This real estate mess has got all of my extra cash frozen so I am trying to make do with three year old technology.
I hear you there.
Your mainboard is very similar to mine with nearly the same bios options.
If you really need to stick with the current PC, try to lay your hands on a 3700+ San Diego CPU or a 4400+ X2 Toledo dual core, (ebay?).
The Sandy will overclock on your mobo close to 2.8ghz without any cooling required.
Even if you do find it needs a cooler, the coolers available will usually have mounting parts for socket 939 and socket LGA775 for Intel based cpu's, so the cooler can be migrated to a new system later.
Overclocked, the Sandy is a huge upgrade for you. I used to have a 3500+ and it was lame next to the 3700+, big difference. The 4400+ is basicly two Sandy's under one hood, but they don't go quite as fast.
You can buy a whizbang Video card too, it can be moved into the next PC if you want to do that.
There are much better cards out there than the 8800GT and they are pretty cheap, but they may be bottlenecked somewhat by the rest of your current hardware.
So yeah, overclock a 3700+ and get a cheap 8800GT perhaps, (or GTX if you get one cheap) and this would be a relatively inexpensive interim solution.
The only problem I can see is if you have a weak PSU, then that may be overcome by buying a GOOD psu that you could use in the next rig as well.
The graphics card choice is your's, personally I'd wait until building the new system before I spent big on a video card. The 8800GT or similar (9800gt - same card, new name?) is pretty cheap now and it will be a vast improvement over your present card. I ran a 6600GT, then a o/clocked 7900GS, and now an 8800GT. Big steps.
At least you do have the option of a cheapish upgrade without dumping too much money into an old system, You could still use the newer components in a new rig later on, except for the CPU, but you should be able to find a 3700+ Sandy really cheap now.
Make sure the 3700+ is socket 939 if you get one.
Compatible models are:
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