8800 GTS 640...when does the CPU become the bottleneck?

[ctk1981]

At what point does the CPU bottleneck the GPU mentioned above? I have a BFG tech 8800GTS 640MB OC2 to be specific.

Here is my current setup:

Windows XP 64 bit
3800+ overclocked to 2.5Ghz
500mhz DDR 1
Audigy 2 ZS
Asus A8n-SLI premium


This old setup had two eVGA 7800GT (factory overclocked) in SLI configuration. It played most of my games quite well, but not good enough on my 24" WS LCD. In 3dmark06 is scored around 7100 or so.

The new card in this same machine with newer drivers scored around 8400. Played a couple games at higher resolution and some AA/AF and it seems to handle them pretty good. At this point though I'm just wondering how much of a bottleneck this current CPU is.

Parts that I will be upgrading to:

Asus P5K Deluxe
Intel E6750 (overclocked too.....well, whatever it does?)
Crucial 1066mhz DDR2
Windows XP 64 bit will remain on the system, clean install of course.

Any idea what kind of performance increase I may see? I realize that this is quite a jump from an dated socket 939 system.....stuff just got real cheap and hard to pass up, regardless of what new technology comes out this *should* be a good upgrade for now.

 

[lavaheadache]

At the high resolution of the 24 incher I doubt you'll be seeing much of a cpu bottleneck. Chances are that you see that your minumums went up by a few fps and that your maximums went up significantly, meaning your averages are going to go up By 5-10% percent or so. That is about what I experienced going from an x2 4200 to a c2d e6600 with the 8800 GTX on the 24 incher. Hope this helps



Also you have to remember that 3dmark 06 isn't testing at the native resolution. I bet if you test in 3dmark 06 at 1920x1200 the gap is much larger than 1300 marks.

 

[Gumby84]

http://www.firingsquad.com/har...x_gts_amd_cpu_scaling/

 

[ctk1981]

Thanks guys. I'm not all that concerned about 3dmark really, it was just something I could compare against real quick and put a number to it. When I seen the "marginal" gap it made me wonder if the processor was holding me back some. I'm sure the new setup will bring more performance in, all around not just in gaming.

 

[chizow]

That Firing Squad review uses some pretty low resolutions, unfortunately.

I'd say it also depends a lot on the game you plan to play. I know that some games do scale extremely well with faster CPUs/more cores even at higher resolutions where the GPU would normally be the bottleneck. I believe Supreme Commander is one of those examples, where you can see a significant improvement to frame rates going from single core > dual core > overclocked dual core > quad core etc. with the same high resolution and settings.

I've also seen a nice improvement in LOTRO under certain conditions with Overclocking. Had to run stock speeds for a while trying to nail down some problems with Vista/4GB/X-Fi and saw a very nice improvement once I was able to OC back to 3GHz+. About 10 frames during Raids/PvP, which is a pretty significant improvement from frame rates that could drop into the teens at 1920x1200.

 

[napes22]

Originally posted by: Gumby84
http://www.firingsquad.com/har...x_gts_amd_cpu_scaling/

The article basically shows that the 8800 GTX is leaps and bounds ahead of the 1950XT. Are in game results that noticable? I have an x1800XT with an X2 4200+.

 

[jeffw2767602]

instead of an e6750 get a g0 q6600. it will run circles around the e6750 for about $70 more.
i have a q6600 and 8800gts 640 and i get almost 12500 on 3dmark.
my q6600 is at 3.6GHz and my 8800 is at 620/2000

 

[ctk1981]

Sorry, its a done deal. The parts are here sitting next to the desk ready to be slapped in. 70 dollars normally wouldnt be a whole lot to me, but with a newborn here and the fiance off from work 70 dollars is a BIG price difference. I'm lucky I even talked her into letting me get any of the parts for the upgrade. Sold off the motherboard/processor/one 7800GT to my father who needs an upgrade worse than I do. He is running a P4 2.66ghz oC to 3.01ghz with 512MB of ram. That thing seems like it crawls anytime I have to come over and work on it. That and the hd tied to the system is a Ulta ata 66 20GB.....have a nice SATA 160GB for him when I do the upgrade, left over parts.

 

[Capitalizt]

I would like an answer to a slightly different question..

Is there a general rule as to what CPU speed will cause the 8800 to be the bottleneck?

I'm wondering what the "optimium" CPU speed be to get the most out of a (slightly overclocked) 8800GTS. This would be useful to know for those trying to keep their systems cool. There's no need for a crazy 4ghz overclock if you can "max out" the card's potential with a lower CPU clock/voltage.

It would be nice if someone could test to see at what point the extra CPU speed doesn't = a big performance increase in gaming.

 

[deadseasquirrel]

Capitalizt, many websites test this exact situation. What you'll find out is simply that "it depends". Depends on what, you ask? It depends on the video card you're using, the CPU speed, the resolution and settings you are testing with, and the exact game you're testing.

Typically, at resolutions at/below 1280x1024, faster CPU speeds can give more fps in just about *any* game. As you increase resolutions, that speed increase matters less and less (again, depending on the game... which we'll get to in a moment) to the point where a 4ghz C2D won't show any fps benefit over a 2.5ghz A64 simply because the GPU is being stressed and not the CPU.

There are some games, however, that don't fit that scenario. One of the most recent is Supreme Commander. But just about any RTS game will show similar results. FPS games are usually the opposite. But that trend could shift here in the near future as games begin to take more advantage of multi-core CPUs. So we may see a 2.4ghz C2Q perform better than a 4ghz C2D because of AI or physics solely using their own cores.

So, to answer your specific question about your GTS, I would have to know what games you play, what CPU you have, and what resolution you play at. Only then can we come up with how important CPU speed is for getting the most out of your GPU.

 

[superbooga]

Originally posted by: Capitalizt
I would like an answer to a slightly different question..

Is there a general rule as to what CPU speed will cause the 8800 to be the bottleneck?

I'm wondering what the "optimium" CPU speed be to get the most out of a (slightly overclocked) 8800GTS. This would be useful to know for those trying to keep their systems cool. There's no need for a crazy 4ghz overclock if you can "max out" the card's potential with a lower CPU clock/voltage.

It would be nice if someone could test to see at what point the extra CPU speed doesn't = a big performance increase in gaming.

It really depends on the game.

If you think about it, newer games place a lot of stress on both the CPU and GPU. However, GPUs become obsolete much quicker. Thus, newer games will almost always be very GPU-limited.

A high end card like the 8800gts has absolutely no problems running older games, so for older games it's going to be CPU limited. However, older games have lower CPU requirements as well, and even a 2.0GHz AMD64 can put up really good frame rates.

So for older games, the 8800gts will definitely be CPU-limited, but it won't matter anyways. For newer games, the more appropriate question would be, how fast of a CPU do I need to run the game smoothly, regardless of the video card? In that case, I think a 2.0 - 2.4 GHz Core 2 Duo is more than enough.