Just upgraded from a P4 2.4ghz
2gig RAM DDR
Sparkle Geforce 6800GT 256mb

Did it because I wanted to play the last few missions in Oblivion with smooth gfx, play the wonderful Armed ASsault with all detail and Supreme Commander which I know needs beefy hardware.

But:

My new Core 2 duo 2.4ghz
1024 RAM PC6400 DDR2
Palit Geforce 7300GT 256mb 128bit version.

This is the problem:
It plays Oblivion (with the same detail levels with the previous rig) just the same, with no increase in performance. Armed assault has'nt improved whatsoever. I have up to date nvidia drivers as well.

I was just wondering, have I bottlenecked the machine with the 7300GT? I don't see how, as all the factors point to a faster machine! Help?

PS: I have read that the only games out there at the moment that use multithreading are Oblivion!?!? Supreme Commander and Call of Duty 2.

Any advice!!?!
Ta.

I personally am not surprised. Games are graphics intensive more than CPU intensive. Your graphics horse power went up a little bit, but you went to providing your single CPU 2Gb to play with, down to giving each single core only 512Mb. You are choking yourself - assuming everything else is the same and you are not infested with malware or heat issues. Double your RAM.