PCem 12 and slowmotion issue

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omarsis81
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Re: PCem 12 and slowmotion issue

Post by omarsis81 » Sat 25 Feb, 2017 11:28 pm

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!

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leilei
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Re: PCem 12 and slowmotion issue

Post by leilei » Sun 26 Feb, 2017 1:36 pm

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
Last edited by leilei on Sun 26 Feb, 2017 1:40 pm, edited 1 time in total.

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SarahWalker
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Re: PCem 12 and slowmotion issue

Post by SarahWalker » 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.

szadycbr
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Re: PCem 12 and slowmotion issue

Post by szadycbr » Sun 26 Feb, 2017 4:15 pm

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.
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thief dxgx hw.jpg
thief dxgx hw.jpg (96.15 KiB) Viewed 1659 times

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leilei
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Re: PCem 12 and slowmotion issue

Post by leilei » Sun 26 Feb, 2017 11:32 pm

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

vorob
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Re: PCem 12 and slowmotion issue

Post by vorob » Mon 27 Feb, 2017 10:02 am

So, any reason for low speed in simple menu?

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omarsis81
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Re: PCem 12 and slowmotion issue

Post by omarsis81 » Mon 27 Feb, 2017 1:39 pm

vorob wrote:So, any reason for low speed in simple menu?
See leilei and Sarah's latest post

vorob
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Re: PCem 12 and slowmotion issue

Post by vorob » Mon 27 Feb, 2017 6:34 pm

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.

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SarahWalker
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Re: PCem 12 and slowmotion issue

Post by SarahWalker » Mon 27 Feb, 2017 8:45 pm

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.

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omarsis81
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Re: PCem 12 and slowmotion issue

Post by omarsis81 » Tue 28 Feb, 2017 3:56 am

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%

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leilei
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Re: PCem 12 and slowmotion issue

Post by leilei » Thu 09 Mar, 2017 6:32 am

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 1128 times
sandra2.png
sandra2.png (23.83 KiB) Viewed 1128 times
Q3A in q3dm1 runs at 24fps outside on the V2, which lines up with PCem PMMX166's v2 24fps outside result.

ecksemmess
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Re: PCem 12 and slowmotion issue

Post by ecksemmess » Thu 09 Mar, 2017 11:13 am

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?

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omarsis81
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Re: PCem 12 and slowmotion issue

Post by omarsis81 » Thu 09 Mar, 2017 12:35 pm

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)

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omarsis81
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Re: PCem 12 and slowmotion issue

Post by omarsis81 » Sat 11 Mar, 2017 3:07 am

Here are my results:
Klamath 300 w/ 440 BX
Sandra 99
san99-cpu-kla300.png
san99-cpu-kla300.png (22.76 KiB) Viewed 1057 times
san99-mm-kla300.png
san99-mm-kla300.png (23.78 KiB) Viewed 1057 times
san99-mem-kla300.png
san99-mem-kla300.png (23.64 KiB) Viewed 1057 times
Run a Memory Benchmark on a PCem's Pentium MMX and you'll be surprised!

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