When will my CPU become a Bottleneck???

[rambostyrer]

I´m buying a new PC, and I'm in doubt on how much CPU power i Need.

The basis of the PC will be a

AsRock p55 extreme motherboard
4 gb pc 10600 ddr3 memory
and a as powerfull a graphics card as i can run. (Radeon 5850 or 5870, would be my prefered choices, with a later option for Crossfire)

I have 3 different CPU options, a I3 530, I5 750 or a I7 860

so my question is: how powerfull graphics setups can each of these CPU's run without becomming a serious bottleneck??


(this is ment for games like, GTA IV, Assasins CreedII, and other games demanding high end graphics)

p.s. pardon my english, but I'm from Denmark

 

[wolfram23]

Your best bang for your buck is going to be the i5 750. The i3 530 is fine but only has 2 cores, and there's a growing trend to support multi threading in gaming. And DX11 allows multi threading as well. The i7 860s are more if you want a cheaper alternative to the i7 9xx series to do things like encoding and other very heavy CPU multithreading apps. This doesn't really apply to gaming.

I ran benchmarks, and I only noticed there being a CPU bottleneck in one scenario. I compared single to CF 5850s in FurMark. Running a mere 1280x1050 at 0xAA, I only saw about 5fps increase between single and CF. Bring the resolution up to 1920x1080 and the increase stretched to 82%, and with 4xAA it was 90%.

 

[rambostyrer]

thanks for the answers!



so if i go for the I5 750 would 2*5870 in crossfire, be an option or would i need a more powerfull cpu for that???

just to spell it completely out:

 

[Emperus]

Get the i5 750 and overclock if you feel it bottlenecking the two 5870 setup..

 

[wolfram23]

Depends on the resolution, but at, say, 1920x1080 you will not get CPU bottlenecked in any games even with two 5870s. And, the i5 750 is easily overclockable (I gained over 1ghz)