doom 3
LQ 640x480:	FPS	Ranking
Intel Core 2 Duo E6600	164.8
Intel Pentium D 940	129
Intel Pentium D 840	84.4
AMD Athlon64 FX-60 (Socket 939)	147.8
AMD Athlon64 4000+ (Socket 939)	126.8
AMD Athlon64 FX-62 (Socket AM2)	136.8
AMD Athlon64 X2 5000+ (Socket AM2)	129.1
AMD Athlon64 X2 4800+ (Socket AM2)	124.3
AMD Sempron 3600+ (Socket AM2)	90
Intel Core 2 Duo E6750 (nVIDIA nForce 650i DDR2 memory)	198.3
Intel Core 2 Duo E6750 (Intel P35 Express DDR2 memory)	194.5
Intel Core 2 Duo E6750 (Intel P35 Express DDR3 memory)	183.2
Intel Core 2 Duo E6750 @ 3.8 GHz (Intel P35 Express DDR2 memory)	223.7
HQ 1024x768:	FPS	Ranking
Intel Core 2 Duo E6600	137.5
Intel Pentium D 940	99.3
Intel Pentium D 840	77.5
AMD Athlon64 FX-60 (Socket 939)	126.4
AMD Athlon64 4000+ (Socket 939)	124
AMD Athlon64 FX-62 (Socket AM2)	121.8
AMD Athlon64 X2 5000+ (Socket AM2)	128.7
AMD Athlon64 X2 4800+ (Socket AM2)	118.6
AMD Sempron 3600+ (Socket AM2)	90.4
Intel Core 2 Duo E6750 (nVIDIA nForce 650i DDR2 memory)	152.6
Intel Core 2 Duo E6750 (Intel P35 Express DDR2 memory)	153.1
Intel Core 2 Duo E6750 (Intel P35 Express DDR3 memory)	145.7
Intel Core 2 Duo E6750 @ 3.8 GHz (Intel P35 Express DDR2 memory)	174.6

If you're going to be running something intensive in the background it looks like the Intel Core 2 Duo E6750 has the power to go around. Just look at those HQ 1024x768 framerates with Prime 95 running...