BleepingComputer.com: Partial system upgrade

Ok, so right now my computer is pretty lame... actually, really lame.

Right now I have:

CPU: Pentium D 930 3.0 GHz
Mobo: Gigabyte EP45-UD3P
RAM: 4GB DDR2 @ 255MHz 4-4-4-12
Graphics: nVidia GeForce 9500GT
Windows 7 32-bit

This summer I hope to upgrade it to something a little more like this:

CPU: Core 2 Quad Q8400 2.66GHz
Mobo: Gigabyte EP45-UD3P
RAM: 4GB DDR2 @ 255MHz 4-4-4-12
Graphics: nVidia GeForce GTX 550 Ti (fermi)
Windows 7 32-bit

granted, it's not a huge upgrade, but what am I looking at as far as a performance boost? Would it be worth the $400+ to do this upgrade?

Probably a considerable boost, at least as far as CPU power. I have one of those 930 preslar cores, nice little chips for general computing and great for linux boxes-but theyre definetly not powerhorses by any means. That quad will probably easily be twice if not 3 times as powerful. That being said, the 775 socket is pretty ancient, (good socket but the technology is rather old) I think If I was to sink 400 dollars into a system, id want more then just a CPU and a low end video card-I think Id just save my dimes and go for a new system. Intels rather pricey, but you can get a decent AMD gaming rig for 7-800 pretty easy. Just my 2 cents though, that quad core and that video card will at least get you into the directx 11 generation with decent, though not outstanding performance.

Depending on current the power supply, a new one may be needed as well.

The CPU maybe a bottleneck when playing games.

I understand that you buy something and a week later it's outdated, but I just bought this motherboard like last March, so I think I'm going to have to stick with LGA775 for a little bit longer. But I guess, my biggest question is how much of a performance increase am I going to get upgrading my 9500 to the GTX?

I would say a lot when upgrading your graphics card to a new and better one.

I would say, youll get at least 2-3 times CPU performance upgrade, and probably a hefty graphics boost as well. It is older technology, but the 775 socket was solidly built and so is the core2quad design. I would saya core2quad would not bottleneck a 550 to much. Now, if we were talking a 585 or a SLI configuration maybe, but I dont see to much of a bottleneck there.

Is there any other graphics cards out there that would give me better performance for around the same price? I've always used nVidia, so I'm not sure if there are any ATI cards that would be really good too for around the $150 I can get the GTX for.

For $150 you can this AMD graphics card.

How would that one work compared to the 5850? Someone else told me that one would be comparable to the GTX460.

Lower performance than a 5850 even though its a generation 6 card(DX 11) and the 5850 is a gen 5 card(normally DX 10 but sapphire makes a DX11 5850)
You can normally tell perfomance by the 2nd and 3rd numbers, in this case the 2nd indicates its an 8 series which is > 7 series
Of all the cards mentioned 6790 is the weakest

The 550 Ti is slightly weaker than a 6790, but not by much. Both of those cards are considered low-end, whereas the 5850 falls in between the midrange 6850 and 6870 depending on the game. The XFX HD-685X-ZNFC Radeon HD 6850 1GB is a good card if you want a 6850, and a XFX HD-687A-ZNFC Radeon HD 6870 1GB if you want a 6870. I suggest at least a 500W PSU if you want either card, or a 750W if you want to use Crossfire. If you have the cash, go for the 5870. Your current motherboard will not allow for SLI, but Crossfire.