L4D SC!

So are there any "benchmarks" for L4D when going from just playing the game normally and loading up splitscreen?

Iv got

AMD 6000+ @ 3259MHZ
4GB G.Skill
260 GTX @ 656MHZ

1680x1050 22" LG LCD or 1920x1080 52" LG Scarlet LCD

And depending on this deal im about to get on some gear for my secondary lan pc i may only have one capable system...so you guys think it will handle pretty well at the above res's? the gfx card shouldn't have a problem but will the proc kill it?

I don't mind lowering settings if need be...

That system is more than fine. My secandary system is this:

Pentium D820 2.8Ghz (Yes, that is the old crappy pre-C2D Pentium D CPU)
3GB DDR 5400
8800GTS 340MB
w/Vista 32bit and this system can play L4D split screen at 1080p with mostly high settings. The only thing I've really had to tone down was to disable AA, which at 1080p on a 46 LCD isn't even that big a deal. The game looks very good and my son and his buddy play split screen on it all the time. The system in my sig (expect now with a 4870) plays L4D with everything maxed at 1680x1050 without a hiccup and split screen doesn't even make a difference as far as performance. Solid 60fps (w/VSync on)