Possible Issue? (GFX FIFO)

[Bighead]

I was playing Xenoblade earlier, running around in Eryth Sea while encoding a video with handbrake, and I started getting an infinite loop of these errors:

Spoiler: (Show Spoiler)

And so on....

Got it to happen 4 times, standard options, without custom textures enabled, using the latest build. When finished encoding I was unable to reproduce. Handbrake is obviously very demanding and it isn't practical to run while playing games on Dolphin, but I wasn't sure if exterior programs putting a lot of stress on the CPU should affect Dolphin's stability.

[StripTheSoul]

Ah, I had a similar issue last week, but I thought it was an Ishiiruka-only issue.
Well, there has been so much (amazing) work on Dolphin's core stuff lately; sure there's gonna be a little bug getting through at some point I guess.

[Aleron Ives]

Which encoder were you using in Handbrake? If you were encoding with x264, it will automatically use all of your cores to achieve the fastest encoding speed possible, which will likely impact Dolphin's performance. I'm surprised the emulator was still running at full speed while you were encoding in the background, honestly.

One thing you could try would be using the --threads switch to change the number of threads x264 wants to use. By default it will use the number of logical cores * 1.5, so if you have a quad-core machine, it will use 4 * 1.5 = 6 threads. If you have a quad-core machine with HT, it will use 8 * 1.5 = 12 threads. If you use 3 threads, that would be the expected number for a dual-core machine, so it might make Dolphin happier at the expense of vastly increased encoding time.

[JMC47]

Encoding what? Putting stress on your computer while using Dolphin's Dualcore Mode is more than enough to cause issues like this?

[Bighead]

@Aleron Ives: Well, 99.9% of the time I probably won't be encoding videos while running Dolphin. It just happened that I found myself converting an AVI to an MP4 of my grandmother's wedding for her while simultaneously testing new textures. Sandy Bridge is aging but still a beast.

@JMC47: Yeah that's what I meant. When my CPU was under heavy load from running handbrake, Dolphin started to become really unstable. I wasn't sure if that was a known/real issue or not, or a caveat of using dual core, so I thought it might be worth mentioning. Outside of that, I've never seen it come up before in all the 100s of hours/builds I've used it. I can run another test later and see if I can reproduce it yet again if needed.

[JMC47]

This is a known issue; you should run in single core if you're doing other stuff on your computer. Dualcore is known to be unstable.

[Durandle]

Out of interest, is that to say that if your computer is fast enough, dual core is stable - or is it that it is just less unstable? The speed improvement of dual-code is hard to give up, it usually makes the difference between playable and totally-not-playable for me. Though the "playable" is just until I get the FIFO error (in some games, such as F-Zero which gets it A LOT).

[JMC47]

F-Zero GX is an exception... I don't know why it's throwing so many unknown fifos as of recent. If you can track down when that started, it could probably be made a lot more stable in dualcore, though it would still reset, it wouldn't ever crash midrace.

[Durandle]

I'll give it a go. It was quite satisfying tracking down the issue of massive performance drops on some NVIDIA cards a while back. May take a while though given you have to get all the way through a lap or so before it happens!

[AnyOldName3]

Maybe record a set of input with Dolphin so you don't have to actually play the same bit over and over yourself. This might need changing whenever a build affecting the game's physics/timings/stick sensitivity occurred, but that wouldn't be the end of the world.