What CPU will bottle neck 4850 CF?

[drdoom]

I was wondering. I have a 5400+ BE which probably can do 3.2ghz. Will that be a significant bottle neck for a pair of 4850's? I will upgrade to a X3 or X4 at some point but not sure when.

[anubis44]

I was wondering. I have a 5400+ BE which probably can do 3.2ghz. Will that be a significant bottle neck for a pair of 4850's? I will upgrade to a X3 or X4 at some point but not sure when.

Since nobody else has ventured to try, I will try to answer your question despite the fact that I do not have a very precise answer for you.

The answer basically boils down to resolution. Based on what I've seen, in very general terms you need at least a dual core CPU to drive most modern (single) graphics cards, such as the 8800GT and up (NVidia)/4850 and up (ATI). If you play your games at 1680x1050 resolution, even a single 4850 will play most games tolerably with a decent dual core CPU (Your overclocked 5400BE is probably the very minimum dual core that fits this category).

Once you get two 4850s in crossfire, your 5400BE CPU will start to become a bottleneck even at 1680x1050, although you will see anything from negligable to nearly 100% performance improvements in frame rates depending on the game, even with that 5400 cpu. If you play at 1920x1200 (or higher), your cpu is definitely holding back a 4850 crossfire setup quite significantly.

This article here shows how even a QX9770 overclocked to 3.8GHz is bottlenecking a 4850 crossfire setup at resolutions above 1680x1050 in certain situations:

http://www.hardwarecanucks.com/forum...-review-5.html

so the answer is, yes your CPU will likely be holding back the 4850 crossfire setup, but depending on the resolution you play at (1680x1050 or less) it may be tolerable if you have to wait to upgrade your CPU. If you have motherboard that'll take it, I'd suggest a Phenom II X3 720BE for a cheap, significant gaming boost for that setup. Of course, Phenom II X4 940BE or higher quad core will give you an extra core to boot.

Good luck.

[Squirrel Meat]

I would say definetly. I just went from a 6000+ @ 3.3 to a PhenomII 720 @ 3.5 and the difference was HUGE. I game at 1680x1050. So Im assuming it would be a pretty big diff for you as well.

[drdoom]

I got a 1gig 4850. I am assuming over the next 6 months or so I should be able to get a second pretty cheap. I have a Biostar MB so I was going to get a 720BE and hopefully unlock the 4th core. If not then it is still a great CPU for cheap.