Dual Core 3.0 GHz
Quad Core 2.4 GHz
First number, dual, second, quad, third, change as a percentage
PCMark05 9091 8853 -3%
SysMark 2007, E-Learning 167 140 -16%
SysMark 2007, Video Creation 131 151 15%
SysMark 2007, Productivity 152 138 -9%
SysMark 2007, 3D 160 148 -8%
Quake 4 136 117 -15%
F.E.A.R. 123 110 -10%
Company of Heroes 173 161 -7%
Lost Planet 62 54 -12%
Lost Planet "Concurrent Operations" 62 81 30%
DivX 6.6 65 64 0%
Xvid 1.2 43 45 5%
H.264 QuickTime Pro 7.2 189 188 0%
iTunes 7.3 MP3 encoding 110 131 -16%
3ds Max 9 SP2 4.95 6.61 33%
Cinebench 10 5861 8744 49%
Excel 2007 39.9 24.4 63%
WinRAR 3.7 188 180 5%
Photoshop CS3 70 73 -4%
Microsoft Movie Maker 6.0 73 80 -9%
Most programs and games currently benefit more from a higher clocked DUAL than a lower clocked QUAD. At the time being, 2 > 4. Get the E8400.
" It's mostly what I would expect-- only rendering and encoding tasks exploit parallelism enough to overcome the 25% speed deficit between the dual and quad core CPUs. Outside of that specific niche, performance will actually suffer for most general purpose software if you choose a slower quad-core over a faster dual-core.
However, there were some surprises in here, such as Excel 2007, and the Lost Planet "concurrent operations" setting. It's possible software engineering will eventually advance to the point that clock speed matters less than parallelism. Or eventually it might be irrelevant, if we don't get to make the choice between faster clock speeds and more CPU cores. But in the meantime, clock speed wins most of the time. More CPU cores isn't automatically better. Typical users will be better off with the fastest possible dual-core CPU they can afford."
-Codinghorror.com
also,
http://ve3d.ign.com/articles/news/195/Ask-Tim-Quad-vs-Dual-Cores-for-Gaming