first time in AMD world, which to choose

The opteron 248 is socket940 which is not as popular as socket939, i would not recommend the 3800+ , of those three choices i would probably recommend the X2 3800+ which is dual core which will do you good in the near future when more games/apps start taking advantage of dual core chips

i agree with stalion, the x2 is the way of the future... and will overclock pretty decently...

Personally i would go for 3700+, it's a hell of a lot cheaper and performs like a 3800+, and it oc's well too. But if you were to spend that much for a 3800+ i would go for a 3800+ X2 since it's only a bit more

get the x2 games are starting to jump on the dual core badn wagon , E.G: UT2007

with the x2 3800, should i expect the same performance i have with my actual hardware?? i'm planning to buy a motherboard MSI K8N NEO4 platinum to go with it

If you want dual core, the 3800 X2 is a pretty good but on a budget. The 4400 Toledo is the probably the "best buy" X2, for an overclocker anyway, but I'm guessing thats out of your budget. As it has been said, a 2xx Opteron is a socket940 CPU, which you don't want. The socket939 Opterons are 1xx, and they will be labeled as 939 because there are 1 series 940 CPUs as well.

For single core the best CPU is the 3700 San Diego. It has 1MB L2 cache (vs 512k on the 3800 Venice) and the current crop seem to overclock very well.

the 3800+ x2 will be comparable, if not faster by a bit.

Get the x2 3800

Here is the list and options on the Optys. BTW the Opty X2 have 2x 1024 cache, only the 4400+ and 4800+ have 2x1024 cache, the others have 2x 512.
http://encyclopedia.thefreedictionar...icroprocessors