I would say, before, since you can't do it after if the CPU isn't supported by the currently installed bios, which it might be. I wouldn't take the change though unless you can verify that your currently installed version does support it, elsewhere. There are usually forum posts verification's on various sites where members do verify they've used specific processors on specific bios versions.
For yours, I'd upgrade it first, and this forum entry seems to indicate verification of compatibility all the way up to Intel Core 2 Duo T9900
Sorry I did not realize my whole statement did not get included when I copy/pasted it. My question was/is will my BIOS need to be upgraded and if so then do I do that prior to changing the CPU or after?
I would say, before, since you can't do it after if the CPU isn't supported by the currently installed bios, which it might be. I wouldn't take the change though unless you can verify that your currently installed version does support it, elsewhere. There are usually forum posts verification's on various sites where members do verify they've used specific processors on specific bios versions.
For yours, I'd upgrade it first, and this forum entry seems to indicate verification of compatibility all the way up to Intel Core 2 Duo T9900