Worthwhile upgrade?

[TJM]

Hi folks. I'm planning to build a new PC late next year and want an upgrade to hold me over until then. My current spec is this:

8800GTS 320MB DDR3
Intel Core 2 DUO E6750 2.66GHz @ 3.2GHz
4GB DDR2 (2x2048MB) PC2-6400
eVGA NF650i Ultra
Vista 64

I figure more RAM won't really help, but I was considering getting these:

Powercolor ATI Radeon HD 4870 1024MB
Intel Core 2 Duo E8600 3.33GHz (Guaranteed to run at 4.00GHZ)

Would I get a performance increase worth the £400? I'm sure the 4870 is far superior to the 8800 GTS, but I'm not so sure about the CPU - is there a big difference between 3.2 and 4.0? If not, I'll just get the 4870.

Cheers

 

[TJM]

I have, but it becomes unstable as soon as I go over 3.2GHz. Weird problems crop up, like watching a video for more than an hour freezing the system, even though it can run the various Orthos tests for several hours at 3.6GHz with a full load temp of about 65 without a problem.

 

[TJM]

As you are running 4GB of ram it soemtimes helps to increase the NB voltage a notch or two.

I had this problem when I was using 2GB, but I can't change the NB voltage in BIOS anyway. I guess EVGA saved that small option for the more expensive mobos.

Have you tried increasing the vcore another notch or two to get that cpu fully stable?

Ya, had it as high as I thought was safe (1.48v) and it still happened.

Thanks for the advice, I'll just get the 4870 then.