Try uping the cpu voltage a little, it might make 225 reachable. Tweek the cpu voltage very slowly, this is what will bring your temp up quickly. Make sure your ram isn't 1:1.
I honestly don't think its your processor thats the problem, I have a 3000+ 1.8 amd64, and the thing hauls a**. Try getting rid of some of your services, also check your Virtual memory settings. Your comp should be doing better then that.
Start/run/msconfig will allow you to see the programs that run at start up.
Go
here to figure out what services you can lose. Make sure you read what your disabling to make sure that you really don't need it, because it sucks trying to find the problem when you disabled like 20 services.
Run an anti spyware program like ad-aware from
lavasoft and an anti-virus progy.
My virtual memory file starts at 1 gb(1024 mb), and allowed upto 4gb(4096mb) on its own deticated partition. Defrag your hd before you up your vm settings, if you don't you will get a fragmented swap file, which will also slow you down. If your vm file isn't going to be on a deticated partition then I would make it start at 2gigs(2048mb).
Also make sure all your drivers are the latest versions from the manufacturers, with the exception of your video card use Nvidias drivers for that.