Also vp uses only 1 core.
Well... I'm not so sure about this.
Yes, I know it was said that since
VP is a single-threaded application, it only uses one core, but I experimented today with Checkpoint, and my experience is different.
That table is one of the worst offenders as far as stuttering goes, even without
UVP. While playing, I was monitoring performance via Task Manager. It seemed that both cores were utilized almost evenly. There was a little imbalance, but for the most part, they were both busy and not 100% utilized (apart from a few momentary spikes). The game still stuttered of course

Then I set processor affinity for VPinball.exe to one core only. The one assigned core was immediately pegged and pretty much stayed between 85 - 100% utilized the whole time while the other core hardly had any activity. It was completely lopsided as expected. Game play got certainly much more choppy.
So this tells me that Windows XP must be doing a pretty decent job at load balancing, even if the app is not multi-processor-aware.
For the record, at least in my case, none of the mentioned tricks I'm aware of help if the game stutters, except for deactivating
UVP. The lamptimer works to a certain extent, but only if I set it at extremely high, and then there is serious lag with the lamp update so that is not an option.
Setting ddraw to 0 or moving the
DMD to the playfield doesn't make a difference.
Some people with way stronger hardware than mine reported stutter with AFM or Twilight Zone - I have absolutely no issue with them, and I do have
UVP on for those. TOTAN works fine as well, but only with no
UVP. However haddonfield's latest TOTAN mod stutters, no matter what.
As I said in another thread, getting rid of stutter borders on applying voodoo or something like that. There is indeed no silver bullet.