Upgrading advice needed

[Xythoces]

To get this out of the way: specs
Abit Fatality FP-IN9
Intel Core 2 quad Q6600 (4x 2.4GHz) stock cooling
2x XFX Nvidia 8500gt Graphics Cards (x8 x8)
2x Patriot 1024MB ddr2-800 running at 5-5-5-15
Samsung 500gb harddrive (sata)
no overclocking

Now then, a while back, I bought Overlord. I've noticed two things: One, good game, and two, I lag horribly at the highest settings.

Basically, how do I find any bottlenecks which might impede performance, and if there are any obvious problems with my setup, how can they be solved (cheaply)?

And another thing, while on the hunt for a better Mobo, I ran across a few articles stating that there is no obvious performance boost between full x16 sli and x8 sli. It has also been a long, arduous trudge to find a mobo under $200 that offers double x16 sli. Is it worth it?

 

[Whiffen]

I'd say those graphic cards are holding you back. You can try to sell them and get a P5k mobo and 8800GT. Or just get the 8800GT and wait to upgrade your mobo. Both of the cards you have aren't very strong, and SLi with weak cards doesn't do much good.

 

[Rage_3K_Moiz]

No, not now at least. Even the 8800GTX does not completely saturate the PCI-E x16 bandwidth, so I hardly think the 8500GT would. It wouldn't make any difference if you get a board with x8+x8 SLI.

The 8500GT SLI setup you have gives you roughly the amount of pixel-crunching power wielded by the 8600GT, which isn't much to run Overlord on the highest settings possible IMO. However, if you suspect the video card is not the problem, try turning v-sync off and patching the game with the latest patch. Also, try lowering graphics settings to see if the problem still persists. If it doesn't you'd need a new graphics card.

 

[Xythoces]

Whiffin... the P5K, so far as I know, only supports crossfire and you want me to get that and sli cards?

On another note, I think it is a graphics issue, but I'm not sure. The real clincher for framerate is the soil cover option(grass, bushes etc.). The next worst are the bloom, distortion (I think it means shaders...) and then texture quality. With all of the above at the lowest setting, I can turn antialiasing on to x8 with no loss in quality.

I suppose that means that it's a graphics issue ....

I just wanna know I'm right before I spend money on something that won't help.

Also, I was looking at The EVGA 750i FTW mobo...

 

[Rage_3K_Moiz]

You'd see a large boost with a new powerful graphics card then, something like this. Pairing it with your current mobo will give you a significant performance boost in any game. You wouldn't need to change your mobo either.
However, you might need a new PSU, if your current one doesn't have at least 28A on the +12V rails combined.

 

[SNGX1275]

For a bit cheaper and slightly less performance you can get this, a 9600GT which as of this post comes out to $124.99 with MIR, $144.99 before. And you wouldn't need 2 of them.