Well.... werewolf, on that note. If he's playing older games who cares if the cpu is the bottleneck.... it will be bottlenecking at 60+ fps so as long as you're breaking that magic number of 60.... who cares
I just believe he would benefit more from an overclocked I7 and a 480 over 480 SLI with an overclocked Q9550. Very few games would properly utilise that much processing power.
You really thing the architecture move from a core 2 quad to an i7 (lets assume same clock speed, 3.8ghz, which is realistic) is going to provide even a noticeable improvement outside of video / audio encoding?
You guys way over-play the cpu. His 3.8ghz core 2 quad is probably running faster than any stock i7 920, or any stock amd quad-core.
You're all making it sound like adding another 480 will add 0-5% improvement. Almost no value, when clearly according to the graph posted on the first page it nets a 50-80% improvement with a moderately clocked i7. now take all those numbers, and scale them down for ..... lets be generous, 20% for a cpu bound game, and 0% for graphically bound games.
So these numbers are all made up.... say he's getting 30 fps in crysis at 1920x1080 at his quality settings on a 480...... throw in another 480 and you'll be probably getting 80% improvement. That puts you at 54fps. Now lets imagine he went with an i7 instead.... and we'll be generous and say Crysis is cpu bound.... which it isn't, but lets just go with it. Instead of 30 fps he'd now be getting 36 fps. So your upgrade path nets him almost nothing in poorly performing games....
what about "old" games like you've talked about. Lets look at unreal 3 for instance.... 150 fps sounds about right... maybe? So lets be realistic, it's cpu bound, there's no doubt. So at a 20% improvement going from a 3.8ghz c2q to an i7, he'd be at 180 fps if he just went with a cpu, and not another 480..... lets assume cpu bound games get no benefit from sli, absolutely none.... which is mostly true, in fact performance would be worse. Lets say 10% worse (made up). That puts him at 135 fps. So in this case sli actually hurt him. Guess what, who cares, it's still 100 + fps.
My point is "old" games won't benefit to any meaningful
degree with either upgrade. However, "new" games that are graphically bound 'nearly' double in performance with sli, but only receive a small increase with a cpu upgrade.
Unless you have outside motivation for moving to an i7, such as you do alot of work with any video editing software, CAD, whatever, then yes.... go with the cpu. But just looking at the money you'll spend and the performance increase you'll get alot more from sli.
If you think my numbers are off they may be. It's not unrealistic to only see a 50% performance increase with sli, or a 50% increase with a cpu.... but that 50% increase with a cpu is still in cpu bound games which are already going to be running very fast. While with sli the 50% increase happens in the worst performing games, possibly meaning the increase from 40 to 60 fps, "playable".
Also, this whole thing hinges on the fact that "old" games run well, and cpu bound games are "old" games.... which I think is almost always true. I have yet to see a cpu bound game with a 480 run under 40 fps.... aside from maybe an RTS, which honestly, that probably isn't an issue at all at 40 fps
what I'm saying is it doesn't even matter what he's playing now.... if you want to future-proof sli is the best way to spend that same amount of cash, no doubt about it. Games will get far more graphically intensive but only marginally more cpu intensive... and consider this, with DirectCompute its not unrealistic to offload more to the gpu, like physics, water, or even game AI.... if that gets utilized more with these dx11 titles coming out then you're going to definitely see more benefit from another gpu rather than cpu