Cheap PC for gaming

Hello.

I'm building a new computer for myself. My current one is athlon 64 s939 radeon x800 agp. Like the title says it's mostly for playing games. I'm not planning to oveclock.

I'm buying (prices in euro):
phenom II X3 720 BE ~140
AM3 / DDR3 motherboard ~something cheap preferably
cheapest DDR3 RAM 1600MHz ~75
HDD + DVD drive ~again something cheap
Zalman ZM-500HP 500W power source ~50 (cheap and quiet)

The above is fairly certain but not set in stone. But here's the deal with the graphics card:

I could get a Radeon HD4850x2 for ~170. But it's said on the manufactrures homepage that it requires 650W power source. On the other hand, http://game.amd.com/us-en/crossfir [...] s.aspx?p=3 This website says that a 500W powersource is certified for 4870x2. I'm guessing 4850x2 won't require more power so my questions: Is this Coolermaster SilentPro 500 RS-500-AMBA-D3 (500w) somehow better than the cheap Zalman? Will this Zalman 500W good enough? I'd much prefer a quiet PSU and I would have to spend ~60 more if I needed a 650W PSU.

Though 4850x2 might be an overkill for this CPU. The alternative is to buy a single GPU HD4850 512 MB for ~100. I would save a total of ~120 and overall cost for my computer would be ~580.

For comparison:
Intel Core 2 Duo E8400 ~170
Intel Core 2 Quad ~170
Geforce GTX 260 192 SP ~150

Any feedback and advice is welcome. Thanks.

Don't risk blowing your PSU which can also take out your mainboard and or GPU with it. A 4850 X 2 isn't a cheap graphics system that you can't cut corners on the PSU side. It needs a meaty PSU.

I would go for either the Gigabyte or Asus board, they are both excellent. MSI boards are iffy. The 650TX is an excellent PSU option for a 4850X2, and the CPU shouldn't bottleneck that card, unless you play a highly threaded game like FSX or GTAIV. Most games will not use more than 3 cores, as demonstrated here:
http://www.tomshardware.com/review [...] ,2280.html

Thanks again for everyone who replied. I added up everything and came up with 773.4 euros ($1,077.85)

AMD Phenom II X3 720BE
GIGABYTE GA-MA790XT-UD4P
WD CAVIAR BLACK 640GB SATA2 7200RPM 32MB
Corsair CMPSU-650TXEU
Kingston HyperX DDR3 2GB 1600MHZ NON-ECC KHX12800D3/2G Edit: my mistake shortstuff, forgot to add x2
SAMSUNG SATA 22X DVDRW
SAPPHIRE TECHNOLOGY Radeon HD 4850 X2 - 1 Gt GDDR3 - PCI-Express 2.0

Edit: Not as cheap as I originally intended.

Like I edited to my post, I inteded to buy 4GB of memory. Would those CAS 7 timings make a difference? Considering my build isn't top of the line.

I would disagree here. From the benchmarks I have seen, faster ram or better timings do not translate into significantly higher fps or faster application performance.

The Phenom II CPU's respond very nicely to RAM speed increases.

http://www.extremetech.com/article [...] 564,00.asp

I stand by my statement, especially if the price is about the same.

That review had more games than the Toms reviews I read. Interesting. It seems you're right too. Atleast there is a jump in performance between DDR1333 and DDR1600. Thanks guys. I'll sleep on it and make decisions tomorrow.

I think you are correct that the platform does make a difference.
The Phenom ii x4 benchmarks, while limited, do indicate that it is sensitive to ram performance.

On the other hand, socket 775 does not seem to be very sensitive, showing 1-3% or so:
http://www.tomshardware.com/review [...] 07-15.html

I think the i7 platform memory controller is so good that ram speeds mean even less there.

What is important is to get enough ram for what you do.

The kingston ram is better, but not much. I don't think that AMD can use XMP, but the ram should work fine.