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Re: PCem 12 and slowmotion issue

Posted: Sat 25 Feb, 2017 11:28 pm
by omarsis81
I didn't take the screenshot, but during gamplay if I press ESC and the menu appears the CPU emulated percentage drops considerably! I had to go down up to a Pentium 150 to really stay always at 100%. Real madness!

Re: PCem 12 and slowmotion issue

Posted: Sun 26 Feb, 2017 1:36 pm
by leilei
It doesn't slow down in the menu on a real machine with V2.

If I had a wild guess in the dark i'd blame overly frequent framebuffer writing for all 2D stuff.

BTW unrelated but you can get 1024x768 going in Thief if you turn Z-Buffer off first. One of the few games to allow this on a single V2

Re: PCem 12 and slowmotion issue

Posted: Sun 26 Feb, 2017 1:40 pm
by SarahWalker
That's the most likely reason. Other possibilities are that it's idling while waiting for vsync, and it's mostly running the PCem-unfriendly Windows 9x idling code.

Re: PCem 12 and slowmotion issue

Posted: Sun 26 Feb, 2017 4:15 pm
by szadycbr
its all fine in software mode, on both voodoo and virge dx, its also fine in menu on virge dx in hardware mode, the slowdown happend only on voodoo HW. I know the virge is an awfull card for d3d but game in HW mode on it looks like that. just for an info, cos i think the game may simply be incompatbile with virge dx , same as resident evil 1 or 2 , i dont remember.

Re: PCem 12 and slowmotion issue

Posted: Sun 26 Feb, 2017 11:32 pm
by leilei
Virge has no blending caps so not surprised at all. It'll also look like this on the similarly limited Matrox G100A and PowerVR PCX2

Re: PCem 12 and slowmotion issue

Posted: Mon 27 Feb, 2017 10:02 am
by vorob
So, any reason for low speed in simple menu?

Re: PCem 12 and slowmotion issue

Posted: Mon 27 Feb, 2017 1:39 pm
by omarsis81
vorob wrote:So, any reason for low speed in simple menu?
See leilei and Sarah's latest post

Re: PCem 12 and slowmotion issue

Posted: Mon 27 Feb, 2017 6:34 pm
by vorob
Sorry, i missed that, though it still sounds quite complex to me. Is that a problem of PCem? Or its smth complex, bad programming in thief + limits of pcem? Any chance it will be fixed in future? I read that Byzantine also have problems.

Re: PCem 12 and slowmotion issue

Posted: Mon 27 Feb, 2017 8:45 pm
by SarahWalker
It's just complex. The PC is just a complex system to emulate, and some software just hits weak points in the emulator design. Will it be fixed? I'd like to have it fixed, but I can't give any guarantees as to when it will happen.

Re: PCem 12 and slowmotion issue

Posted: Tue 28 Feb, 2017 3:56 am
by omarsis81
The same effects happens when I shut down Windows 98SE
When idling in Windows's desktop the CPU% is always at 100%, but when I shut down and the "It's now safe to turn off your computer" appears the % drops considerably and bounces between 47 and 48%

Re: PCem 12 and slowmotion issue

Posted: Thu 09 Mar, 2017 6:32 am
by leilei
omarsis81 wrote:
leilei wrote: Also my Pentium II 300MHz (Deschutes core) can only attain speeds equal to PCem's PMMX166 right now so maybe either PCem's emulating too fast OR my P2 is unusually slow and I forgot the performance it should have had
How do you measure your Pentium II performance? Game's FPS or any benchmark? SiSoft Sandra is a very good one!
Also, what chipset do you have?
Remember that those cheap PC Chips motherboard had appalling performance
440LX

here's some Sandra '99 results, which seems normal for it.
sandracpu1.png
sandracpu1.png (22.67 KiB) Viewed 4425 times
sandra2.png
sandra2.png (23.83 KiB) Viewed 4425 times
Q3A in q3dm1 runs at 24fps outside on the V2, which lines up with PCem PMMX166's v2 24fps outside result.

Re: PCem 12 and slowmotion issue

Posted: Thu 09 Mar, 2017 11:13 am
by ecksemmess
Interesting. Do we have any idea why the discrepancy there is so big? The fact that PCem is getting performance comparable to your 300 MHz system at a little over half its clock speed seems pretty out of whack. That's too much of a difference to be due to the obvious culprits like the "infinite" cache, lack of emulation of CPU architecture limitations that cause slowdown, etc., right?

Re: PCem 12 and slowmotion issue

Posted: Thu 09 Mar, 2017 12:35 pm
by omarsis81
leilei wrote:
omarsis81 wrote:
leilei wrote:
here's some Sandra '99 results, which seems normal for it.
sandracpu1.pngsandra2.png

Q3A in q3dm1 runs at 24fps outside on the V2, which lines up with PCem PMMX166's v2 24fps outside result.
Can you post the RAM benchmark too? I found a huge discrepancy there, maybe that's the cause...

I think I have a 300 mhz Deschutes to test too but with a 440BX mobo, but your results seem quite normal. I will post my results in a a couple of days, but, like I said, the performance gap we see with PCem for me is because RAM speed (see Sandra RAM benchmark and also MASSIVE FPU emulation as I posted recently here: viewtopic.php?f=3&t=628 . Sarah said she will adjust the algoritm in the future)

Re: PCem 12 and slowmotion issue

Posted: Sat 11 Mar, 2017 3:07 am
by omarsis81
Here are my results:
Klamath 300 w/ 440 BX
Sandra 99
san99-cpu-kla300.png
san99-cpu-kla300.png (22.76 KiB) Viewed 4354 times
san99-mm-kla300.png
san99-mm-kla300.png (23.78 KiB) Viewed 4354 times
san99-mem-kla300.png
san99-mem-kla300.png (23.64 KiB) Viewed 4354 times
Run a Memory Benchmark on a PCem's Pentium MMX and you'll be surprised!

Re: PCem 12 and slowmotion issue

Posted: Tue 15 Jan, 2019 1:24 pm
by vorob
SarahWalker wrote:
Sun 26 Feb, 2017 1:40 pm
That's the most likely reason. Other possibilities are that it's idling while waiting for vsync, and it's mostly running the PCem-unfriendly Windows 9x idling code.
Hi, just wanna to try my luck, was there any movement on this issue? Thx!

Re: PCem 12 and slowmotion issue

Posted: Tue 15 Jan, 2019 3:46 pm
by omarsis81
vorob wrote:
Tue 15 Jan, 2019 1:24 pm
SarahWalker wrote:
Sun 26 Feb, 2017 1:40 pm
That's the most likely reason. Other possibilities are that it's idling while waiting for vsync, and it's mostly running the PCem-unfriendly Windows 9x idling code.
Hi, just wanna to try my luck, was there any movement on this issue? Thx!
Latest news was that the next revision of PCem (v15) is due *possibily* this Summer (UK) with the new recompiler, he could wait and see if that fixes this issue, if not, I´m sure is in Sarah's to do list for the future

Re: PCem 12 and slowmotion issue

Posted: Thu 01 Aug, 2019 1:56 pm
by vorob
Nope, absolutely same picture. Menu lags like hell :(

Re: PCem 12 and slowmotion issue

Posted: Thu 01 Aug, 2019 8:59 pm
by leilei
The new dynamic recompiler has nothing to do with the voodoo emulation choking on DirectDraw buffer writes. There's other games that slow down for the same reason (Omikron's menu, Mechwarrior 3's menu, Urban Chaos's ripples, Metal Gear Solid's water/ninja effects)

Re: PCem 12 and slowmotion issue

Posted: Fri 02 Aug, 2019 1:32 pm
by vorob
Whan can be done on this matter?