did you install the monitor driver?
https://www.samsung.com/ca/support/model/LS22LRZKUV/ZC/

What graphics card? Are you sure it can actually do 75 Hz @ 1920x1080 at all?

Yes, but it doesn't support Refresh Rates more than 60 Hz.
The thing is -- I'm trying to add "custom" refresh rate, basically to "overclock" the monitor. I could do it successfully in Windows 10.

Graphic card is GeForce Ti4200-8X. You mean this resolution might not be supported at this refresh rate, but lower resolutions can do 70 Hz?

lafoxxx wrote on 2020-05-05, 15:29:

You mean this resolution might not be supported at this refresh rate, but lower resolutions can do 70 Hz?

Yes, that's possible. The RAMDAC must be able to handle that, you can't just freely increase that.

The GeForce Ti4200-8X however should be able to do 85 Hz at that resolution. What monitor did Win98 detect? Did you try the monitor driver that wirerogue linked to?

You can try universal vesa driver:

https://bearwindows.zcm.com.au/vbe9x.htm

Single link DVI has up to 165MHz pixel clock by spec, 1920x1080 at 60Hz uses up 148.5MHz of that, 70Hz is already past the limit with 173.25MHz, so timing must be altered by reducing blanking and porches size (there's 2200 pixels output per line of which only 1920 carry visible information), the monitor may not support such altered timings though and video card driver is unlikely to have such timings in it either. You can use software such as PowerStrip to create custom resolution and possibly get working image output.

Another option is use of VGA, which usually has 400MHz pixel clock limit (to reach 2048x1536 at 85Hz).

Are you running through DVI or VGA ? I would expect 70 Hz to work with a custom resolution through VGA as long as the RAMDAC can handle it . I really do not know if older cards (or their drivers) can override refresh rates over DVI, but as Tiido wrote, Powerstrip is the best tool to try for that .

That being said, why are you trying to run at 70Hz ? Even if you succeed in running Windows at 70Hz, it will not give you 70Hz in a full screen DOS Windows or in pure DOS, if that is what you are looking for .

Additionally, your monitor may accept 70Hz, but that does not guarantee it displays it . Some (maybe many) monitors actually skip frames when fed anything other than 60Hz . This is not always easy to see as such monitors are designed to skip frames evenly over time to minimize the visual impact .

derSammler wrote on 2020-05-05, 15:49:

What monitor did Win98 detect? Did you try the monitor driver that wirerogue linked to?

It initially detected sdome generic (unknown) PnP monitor, and I pointed to official driver from Samsung (same as provided by wirerogue).

MAZter wrote on 2020-05-05, 16:18:

You can try universal vesa driver:

https://bearwindows.zcm.com.au/vbe9x.htm

Thanks MAZter, I'll give it a try!

Tiido wrote on 2020-05-05, 16:32:

Single link DVI has up to 165MHz pixel clock by spec, 1920x1080 at 60Hz uses up 148.5MHz of that, 70Hz is already past the limit with 173.25MHz, so timing must be altered by reducing blanking and porches size (there's 2200 pixels output per line of which only 1920 carry visible information), the monitor may not support such altered timings though and video card driver is unlikely to have such timings in it either. You can use software such as PowerStrip to create custom resolution and possibly get working image output.

Another option is use of VGA, which usually has 400MHz pixel clock limit (to reach 2048x1536 at 85Hz).

I use Dual Link DVI cable. For 70 Hz, no timing alterations are required.
I tweaked them when I wanted to achieve absolute maximum of 75 Hz -- i could only achieve it in CVT-RB mode. In VGA, the maximum refresh rate was 71 Hz -- also with CVT-RB and (possibly) timing tweaks.
I'll try using PowerStrip as well, thanks.

darry wrote on 2020-05-05, 16:56:

why are you trying to run at 70Hz ?

Among other reasons (can't stand 60 hz -- used 85 when had CRT), I want to see if DOOM (either vanilla or source port) will run more smoothly (its framerate is capped at 35 FPS).

lafoxxx wrote on 2020-05-05, 16:59:

Among other reasons (can't stand 60 hz -- used 85 when had CRT)

Quite an odd argument, as the refresh rate of a CRT can not be compared to a TFT. To the human eye, a TFT display is always stable, no matter what refresh rate it shows. Also keep in mind that TFT panels have a fixed internal refresh rate anyway and it's only about what refresh rates they accept as an input. At least that's how consumer-grade TFTs work and your SyncMaster is certainly consumer-grade.

derSammler wrote on 2020-05-05, 17:06:

lafoxxx wrote on 2020-05-05, 16:59:

Among other reasons (can't stand 60 hz -- used 85 when had CRT)

Quite an odd argument, as the refresh rate of a CRT can not be compared to a TFT. To the human eye, a TFT display is always stable, no matter what refresh rate it shows. Also keep in mind that TFT panels have a fixed internal refresh rate anyway and it's only about what refresh rates they accept as an input. At least that's how consumer-grade TFTs work and your SyncMaster is certainly consumer-grade.

It doesn't flicker, yes -- but I see the difference when I play games or even simply move mouse pointer.
85 (and even 70) Hz CRT will always bring smoother picture than when using 60 Hz LCD -- unless you're using newer models with up to 144 Hz support.
When using 60 Hz LCD, it's still like slideshow for me -- even though it's "more stable" slideshow "without flickering".

lafoxxx wrote on 2020-05-05, 16:59:

I use Dual Link DVI cable. For 70 Hz, no timing alterations are required.
I tweaked them when I wanted to achieve absolute maximum of 75 Hz -- i could only achieve it in CVT-RB mode. In VGA, the maximum refresh rate was 71 Hz -- also with CVT-RB and (possibly) timing tweaks.
I'll try using PowerStrip as well, thanks.

Ti4200 uses SIL164 DVI transmitter chip for a single link DVI output, with 165MHz limit as imposed by the transmitter chip, a dual link cable will not help here unfortunately.
EDIT: Some cards use TFP410 chip as the transmitter, but same limit applies

lafoxxx wrote on 2020-05-05, 16:59:

It initially detected sdome generic (unknown) PnP monitor, and I pointed to official driver from Samsung (same as provided by wi […]
Show full quote

derSammler wrote on 2020-05-05, 15:49:

What monitor did Win98 detect? Did you try the monitor driver that wirerogue linked to?

It initially detected sdome generic (unknown) PnP monitor, and I pointed to official driver from Samsung (same as provided by wirerogue).

MAZter wrote on 2020-05-05, 16:18:

You can try universal vesa driver:

https://bearwindows.zcm.com.au/vbe9x.htm

Thanks MAZter, I'll give it a try!

Tiido wrote on 2020-05-05, 16:32:

Single link DVI has up to 165MHz pixel clock by spec, 1920x1080 at 60Hz uses up 148.5MHz of that, 70Hz is already past the limit with 173.25MHz, so timing must be altered by reducing blanking and porches size (there's 2200 pixels output per line of which only 1920 carry visible information), the monitor may not support such altered timings though and video card driver is unlikely to have such timings in it either. You can use software such as PowerStrip to create custom resolution and possibly get working image output.

Another option is use of VGA, which usually has 400MHz pixel clock limit (to reach 2048x1536 at 85Hz).

I use Dual Link DVI cable. For 70 Hz, no timing alterations are required.
I tweaked them when I wanted to achieve absolute maximum of 75 Hz -- i could only achieve it in CVT-RB mode. In VGA, the maximum refresh rate was 71 Hz -- also with CVT-RB and (possibly) timing tweaks.
I'll try using PowerStrip as well, thanks.

darry wrote on 2020-05-05, 16:56:

why are you trying to run at 70Hz ?

Among other reasons (can't stand 60 hz -- used 85 when had CRT), I want to see if DOOM (either vanilla or source port) will run more smoothly (its framerate is capped at 35 FPS).

Seeing the difference is a good reason in my book. But as mentioned before, Windows refresh settings do not apply to fullscreen DOS, so you will not be getting 70Hz for vanilla Doom or a DOS source port .

Good luck and let us know how it works out .

Try it with powerstrip, it has monitor setting where you can set almost everything..

Tried using Powerstrip. Here are results so far:

In Quake and even vanilla (DOS) DOOM refresh rate was 72 and 70 Hz, accordingly (checked in monitor OSD).

This was achieved by checking some box in the program, which tells computer to use this framerate on all resolutions.

The framerate was smooth even in UnrealT, at 75 Hz.
By "Smooth" i mean "every frame had same duration in milliseconds" (as it should be when monitor, GPU, program and OS natively supports this framerate).

BUT

In Windows, cursor movement was twitchy, and looked like this:

This effect was worsening gradually -- depending on which framerate is used.

Probably Windows Explorer only works with _natively supported_ framerates correctly. I don't remember my pointer moving like this when I had a CRT monitor which supported up to 85 Hz at 1024x768.

I also wanted to check if using other monitor (native 144 Hz support) will show same result with cursor, but it refused to run ar more than 60 Hz even with drivers.

Haven't tried the VESA driver yet.

TL,DR:
Powerstrip works flawlessly in games, but not in Windows Explorer.

lafoxxx wrote on 2020-05-05, 20:24:

Tried using Powerstrip. Here are results so far: […]
Show full quote

Tried using Powerstrip. Here are results so far:

In Quake and even vanilla (DOS) DOOM refresh rate was 72 and 70 Hz, accordingly (checked in monitor OSD).

This was achieved by checking some box in the program, which tells computer to use this framerate on all resolutions.

The framerate was smooth even in UnrealT, at 75 Hz.
By "Smooth" i mean "every frame had same duration in milliseconds" (as it should be when monitor, GPU, program and OS natively supports this framerate).

BUT

In Windows, cursor movement was twitchy, and looked like this:

This effect was worsening gradually -- depending on which framerate is used.

Probably Windows Explorer only works with _natively supported_ framerates correctly. I don't remember my pointer moving like this when I had a CRT monitor which supported up to 85 Hz at 1024x768.

I also wanted to check if using other monitor (native 144 Hz support) will show same result with cursor, but it refused to run ar more than 60 Hz even with drivers.

Haven't tried the VESA driver yet.

TL,DR:
Powerstrip works flawlessly in games, but not in Windows Explorer.

Well, I am impressed. I was not expecting Powerstrip to be able to affect refresh under full screen DOS in mode 13h , but I guess you learn something new every day . That cursor thing on the Windows desktopis strange, though .