vsync = positive sync polarity PD5.41?

[derah]

In Display Properties\Advanced\Monitor Settings , Positive Sync Polarity is checked and the Vertical Refresh rate is shown as 85Hz. G400max refresh is set to Optimal and on the Monitor Settings screen is shown as 85Hz.
Is enabling Positive Sync Polarity in the vertical refresh column the same as Vsync
enabled? Would this setting effect games in OGL and d3d the same? Yes, I have read the many excellent posts on this subject on the MURC board but get the impression
that vsync can only be set thru registry hack or G400 tweak utility.
Clarification is welcome.


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ASUS P3BF 440BX MB,Intel PIII 500 Mhz, 128MB RAM,Fujitsu 13 GB HD, Creative 48X CDROM, Matrox G400 Max Bios 1.5.22, IRQ10, (ver 5.41), SB Live MP3+, IRQ 11(ver 4.06.711) sound card with Liveware3.0, DX7.0, Linksys 16bit ethernet card for T1

[Spire]

The short answer:

No.

The long answer:

"Vsync" (vertical sync) is always enabled on every video card and every monitor. Vertical sync refers to the very short period in between refreshes then your display's electron gun turns off so that it can travel from the end of the bottom scan line back to the beginning of the first scan line.

I believe the option you're interested in is "wait-for-vertical-sync-before-redraw". This is a video driver/application option that minimizes "tearing" problems by changing data in the video buffer only during vertical sync intervals (i.e. in between frames instead of right smack in the middle of a frame).

With the PowerDesk drivers, the "wait-for-vertical-sync-before-redraw" option has to be set in the Registry directly, although there are third-party or unsupported utilities that will do this for you.

"Wait-for-vertical-sync-before-redraw" has absolutely nothing to do with sync polarity.

[Kruzin]

Matrox refers to vsync as "flip on vblank", and it can be controlled with Matrox's tweak util, or with registry hacks available on MURC's d/l pages...

[derah]

Thanks for your replies. I was trying (again) to get rid of the shearing in HalfLife.Its the same in D3D or OGL HL support says its probably due to vsync problems. I have a 19" Viewsonic monitor which supposedly is capable of handling 85Hz vertical refresh up to 1280X960X32.I get the 5 bands of horizontal shearing even at 800X600X16. In the Matrox Display Properties/Advanced/Monitor Settings screen it shows Vertical Refresh set at 85Hz and Standard Refresh at 85Hz. The Adapter screen shows refresh set at "optimal" for the G400max. I tried dropping the Vertical refresh down through 85,80,75,70,65, and 60 and at all lower refresh rates see a whole wave from top to bottom of the image being "redrawn" . This happens superimposed over the horizontal bars of shearing I am trying to remove.They appear to be seperate events.Back to Monitor 85Hz and G400max Optimal. I did use the search on the MURC forums and read the many discussions before posting the first time. I think they conlude that (1)Vsync is always disabled with PD5.41.(2)can enable vsync with the matrox tweak or registry hack but only for d3d (3)OGL games require vsync on/off within their own software.
But heh, at this point I'll try anything.


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ASUS P3BF 440BX MB,Intel PIII 500 Mhz, 128MB RAM,Fujitsu 13 GB HD, Creative 48X CDROM, Matrox G400 Max Bios 1.5.22, IRQ10, (ver 5.41), SB Live MP3+, IRQ 11(ver 4.06.711) sound card with Liveware3.0, DX7.0, Linksys 16bit ethernet card for T1




[This message has been edited by derah (edited 08 February 2000).]