Just like the PhysX post i wrote, i've been seeing some really weird (and bad) advice for people go buy quad core (and above) CPU's for gaming without knowing what people are talking about, just because google/wiki etc has said a game is 'multi-threaded' When a game is multi threaded, it doesnt magically mean it uses all cores to their maximum, removing bottlenecks. thats magic, not multi-threading. Let me give you as simple an example as i can: Game A has one thread, with AI, sound, video, physics, and networking all in one thread. Game A gets a patch! woo! its now multi-threaded with physics and networking on threads 2 and 3. This game is now multithreaded. it can use three cores! awesome! What people fail to realise is that just because its multi threaded, doesnt mean those two extra threads need all that much power - they could easily be done in one thread, in one core, with room to spare... while the other thread (with AI, graphics and audio all bundled together) is bottlenecked, running out of CPU power. Multithreading means each task can have its own thread, not that each task can split itself even further and run on multiple cores. Even if your game has 8 threads, if just one thread needs more performance than one core can provide, the extra power on the other cores is wasted - that ONE thread, on ONE core holds you back making you CPU limited even if your CPU isnt at 100% usage. The moral here, is that just because someone tells you a game is multithreaded, doesnt mean a slower CPU with more cores is better overall. An example (theoretical, but reality isnt too far off) CPU A: dual core, 3GHz CPU B: Quad core, 2.4Ghz for the sake of this example, lets assume the quad core has exactly double the amount of cache as the dual core and they are the same basic design (think E6600 + Q6600, but at diff clocks) Lets say the example game has four threads. video, audio, networking, physics. On the dual core, core 1 is maxed out running the physics, with core 2 running at 80-90% running the other three. Lets go to the quad core: Yes, audio video and networking now have their own threads. none of them are at risk of bottlenecking... but the physics thread now has 600Mhz less power, meaning that despite you having twice as many cores, you now have LESS power for that one critical thread that was holding you back before. In this case, going quad was a downgrade because it had less performance per-core, than the dual. jumping back to real world examples, look at this: Intel E8500 has 6MB of cache between 2 cores (3.16GHz) Intel Q9400 has 4MB of cache between 4 cores (2.66GHz) I think my above example and the CPU comparison there (they're roughly similar prices) gives it away. Just because a game is multithreaded, doesnt mean more, slower cores helps - only upgrade to more cores if each core is the same speed or faster than what you already have. (this may need more edits as i go along, i always screw something up) Part 2: how to tell if you're CPU limited in a game #1 task manager. If any one of those bars maxes out during a game, then you're limited on one core - even if it was just briefly, you were limited, briefly. Some people will see that 100% on various cores over time and assume that a game is multi-threaded, but the truth is that windows throws your threads randomly between cores. even a single threaded game gets tossed around between cores for no apparent reason, so just look for ANY core being maxed at any time. 2. MSI afterburner I use afterburner combined with its OSD and Vsync, to give me an FPS reading and a GPU usage reading. Very simple logic here: if my game cannot give me 60FPS solid, yet my GPU is not at 100% usage... then my CPU (or something else, perhaps network lag in an MP game) is holding me back. play an SP game, check FPS vs GPU usage and you get an easy answer. In the above image, its very clear that neither my CPU nor my GPU is holding me back (at least, at this point in the game) since i'm getting a smooth 60FPS and my GPU is nowhere near its limit.