What is the difference between Opteron and Xeon?

Opteron v/s Xeon

New here so I am not sure if this is the right index, but I am looking to get a new super-dooper machine to run Cadence under Linux and I am wondering what to get. This will be for analog circuit design (sim/layout/etc). I would be running Red Hat Enterprise, which Cadence seems to now run in 64-bit mode on both processors.

Is there a performance advantage of one v/s the other? Is one more of a pain to get (and keep) working? Is one more buggy under Cadence?

Also, if anyone has a recommendation for a good video card to put in this I would appreciate it. My main goal is to be able to do a lot of layout from home (dual 20" LCDs so a dual output card is needed, or two singles I guess). I use an Nvidia Quadro4 at work now but not sure if it is the best. But I also intend on doing some heavy duty sims sometimes, so I figure I will just get something to do it all.

Thanks a lot!

Re: Opteron v/s Xeon

I found that spice simulation is very sensitive to main memory latency. I use Sciencemark2.0 to compare to spice. There is a high correlation. For example an 2GHz Opteron w registered memory complete a spice in about 60% versus a 2GHz Dual Athlon. The Sciencemark gives similar values.

Re: Opteron v/s Xeon

In doing more reading and pricing, I guess there is not a firm answer to if Opteron or Xeon is better than like a dual core P4. So as far as processors go, what should I lean to for this? I know Dell has some good deals on servers and I have been happy with Dell in the past - but they dont do AMD. And Xeons seem to come at a significant price. I guess I am looking for the best bang-for-the-buck on a high ends server, but not nessesarily the top of the line (esp if the relative performance improvement is minimal).

Also - how much does 64bit buy you? I know Spectre and Virtuoso have 64bit versions. I imagine a lot of the improvement is "for the future", but does anyone have any % improvement numbers?

Opteron v/s Xeon

It doesn't matter if you get Xeon or Opteron, they are both very fast right now. But be sure to get lots of ram 2GB or 4GB and fast SCSI disks.