X2 hd4850 1gb vs. hd5850/6850????

So, I was looking at video cards, and I found that I can get two hd4850s on Newegg.com for less than $100!!!!!! Super exited, I started searching for a video card that compared against them that performed well. Well, I think I have come to a conclusion, they match a hd5850 stock clocks. So, I am on a budget build and thought that these two video cards would be great. Now, this is not a hd4850 x2 card, it is two hd4850s in CF. Would this match a hd5850 performance wise, how far could I OC those video cards, what temp do they reach, and will they last me a while performance wise?

You are on the right track there 4850 cross = 5850 performance wise BUT ... you might want to check if your PSU can "feed" these babies properly (since you were talking about this build as BUDGET build you might find yourself yourself in a weird situation where you would have to sink more money into the PSU rather then into the GPU)
Buying a 5850 and a 500W quality PSU might be the better deal here then buying a couple of 4850's and a 600 W PSU that is more expensive (and have to deal with the heat noise and troubles associated with crossfire setup... I know better since I have a crossfire setup )
Go for the new and simple - 5850 + 500W PSU

The reason I wanted the hd4850s is because I can snatch 'em both up for under $100 new. The PSU will handle it, it is a XFX 650w PSU. (Only $68.99 after rebate, so I could use it in the next build too) Thanks you guys, I think it is the hd4850s. I just hope nobody laughs at me for having old tech. To tell you the truth, when playing games, I don't need DX11. Is there an update to get DX11 on older cards though? I know you can do that with IGP card.

no you still have 1GB, RAM in SLI/CF is not added together like that. also, you have been talking about this "build" since the summer

This 4850 deal looks pretty good, but I'm concerned that the card won't fit in my computer case. My case manual specifically says it can't fit a card over 8.5"

Someone told me this xfx 4850 card was only 8.5" but when I go to the manufacturer site, it says the card is 9"
But on the manufacturer site, the picture is of a reference model, not xfx. Does anyone have this model card and can you confirm the actual length?

Thanks

Also, you could do surgery on your case and then put in the hd4850 for CHEAPER.

Will you ever fill up all of the hard drive cages??????? Probably not. So, barrow a saw of something and remove it. I would jump on this, even if I had to remove stuff. Man, dual hd4850s for only $94! DO WHAT YOU HAVE TO DO!!!!!!!!!!!

I will look for a way to make more space. A widget is a gadget or tool. I won't be getting 2 cards though since I have a mATX motherboard with only 1 PCIe slot. The most intensive game i plan to run is Crysis Warhead, and I think 1 card should still get 30 fps. Good enough for me.

Hopefully mu Corsair CX500 psu is up to the task. I've been hearing bad things about the Corsair builder series.