Here is the link to the specs for your mobo:http://www.msicomput...odel=RS480M2-IL
It is socket 939 and supports all the way up to the FX55. If you want to stay with AMD, I wouldn't upgrade the mobo unless you are planning on changing to socket AM2 as AMD will not be releasing socket 939 CPUs in the future. If you do decide to go with a socket AM2 mobo, then you will have to change the RAM as well since AM2 requires DDR2 RAM.
So, to make a long story short, if you intend to stay with AMD, then I would recommend only upgrading the processor to maybe the 3800+ (which can be found for a very good price now) and possible increasing RAM (you didn't state how much you currently have). You should see a fairly large change in speed by upgrading these two items.
Now, if you really want to upgrade, then I would suggest going with a Core 2 compatible mobo and a Core 2 6400 CPU. But now we're talking about spending some money and it doesn't sound like you're really looking at spending a load of cash.
Edited by kidnova, 23 October 2006 - 12:23 PM.