Dolphin, the GameCube and Wii emulator - Forums

So I was lucky enough to be able to build a new PC this Christmas My specs are as follows:-

Asus Z97-A motherboard
16GB RAM
Intel Core i7 4790K 4ghz
Nvidia Gforce GTX 770 (just the one)
Windows 8.1 Pro

All in all a nice PC with a very good CPU I think. One of the things I wanted to do was see how Dolphin ran, as I'd heard that on faster computers you can actually play some games almost perfectly. However, every single game I've tried suffers from stuttering. The stuttering is basically random as far as I can see. I'll be playing the game at full speed and it will just pause completely for a split second then resume. It makes playing platform games really difficult, for instance.

I wondered if the problem was a bad driver. Not so long ago I had a PC that stuttered on video that was caused by a driver taking too long in an interrupt so I checked using the LatencyMon test (which measures DPC and ISR execution time) and it says "Your system appears to be suitable for handling real-time audio and other tasks without dropouts". Not that then.

Here are the games I have tried:-

Kirby's Return to Dream Land (EU)
Geometery Wars Galaxies (EU) (On the title screen you can see the spinning galaxy stutter occasionally)
Sonic Colours (US)
F-Zero (US - this dropped to 40fps on some tracks but I'm told that's to be expected, the stuttering thing happened on all tracks though)

I've tried Dolphin 4.0.2 and 4.0-4875 same problem on both. Tried V-Sync on and off, DirectX11 and OpenGL.

There does not appear to be stuttering in other games and programs that I've so far tried.

So is this problem normal and maybe I'm just expecting too much of the emulator or is something else wrong?

Thanks in advance for any advice!

Some games work, some games don't. Stuttering is normal in some games.

The stuttering, if it's shader-cache problems, will slowly go away the more you play games. We have to compile/cache shaders the first time around, and GPUs are slow enough at this task that it causes Dolphin to lag during the compilation. After they are compiled though, Dolphin already has them compiled and can just load them, which means there isn't a stutter a second time shaders are used and so on.

OK thank you, exactly how long should I play for before I can be confident that this isn't the aforementioned shader cache problem? I did play the same opening level on Sonic a few times and there were stutters in different places each time.

If the shader cache is working right, it should only need one playthrough before pretty much everything is generated.

(01-02-2015, 04:43 AM)JMC47 Wrote: [ -> ]If the shader cache is working right, it should only need one playthrough before pretty much everything is generated.

Hmm, so having played through the level two or three times, it's not that then?

Anyone any other ideas

Make sure under windows power options you're in high performance mode, and in the Nvidia control panel you have a profile set for dolphin and that it is on prefer maximum performance.

I had a bad stuttering problem with my PC when I built it too. Make sure you go to Nvidia's control panel -> Manage 3D Settings -> Global Settings -> Power management and set it to maximum performance. I too have a great system and that setting was required or I'd be stuttering and chopping constantly.

KHg8m3r you beat me by seconds!

I'm the master ninja :p

(01-02-2015, 02:04 AM)JMC47 Wrote: [ -> ]The stuttering, if it's shader-cache problems, will slowly go away the more you play games.  We have to compile/cache shaders the first time around, and GPUs are slow enough at this task that it causes Dolphin to lag during the compilation.  After they are compiled though, Dolphin already has them compiled and can just load them, which means there isn't a stutter a second time shaders are used and so on.

This gets mentioned a lot, which makes me curious to know how this differs from what a real GC/Wii would do. Does the real hardware not need a shader cache, or is it fast enough to generate one in real time? The real hardware obviously doesn't have slowdown problems the first time you play a game, so I'm curious why Dolphin behaves this way.