Hey Guys,

Was hoping to get a bit of help here. I recently bought a Radeon 3870 for my dell Dimension 4700 only to find that it was incompatible with my motherboard.

Here is a link to the card I bought on newegg:

newegg.com/Product/Product.aspx?Item=N82E16814125086

I was told that I could get a Nvidia 8600 GTS to work on my machine as well as a Radeon 3850.

My question is two fold:
Will both of these cards work on my machine?
Why would the radeon 3850 work but not the 3870?

Thanks for any and all help!!!

P.S.
I upgraded my computer bios to the latest one i could find (A10)

The only reason I can see that the Radeon 3870 is incompatible is because of its length. It is too long and seems to interfere with the RAM slots. If so, you would have the same problem with the 3850. The Nvidia 8600 is shorter and might fit.

So is the length of the card the problem?

No, that wasn't the problem.

The card fit just fine (was a bit snug) but when I turned on the PC, it would just beeping constantly and my screen stayed black (even though it was connected to my motherboard through rgb cables since i hadn't installed drivers for the video card yet)

A friend knowledgeable in computers told me that meant it was incompatible with the 3870.

I took the card out and the computer loaded up fine. I also put in my old video card and the computer also loaded up fine.

The 3870 requires an external power connector, likely a 6 pin PCI-E. Was that connected to the power supply?

no it wasn't. I just connected it straight to the motherboard, heh.

I only have the psu that the system came with, is it enough for the video card to work?

Does the 3850 have the same requirements?

If a bought a different psu, would the 3870 work?

The external power connectors on the graphics card are not optional things. It won't work without it connected. The 3850 is the same way, yes.

ATI recommends a 450W or greater power supply for the 3800 series Radeon cards. I think yours is a 305W. While Dell tends to under rate their power supplies, I think you would be better off with a new one.

Okay, thanks for the help!

Last two question, does the 8600 GTS have lower power requirements then the radeon 38xx series?

What's a good PSU to buy that will give me 500w or so and won't be too expensive? any particular brand?

THe 8600GTS still requires at least a good 400W.

Here's a 500W Antec Basiq. Only $60. Corsair, Thermaltake, and OCZ also make good PSU's.

That 305W PSU has 22A on the +12V rails. It will run an HD 3850 or an 8600GTS fine. You don't need a new PSU.

I see so the 3870 needs more energy then a 3850 which is why it didn't work but both need to be hooked up to the psu regardless. Did I get that right? =D

Thanks again to everyone who's helped. I'm more grateful then words can express!