From Nexus Wiki
Apparently one of the most overlooked game issues in Oblivion is audio.
Absent a hardware accelerated sound solution, all audio processing in Oblivion must be handled by the CPU (Central Processing Unit). Since the CPU must also handle all the disk accessing, AI processing, and data management, any process that can be offloaded to a dedicated processor will improve overall performance. If there is no dedicated processor handling audio (ie. a dedicated sound card with it's own processor) Oblivion can and will have performance degradation, manifesting as lag, stuttering (especially in intense situations) reduced FPS (Frames Per Second) and even CTD (Crash To Desktop).
Oddly enough, with today's powerful CPU's and GPU's, this problem can be even more aggravating, because the apparent decrease in performance seems more obvious.
If you are experiencing some of these issues:
In the ...\Documents\mygames\oblivion\Oblivion.ini file locate:
And change both 1's to 0
If game performance substantially improves, you have several options to consider.
- Most effective solution is to install a sound card with hardware acceleration (card has it's own processor).
- Try the game with music off and sound effects on (bMusicEnabled=0 and bSoundEnabled=1). If performance is satisfactory, OK, enjoy.
- Try a mod like Quiet Feet Max (will reduce the effects of enemy footsteps)
- Try setting iMaxImpactSoundCount (in the Oblivion.ini file) to a lower value. Unfortunately this affects blocks, hits, etc.
- Try a codec reset (keep in mind that a codec reset may break some other applications):
Audio, in a 3D game like Oblivion, is, in itself a 3D issue. By that I mean that sound effects should be moderated by the position of the player. In other words, if the sound event is far away it should be fainter, if it's off to the left it should sound like it's coming from the left. In order to do this the game must supply the proper information about the nature of the sound, where it's coming from and how far away it is. This, then, becomes a series of calculations that must be rendered on the fly (much like 3D images) and translated into the appropriate signals to the audio amplifiers. This process can use quite a bit of CPU processing power. If your computer utilizes an integrated chip set for audio, it is depending on the CPU to perform these calculations, and, as such is putting a rather heavy load on the CPU.
To add to the confusion, Windows XP and Vista handle sound differently. Vista (and directx10) removed DirectSound and DirectMusic. This means that with a Vista computer and a sound card you must enable hardware acceleration for audio with a third party program (for example: with a Creative X-Fi card you must use Creative ALchemy (a utility that comes with the card)) to translate DirectX calls to OpenAL calls.
NOTE: If you do install a sound card, you will almost certainly have to turn off the integrated sound chipset in your computer's BIOS.
This article is a condensation of information from many sources, all in the public domain, my only contribution is to consolidate things in such a way as to, hopefully, make a useful guide for a user experiencing difficulties.