SCREEN STUTTERS/PAUSESThere is probably nothing more exasperating than to have a bogey lined up in your sites, about to pull the trigger, then the screen freezes/pauses!
Pauses like that are normally attributable to resource starvation in the computer. That can be CPU, memory, video card, and/or sound card related. It can also be due to Windows trying to shut down power or hibernate any given device as Windows does not seem to know when a game is running.
See Power Management in this post, for more information.The freeze or stutter itself is caused by the computer having to make room for a new resource, or load something from the hard drive. A short pause/stutter is normally just a texture or sound being loaded. Once loaded, the texture/sound data will stay resident in memory, unless the computer runs out of resources.
In most systems, it is probably system memory related. Cutting down the "Maximum Texture Size" in the game's "Video Settings" is the quickest way to determine if it is resource related.
On NVidia video cards, the 9x.xx drivers can also cause massive stuttering as well, particularly if you have a multi-core CPU. These were the first drivers where NVidia tried forcing multi-threading and they were a mess.
On-board sound chips use more CPU cycles than a good PCI card would. So if your CPU is at the edge of having too much to do, these chips will push it right on over the edge. Adjusting the hardware sound acceleration down a notch from 'Full' will help reduce the CPU load. Note, in Vista/Windows 7 it is no longer possible to adjust the hardware acceleration as Microsoft as gotten rid of DirectSound and plays all sounds through the normal Windows sound API. Best guideline is to never use custom sounds with Vista/Windows 7 in conjunction with onboard sound devices.
If you have loaded custom sounds, you could experience all manner of resource issues, regardless of the operating system, as most of the custom sound packs use very large sound files at high sample rates. Onboard sound chips just cannot process that many of those types of sound files without running into resource issues. And those files take up enormous amounts of memory in your computer as well, which could exacerbate any resource related issue.
Lastly, the number of and type of background processes is a contributing factor to poor performance. Open the Windows Task Manager (Ctrl-Alt-Del), select the "Processes" tab. In the lower left corner is the total number. It should be around 19 to 21 for a reasonably clean Windows XP/2000 system. A fairly clean Vista/Windows 7 system will have around 35 processes.
Right next to the total count is the CPU usage percentage. For Windows XP/2000/Vista/Windows 7, it should be bouncing like a heartbeat between 0 and 1 (maybe 2 on occasion) percent. If there is any deviation to this, then something is amiss. You can also start the game, minimize it (ALT-TAB), then check the game's CPU usage. It should be at 99 to 100%. In a dual-core computer system, due to the way Microsoft displays CPU usage, the game should be at 50% CPU utilization without any deviation.
If the processes look good and the CPU usage is fine, then you are probably pushing the video card too hard. Simply uncheck the "Detailed Terrain" option in the Options->Graphic Details->Advanced panel. Reduce the "Maximum Texture Size" in the game, disable any anti-aliasing you have forced on, as well as any anisotropic filtering you have forced. Then go from there.
The "Detailed Terrain" option requires a video card to be able to process a high number of calculations per frame. If the video card's GPU (graphic processing unit) is too slow, it will cause massive stutters in the game. A general guideline is, if the video chip is an onboard video chip, such as an Intel, or NVidia 61xx series, then do not bother trying to run the game with this option enabled. Onboard video chips are not designed to be powerful units. They are designed to be cheap.