Serious performance issues

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dondiego
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Joined: Thu 27 Dec, 2018 12:05 am

Serious performance issues

Post by dondiego » Sun 13 Jan, 2019 9:13 pm

Machine: SIS 496/497?
I've created a win95 SIS 486 PCI machine with a DX4-100, a trident 9400 and a soundblaster 2.0. On my host machine performance is very poor and cpu speed oscillates between 70 and 100% on win95 desktop. My host is a pentium dual core @2.16 and host CPU usage is very low, core 0 is below 50% and core 1 even lower. I tried changing power profile to max performance but no difference. Changing the emulated cpu to an sx 16 still makes no difference.
Another ami 486 clone machine can run a DX2 @100% here. Changing all hardware to match the other machine won't help, no difference.
That machine is somehow screwed, changing the cpu makes it run even slower but is still choppy. And i don't think host cpu usage should be that low. I'm on win7 x64.

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SarahWalker
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Re: Serious performance issues

Post by SarahWalker » Sun 13 Jan, 2019 9:58 pm

Sounds like it could be a video driver issue, have you tried changing the Render Driver option in the Video menu?

szadycbr
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Joined: Mon 21 Nov, 2016 6:23 pm

Re: Serious performance issues

Post by szadycbr » Sun 13 Jan, 2019 10:21 pm

dondiego "CPU usage is very low, core 0 is below 50% and core 1 even lower" are you sure it is wrong? i think 50% or so its all you could get on 2 cores showing in windows , if you change in bios to single core cpu then you should get nearly 100% cpu utilization, so on 2 cores if you are not using voodoo you will always have up to 50% and that is really 100% of that core and 50% of whole cpu , as PCem alone use only one core ,we had a long discussion about it here http://pcem-emulator.co.uk/phpBB3/viewt ... ?f=3&t=613

dondiego
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Joined: Thu 27 Dec, 2018 12:05 am

Re: Serious performance issues

Post by dondiego » Sun 13 Jan, 2019 11:26 pm

Same driver for both machines, auto and i guess it's D3D. Intel GMA 4500M. I tried changing driver but didn't help.
Overall cpu usage is 36%.
I think i've found it, it's the trident driver included with win95, that card was not accelerated. The other machine has a cirrus 5430. But i don't understand why the host cpu usage is so low with both machines.

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leilei
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Re: Serious performance issues

Post by leilei » Mon 14 Jan, 2019 1:35 am

You might also want to look into trying the ATI Mach64 as well, which emulates faster for me but i'm not a fan of its textmode fonts.


IIRC Win95 doesn't ship with a TGUI9440 driver, though DirectX 3 should have one.

dondiego
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Joined: Thu 27 Dec, 2018 12:05 am

Re: Serious performance issues

Post by dondiego » Mon 14 Jan, 2019 11:12 am

It's the 9400CXi, the 9440 was accelerated. I had that card back in the day, i also own several real 9440 pci.
The driver is the trident svga, i've downloaded another specific one for higher color depth and i'll try it but i think it will be the same, i'm using just 256 colors. No problem with a 386 and the 8900c so i guess it's something with the recompiler for the way it oscillates at the desktop.
Edit: same with the new driver as expected. Host cpu usage goes as low as 30%. Upon loading the 95 desktop with several windows open performance goes down to 1% and then back between 70 and 100.

dondiego
Posts: 10
Joined: Thu 27 Dec, 2018 12:05 am

Re: Serious performance issues

Post by dondiego » Mon 14 Jan, 2019 5:57 pm

I've tried the 9440 with a late driver (w95-9685.exe) and it's the same plus severe graphics problems.
Changing to the cirrus cl-gd5430 fixes the issue. So something is wrong with the emulation of those trident cards.
Note that the cirrus 5429 is essentially broken on windows as i posted in the other thread.
Edit: same slowdown with trident 8900d.

dondiego
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Joined: Thu 27 Dec, 2018 12:05 am

Re: Serious performance issues

Post by dondiego » Tue 15 Jan, 2019 6:52 pm

And surprisingly today is running fine with the trident. I only hibernated the host machine, not even restarted it. I changed to the cirrus and back to the trident yesterday and the issue only happened with the trident cards. This must be some obscure problem.
Edit: and today it's slow again.

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