I am new to your forum and find myself needing some input on a graphics card purchase.
Gigabyte P35-DS3R (single PCIe and it is not 2.0)
Intel Q6600 (running at 3.0Ghz)
Geil Black Dragon DDR2 1066 memory (4x1GB)
Mushkin (original) 550 PS.
Main HD: Rapter-X 150GB
Storage HD: WD 1TB
Graphics cards: Sapphire HD 4890 or Sapphire 4850 x2
My question is, how important is PCIe 2.0? I purchased the 4890 on Ebay for $165 about 2 weeks ago. The card has been awesome. I gave my Asus 4850 to my brother and he asked me to find him another to run Crossfire on his DFI x38 board (Newegg $79). While looking Newegg.com had an openbox 4850 x2 for $165 + $8 shipping. I purchased it. I just installed it and ran multiple tests and both cards are testing an par with each other. Is my issue the PCIe 2.0? Which card should I keep and which should I sell? I would brake even if i sold the 4890 on Ebay. The 4850 x2 are going for about $200 to $220 on Ebay. The 4850 x2 is a very large card. My friend has a GTX285 and it is about 2 inches longer than that card.
The 4850x2 is a good card and you got it for an excellent price, its performance is on par with a HD5850 which costs roughly $320
So if your not bothered about DX11, then you might aswell enjoy the 4850x2's power.
Alternatively, as your brother is looking for more power, you could take back your 4850 that you gave him, give him the 4850x2 and then sell your current 4890 and the 4850 on ebay and buy a 58xx series card (I would stay clear of the 5830).