The Game Rundown: Finding CPU/GPU Bottlenecks, Part 1

Features
By Tino Kreiss
published

Wondering if your favorite game wants more CPU or GPU muscle? We tested 20 different titles using a GeForce GTX 460 and a Core i5 processor (one of our favorite configs) in order to figure out where a solid mainstream machine gets hung up.

Bioshock 2

Bioshock 2 is also based on the Unreal engine, and it responds to multi-core processors and overclocking. A single-core CPU will slightly bottleneck the graphics card, so, ideally, you want two or four cores to fully shift the burden onto this graphics card. The performance increase between these three different core scenarios is so small, however, that an upgrade is rather pointless.

The graphics memory numbers here are interesting. Bioshock 2 only uses 430 MB with a single-core CPU, but 735 MB with a dual- or quad-core CPU. Whether the 10% performance increase comes from the second core or from the optimized use of resources is hard to say. Most likely, it's a combination.

When it comes to upgrades, consider a CPU with at least two cores or you might waste up to 10% of the graphics card's potential performance--and that's on a GeForce GTX 460. A higher-end GPU will be even more dependent on a capable processor.

Tino Kreiss
98 Comments Comment from the forums
  • adonn78
    Its True GTA4 can use 1.68GB of Video RAM at 1920x1200. And up to 1.8GB at higher res. The game can get pretty choppy unless you got a 2GB video card and a quad core. They even fixed the shadows so that they use less VRAM but it still craves GPU memory.
    Reply
  • karma831
    It was nice to see CPU and GPU load percentages.
    Reply
  • experimentxx
    Best read for a pc gamer..
    Reply
  • Tamz_msc
    good article, cant wait for part 2!
    Reply
  • It would have nice to see what is making my favorite game Company Of Heroes be bottle-necked. I have a GTX 480 and an AMD 955@3.4 GHz and i still get laggy frame rates when there is heavy action and weather. Settings all maxed out on dx10 at 1400x900. I heard that the hard drive is what it makes it lag...
    Reply
  • NuclearShadow
    GTA IV is one of the few games that I could actually see the performance difference with my own eyes when I was on my i7 920 rig with 6 GB of ram and a 4890 when I overclocked. That was a pretty damn good rig (and still is)

    Something I was amazed by in this article is that games like MW2 give pretty good frame rates when running on a single core. I would have never expected such. 59.1 fps would certainly be acceptable for game-play. Also its a shame to see that so many modern titles really don't take that much advantage having so many cores. It's been more than enough time for this to be adjusted and yet the performance difference in most titles seems minimal between 2 and 4 cores. (or in some cases even 1 core) At this rate everyone is going to commonly have 12 core CPU's and most games will still only truly utilize two.
    Reply
  • baracubra
    OMG this is exactly the article I've been craving since my upgrade from 8800GT SLI to GTX 470.
    I have a Q6600 @ 3.6 but in BF:BC2 I only get around 40% GPU load and 80% CPU. However, my frame rates are in-line with those in this article...

    Anyway I really look forward to the next article!!!!
    Reply
  • Even though its an older game, i would really like to see crysis in part 2.
    Reply
  • skora
    This needs to be a staple and have a section in the charts! This is by far one of the most useful articles I've read in a long time and really get down to what matters based on title. Great job TK!!!!!!!!!!!!

    Chris, make a section in the charts for this and keep them updated please!!!!!
    Reply
  • archange
    You need a better GPU. With the GTX 460 768 MB, the bottleneck shifts strongly towards the GPU, making a comparison between dual/quad cores and 3 to 4 GHz quite pointless.

    This is best showcased by the introduction of the HD 5870 in single and crossfire mode - in the last chart - you can really see FPS picking up.
    Reply