Would my CPU be fast enough for a 4870?

Well me too I have the same problem as you'
I'll receive my 4870 in some days and I'm figuring out if my Pentium D 945 @ 3.4GHz may bottleneck the 4870. I'll like to play Crysis at high sepcs will all the eye candy features.

I'm scared that the CPU will blow away my enthusiasm.
Well I'm planning to have a C2D 8400 or the Q9450 to replace the CPU.
I'm also having an Asus P5Q-E who has the PCI-E 2.0.

Both cpus will be a slow down, but youll both see nice returns. @ OP, your res and that gpu is your slowdowns, much moreso than the cpu.

I had a Pentium D 945 @ 3.4ghz with a Sapphire 4850. COD4 lagged frequently, but sometimes ran good. However, GRID ran terrible. Even with the resolution at 1024x768 with all settings at low, GRID ran below 10fps (cpu sensitive game?).
The D945 needs good cooling, but even then, it can't keep up with today's cards.
I got an E8400, all my problems were solved. Crysis, Grid and COD4 all run amazing now.

Thanks for the input Yeah I know that the GPU is the slower part but I just wanted to know if the CPU would be slower, Becuase I dont want to upgrade the CPU till the 45nm denebs come out. Now for the res. of 1920x1200 would one 4870 be good enough? Because my PSU only has 2 6pin plug(One of them is a 6+2 pin) so if I get a 4870 then thats all i get. But I can run a 4870x2 with the PSU(Which is 700w...48amps on the 12v over 4 rails.)

Also I found this card on sale... With a free game Grid.

I think thats and killer price...Also free shipping.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

19x12 is perfect for the 4870. Thats where it reigns

mmmm likely not, the oc'd 3870 might not be the culprit if like he said hes playing without AA. That could mean on average 30-50% more fps than with AA on. The benchmarks ive seen show the 3800 series being enough for 1900x1200 without AA in all but crysis. The phenom you have just doesnt have the horse power, and is holding you back. Ive got a 4870 and i feel my e6300 oc'd to 2.8ghz (stock speed 1.86ghz) is holding me back. I thought that with my 7900gt, at least in Crysis anyway.

Get an 8400 or wait for the 45nm 12mb L2 cache intel quads to get cheaper, and pair it with a nice p45 mobo. Or take a look over at Anandtech.com at what the new sb750 southbridge does to phenom overclocking and get a new am2+ mobo (with the newer southbridge of course). You could get 3.0ghz out of your b2 stepping phenom, and stick a 45nm phenom in when they come at the end of this year. In gaming should be around 10% faster clock-for-clock then the 65nm Phenoms, and oc much better. Thats if u wanna stick with an all AMD setup. If your wondering, i can tell you first hand the 4870 is a wonderful card. Crysis all on dx9 high with 2xaa and paralax occlusion mapping enabled through the shaders cvar group, average 30-35fps through the entire game. Im not a huge fan of crysis but it does show how powerful the card actually is.

/rant

I Thought the CPU would be the case...but Im going to did the 4870 and that will had me over till the 45nm phenoms come out. I was looking at the new sb750 but I just build my rig and I have a really good mobo MSI K9A2 with the 4 PCIe slots. I have a Cooler master hyper X2 heatsink for the cpu and I keeps it cool but the 9600be I have wont go over 2.4 It runs on 2.4 oc but its unstable after about 2 hours.

Thanks for the input.