Nintendo DS Emulation Hits the PSP - DeSmuME Test Release

**SpacemanSpiff** · August 10th, 2007, 05:45

The difference is the ME is only being used to handle sound emulation with the SNES emulator, while the DS has two CPUs that are each doing way more work than the SNES's sound chip so ME support would give a much bigger boost. Also the GBA only has one processor doing all the work so using multiple processors to emulate it wouldn't make much sense.

**Exophase** · August 10th, 2007, 05:53

Originally Posted by SpacemanSpiff

Exophase, could DS emulation could be achieved with ARM7 emulation being handled by the Media Engine and the PSP's main CPU doing the ARM9 emulation? Would it still be impossible to reach full speed with this setup?

I don't really have much confidence in it... the main CPU is a huge burden, and synchronizing the two would be a pain (they share fast, cacheless memory). The video alone is at least 2x as demanding, but probably often more (especially with 3D). You could perhaps put the sub-screen on really high frameskip.

I don't really know what DS game code is like either, IE how much it pushes the CPUs. Since it has instruction cache it might be that proportionally more code on the ARM9 is ARM rather than Thumb (unlike GBA), which means more work in emulating. And the memory emulation would probably be more complex because the memory subsystem is more complex. I can get some average load games to use about 5ms per frame on PSP - multiply that by 4 and it's 20ms, way above the 16.7ms per frame you need to be fullspeed and with nothing left over for graphics. Don't even want to mention the heavy load games (urgh, FF6)

gpSP's speed isn't always maxing out the PSP, but a lot of the time it could definitely use a more free CPU time. It's not that it's 100% optimal but I personally only know of so many ways to make it faster, and not an awful lot faster.

**maxipower90** · August 10th, 2007, 06:02

Exophase,if you used ME in ur GPSP, would the speed increase?

**zheg_pagaza** · August 10th, 2007, 06:09

everybody eat you all putos
(todos se la comen toda putos)

**Exophase** · August 10th, 2007, 06:12

Originally Posted by maxipower90

Exophase,if you used ME in ur GPSP, would the speed increase?

Maybe, but it'd take a lot of reworking.

**RunawayPrisoner** · August 10th, 2007, 06:34

Oh and... off-topic: You wouldn't believe this, Exo, but Riviera works on 0.8 beta... with the faulty BIOS, although sound is broken. I almost never check back here so I didn't know about those three games... sorry.

**mike_jmg** · August 10th, 2007, 06:38

Exophase is right, ports of emulators are going nowhere even more it the emu struggles to get fullspeed on PC

**goliath182** · August 10th, 2007, 06:46

lol this would be a first a current generation hand held being able to emulate another current generation hand held. even though it would be sluggish emulation