just a quick question. When i look at newegg, how come there are some card like this one
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130416
even more expensive than this one
http://www.newegg.com/Product/Product.aspx?Item=N82E16814143179
would these two be a good combination for my computer
http://www.newegg.com/Product/Product.aspx?Item=N82E16817101021 (this power supply have the 6pin connections right? (just in case i want to upgrade to something like the 4870 later))
http://www.newegg.com/Product/Product.aspx?Item=N82E16814143179
EVGA 512-P3-N879-AR GeForce 9800 GTX+ 512MB @ $174.99, that is a very very very bad deal, its way overpriced do not buy that.
BFG Tech BFGE981024GTXPOCE GeForce 9800 GTX+ 1GB @ $139.99 is a good deal, I would recommend you buy this out of the two GPUs that you posted
However.
You may be better off spending ÂŁ10 more and purchasing the, SPARKLE SXS2501024D3-NM GeForce GTS 250 1GB @ $149.99, although it is derived from the 9800 series it is clocked higher by default so performance is better, around 5-20% better
http://www.newegg.com/Product/Product.aspx?Item=N82E16814187069
I think you should also look into the HIS Hightech H485FN1GP Radeon HD 4850 1GB @ $158.99, otherwise get the GTS250 1GB for $149.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161275
Also.
Forget about the ATI 4870, keep that card out your head. The 4870 (DDR4/512MB) isn't much faster than the GTS250 1GB or 9800 GTX+ 1GB or 1 GB ATI 4850, a few frame rate difference separates these cards at best(5-15 FPS). Secondly as it was said previously the 4870 will not perform at 50% of its intended speed with your slow processor. I'm even confused if you'll even see 50% of the performance on the GTS250 1GB or 9800GTX+ or ATI 4850, but in either event it is a HUGE upgrade from your current 8400 GS is not really a gaming GPU anyways.
So to summarise:
1.) Get either the ATI 4850 1 GB @ $158.99 or GTS250 1 GB @ $149.99
2.) Your CPU is weak and you will not see maximum performance on ANY of today’s GPUs
3.) ATI 4870 will be severely bottlenecked too and isn't massively faster, so forget about it!
4.) Contemplate upgrading your processor if you want high end GPUs
5.) Buy PSUs recommended by fellow thread posters
PS. That PSU looks like junk, I'd recommend buying on of the PSUs suggested to previously.
Edit:
Do not touch the 512 MB version of the GTS250 as they are 9800 GTX+ in a different box, either get the 1 GB version of the GTS250 or the ATI 4850 (preferably the 1 GB 4850)
Edit 2:
But speaking sideways I stick by my frist recommendation, your CPU is best suited towards the ATI 4830, the money saved can be put towards CPU such as the E5200 which you can overclock like crazy, or a E7xxx/8xxx series if overclocking isn't your thing.
The ATI 4830 @ $89.99---->
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102822
and put the financial savings towards... Intel Core 2 Duo E7400 Wolfdale 2.8GHz @ $119
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115206&Tpk=E7400