Question about MMU...

finalmars · 08-02-2010, 02:35 PM #1

Please someone can explain to me what the effect of MMU speed hack is ?

and should i enable or disable it in most of the games ? is there any benefits by this ?

thanks for your explaination cause i could not understand it from the change log...

**NaturalViolence** · (This post was last modified: 08-02-2010, 03:39 PM by NaturalViolence.)

The MMU (memory management unit) is a part of the cpu that allocates space in virtual memory to programs, it was originally used to keep programs from trying to use the same parts of the memory. In fact the modern gui os was only possible after this unit was added to the x86 architecture since a gui os requires many programs running at once. It can be controlled by a series of instructions that were first introduced in the 286 (386 probably introduced some more).

By turning on the hack I would think that you are essentially allowing dolphin to issue these instructions which makes many games that previously did not boot playable. However I would think that that compiler would issue these automatically on any program from what I know about it, you'll have to ask skid for a more in depth explanation, after all he wrote it.

Simple put if a game is already working you should not turn this on since it will only cause problems, however if the game previously did not work turning this on may allow it to run. Many games such as star wars rogue squadron need this on in order to run but a lot of games have serious problems with this on so only turn it on when you need to.

**skid** · 08-02-2010, 05:12 PM #3

(08-02-2010, 03:29 PM)NaturalViolence Wrote: Simple put if a game is already working you should not turn this on since it will only cause problems, however if the game previously did not work turning this on may allow it to run. Many games such as star wars rogue squadron need this on in order to run but a lot of games have serious problems with this on so only turn it on when you need to.

I can't explain it any better than that.

ShadowFX · 08-02-2010, 06:12 PM #4

Then I have another question regarding other games potentially having problems with it. Maybe I'm thinking too simple but if other games don't use it, why would it affect those? Unless the hack is doing things it isn't supposed to do in the system.

**skid** · 08-02-2010, 10:48 PM #5

Aside from the performance issue, enabling the MMU should not have an adverse effect. If it does, there is something lacking in the MMU emulation.

ShadowFX · (This post was last modified: 08-03-2010, 04:56 AM by ShadowFX.)

Okay, that clears it up. Thanks.