Sorry for necroposting, but this thread seemed like the best place (and it really deserves a bump anyway).
I'm running the game on XP Professional with the child patch and TeamX 1.34 patch applied. I didn't notice any performance problems using the game as packaged by GOG.com, but then my machine (a recent iMac with an nVidia 8800 chip) is fast enough that that's not surprising.
I did, however, have some problems with stuttering audio while playing the game. There would be some mild stuttering on and off, then the computer would get stuck on a sound and repeat it like a jackhammer until the system froze up and needed to be rebooted. This would happen on an irregular basis: sometimes it would go for a while without doing it, other times it would happen after only a few minutes of play (making it possible to get out of the rat caves).
GOG.com's support FAQ suggests playing with the audio acceleration settings as a way to get rid of audio glitches. I tried knocking it down from full to standard acceleration, but did not see any improvement. I was loathe to disable acceleration altogether, as I didn't want to be bothered disabling it everytime I launch this one game. Before I got around to trying this, though, I came up with another solution.
After reading through various threads in this forum it occurred to me that my problem might be related to the performance issues others have experienced, so I tried renaming the ddraw.dll file and presto! The game now works fine, even with audio acceleration at full.
I was able to play the game for a few hours with no problem. Then this morning I suddenly got the black screen problem. Having read this thread, I had been careful to have other no other programs running behind the game. I was puzzled by this, until it occurred to me that just before the problem occurred I had accidentally hit the Windows button, which of course minimized the game to the task bar. Apparently this can trigger the problem as well.
So, to summarize what we know at this point (so future newcomers don't have to read the whole thread):
1. The dated ddraw.dll file included with the GOG.com installation can cause a variety of issues including slow and/or jittery performance, audio stuttering, and system freezes.
2. These issues can perhaps be solved by renaming the ddraw.dll file. (The file can be deleted, but best to rename it to something like "ddraw.dll.disabled", just in case.) This forces the system to use its own, more modern version of the file.
3. Playing the game without the older ddraw.dll can cause an issue where the screen goes black and is redrawn as the pointer is moved around the screen.
4. Timeslip's sfall mod (linked in the first post in this thread) can solve this problem, but its use may result in some corruption of movie playback.
5. When using the sfall mod on a Vista system, the falloutw.exe file needs to be renamed (to something like "fallout.exe").
6. If the mod is to be used in combination with the High Res patch, the High Res patch mus be applied first, as per matthewmw64's Guide (earlier in this thread).
7. It may be possible to avoid the black screen problem without using the sfmall mod by (a) not running other programs concurrently, and (b) not minimizing Fallout to the taskbar. The game basically wants complete and uninterrupted control of the desktop.
This information really needs to be stickied. Or better yet, it should be reorganized for easy reference, together with any other info about technical issues, and stickied as a technical help FAQ.
Thanks to Rainstorm, 404notfound, and matthewmw64 for their efforts in troubleshooting this problem, and for taking the time to post!
EDIT: After playing for a couple days, I've noticed the black screen problem still happens occasionally.
I haven't been running any other applications concurrently with the game, and I've been careful not to hit the Windows button, so I'm not sure what the trigger is (or indeed whether minimizing the game triggered my problem in the first place). Perhaps it has something to do with my security suite (Kaspersky Internet Security), or perhaps it's something else.
So it may be Timeslip's patch is the best way to get rid of the black screen issue. YMMV.
One thing I can say for sure is that renaming the ddraw.dll file certainly cured the audio glitches and hangs I was experiencing. Since these happened much more frequently than the black screen, and usually forced me to reboot the computer, I'd say that's a good trade.
Post edited February 21, 2009 by Midville