ok - here is my dilemma - I was just offered this video card for a song - so I thought why not - and bought it.
Have been trying for two days off and on to get it to work with either Collatz or Milkyway with ABSOLUTELY no luck getting either one of them to run - milkyway won't even acknowledge that it exists while Collatz gives me a server error.
Even tried the optimized apps route, upgrading the chipset, etc, etc, etc.
Anybody have ANY ideas about what I am doing wrong and how to put this card to work??

Pop onto the Milkyway or Seti forums & ask Chris S. He only runs ATI cards & can advise where the problems are.

Are your catalyst drivers up to date?

Thanks Sirius - I'll do that!
and as for the drivers - the VERY FIRST thing I ever do with new/used equipment is get the latest drives - but thanks Voice

You running windows or linux? and what version. does it work for a while and quit or does not work at all? Did some reading and the hd 3850 is a double precision card that likes the voltage set at stock settings of 1.214 volts, if over it does not like it. I found the last set of drivers from ati last month were not very good on my 5870, and went back to a older set of drivers and everything worked again. My two cents worth anyway. good luck

Running Windows XP Pro w/SP2 for now Philzie - so far running great but did have to go back to a slightly older set of drivers in order to get it working right. What can I say - the price was right and I don't mind fooling with things! Just finished playing with an nVidia GEForce GT 240 that was donated to the cause - it won't run Milkyway but will run Collatz!
Next I'm going to play with an Evga 8800 GTX KO ACS3!

Glad to hear you were able to get the card crunching!!!!!!!!!