How to determine whether to upgrade videocard or processor?

As sort of a follow up question to this post by com2006: http://www.gamespot.com/pages/forums/show_msgs.php?topic_id=26619989

When newer games are starting to crawl at framerates lower than 30fps...

What factors determine whether it's time to upgrade my videocard vs my processor?

aren't there any general rules, or indications that show whether it would be better to upgrade one before the other?

i've already made all my upgrades but i'm just curious.

right now i have a Geforce 8600GT 512mb DDR2, and a Core 2 Duo E7200 2.53Ghz...onch

That is a great CPU, but the GPU falls a mile behind.

Even un-overclocked that CPU is a load faster than the GPU.

Thanks. I like how it's 45nm. Anyway, i was just curious, so that i'd know what to upgrade first in the future.

Set the game at a low resolution (eg. 800*600), run a benchmark to measure the fps

Increase the resolution (eg. 1024*768), run the same benchmark again

Do you get lower performance the second time? Your GPU is the limiting factor.

Do you get about the same perfromance? The CPU is holding you back.

Set the game at a low resolution (eg. 800*600), run a benchmark to measure the fps

Increase the resolution (eg. 1024*768), run the same benchmark again

Do you get lower performance the second time? Your GPU is the limiting factor.

Do you get about the same perfromance? The CPU is holding you back.

Gog

Im trying that as soon as I get home, I think my cpu is holding me back some. I have a phenom 8450 paired with a 9800 gtx+ superclocked edition.

Set the game at a low resolution (eg. 800*600), run a benchmark to measure the fps

Increase the resolution (eg. 1024*768), run the same benchmark again

Do you get lower performance the second time? Your GPU is the limiting factor.

Do you get about the same perfromance? The CPU is holding you back.

Gog

If you do this all CPU will act like a bottle neck at some point,on a low resolution the GPU has little to render, at high resolution the GPU has alot to render, and as long as the CPU can handle more FPS than the GPU at the resolution you play at there is no bottle neck from the CPU.

And who play at 1024*768 today? mostly people play abowe 1280*1024 or even abowe 1600*1200, id like to see a game where the CPU holding the fps down under that resolution.

Set the game at a low resolution (eg. 800*600), run a benchmark to measure the fps

Increase the resolution (eg. 1024*768), run the same benchmark again

Do you get lower performance the second time? Your GPU is the limiting factor.

Do you get about the same perfromance? The CPU is holding you back.

Gog

Thanks, i think this is pretty much what i needed.

BTW after much testing with my 8600GT, i discovered that it's quite hard to get playable framerates above 1024x768 for current gen games. So i set my ceiling to 1024x768. And in games like COD2, 1024 is playable but i still set it to 800x600 because that gets it up to about 50 to 60fps.

right now i have a Geforce 8600GT 512mb DDR2, and a Core 2 Duo E7200 2.53Ghz...onch

the gpu is the bottleneck