Emulator

Currently working on a TAS of this game with a few other guys, we can simply avoid using that B button move to prevent desyncs for now. It never saves time in the run, is was just convenient.

Can you post a dtm of it desyncing?

Here's a DTM of the TAS so far that'll take you to level two in just a couple of minutes time: https://www.mediafire.com/?dna4w2ri28prmbb For me this desyncs right after the gas station, for another guy on our team it desyncs when your car drives over the grassy area midway through the level.

Settings for emulator are same as rachelb's recommended ones on TASvids forum. Memory card slot set to nothing. Uses real DSP files, not ones that come with emulator.

Found a save file with level 2 unlocked: https://dl.dropboxusercontent.com/u/484730/JamesBondAgentUnderFireLevel2.gci

Your dtm successfully completed level 2 for me.

Getting desync WITHOUT the B move at the lawn section between me (win8 64 bit) and solarplex (win7 64 bit).... I'm not sure what to believe anymore...

Are you sure your settings are the same?

Pretty positive.

Does the dtm you posted before sync for anyone else other than me?

Yes, Veman and I sync up until after gas station. Solarplex desyncs with us at lawn.

I mean does it complete the entire level for anyone else?

No, it is for you??

Yes.

What the shits. See, I was able to finish playback myself when I first finished the level, but then my playbacks after all desync'd... lemme play it back again... God I hope we can solve this... and continue at level 3...

I'm desyncing, shots on first of three guys outside of the building we drive through miss.

Please attempt to confirm that you can get multiple outcomes with the same dtm on the same computer without changing any settings in between. That would help truly confirm the issue.

SYNC'D! The settings when you right click the game on dolphin were different between us somehow.... I'll post back if solarplex is still unable to sync past lawn... God I feel stupid... does Dolphin ignore the config settings and use the game's custom settings by default in the newer versions or...

I just unchecked everything in the game's settings to get the sync.... is there anything that should be left checked for any reason?

What setting? Most should be saved in the dtm, and read from there.

Solarplex is still unable to sync at lawn part, despite unchecking all of the game settings. Veman and I sync all the way through. You can see how this issue got confusing...

I decided to do a less intensive test of using Netplay to make sure nothing's seriously wrong with this game. I went through the first three levels with no desyncs in a simple netplay session.

Aleckermit76: Do all three people tasing it have the same disc md5 and such?

Yeah definitely the same disc.

This issue was a misconception on my part by the way, this move in the game has nothing to do with the issue. There is a savestate accuracy issue in the vehicle levels of this game that causes playbacks to desync. A playback that used little-to-no savestates will sync just fine, whereas if you re-record in the wrong place the playback will be desync'd.

Okay, that's interesting. I'll change the name. If you use Full MMU instead of MMU speedhack; does that fix the issue?

I'll be sure to try that when I have time.

How do you change the Full MMU/MMU speehhack setting?

I right-clicked the game in the Dolphin window and checked "Enable MMU" (by default it's completely unchecked). Started a recording of level 2 and made & loaded savestates in many spots. Played it back and it desync'd at gas station (common desync spot).

The question now becomes: What is actually changing between them? Is it GPU related? (Perf-queries aren't correctly saved in savestates, for instance) or CPU related?

I have no idea and no idea how to find out :(

Issue 7497 has been merged into this issue.

Since this hasn't been posted here yet, desyncs happen for the following gamecube games as well:
F-Zero GX
http://tasvideos.org/forum/viewtopic.php?p=401177#401177

Metroid Prime
http://tasvideos.org/forum/viewtopic.php?p=413807#413807

Spiderman 2
http://tasvideos.org/forum/viewtopic.php?p=397774#397774

Not sure if it's all the same issue, or something else however.

It turns out savestates definitely are not deterministic. I'll be closing this issue momentarily.