PD5.13 reghacks-triple buffering

[efloyd]

Could someone review the details of triple buffering on and off for the G-200?
Thanks!

[Guyver]

Look at the links for downloading the latest registry hacks from either the News section or the Download section of Matrox Users. They include triple buffering, Anisotropic, Vsync ... and possibly more by now...

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Running an ABIT BX6 R2, PIII-450 @ 581Mhz, 128MB (64x2) PC100SDRAM (running @ 129), Matrox Mystique G200 8MB, SBLive! Value, Adaptec AHA-2940UW (Dual Channel)
All kinds of other SCSI and ATAPI goodies....
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Waiting for my G400Max Impatiently, increasing system performance to give it a good home.....

[efloyd]

Maybe the question was unclear. I know where to get the reghacks, I would like an explanation of the pros and cons of enabling triple buffering.
Thanks,

[suffer]

Im sorry, this has nothing to do with your question... but, what is the effect of the Anisotropic reg?
I have actually never seen this until the newest reghacks were released... am I stupid?

thanks.

[efloyd]

Evidently not as stupid as me for not knowing under what circumstnaces triple buffering would aid performance. I, for sure, have no idea about Anistropic whatever....

[Nuno]

Triple buffer will speed things up if you have vsync on (and enough memory to do tripple buffer.

With Vsync on your g200 is dependant on your monitor refresh rate to render a frame. It only displays it if the monitor is refreshing at that precise moment: that´s why you need a buffer. Normaly it does dobble buffering, that is like rendering a frame in one portion of memory while keeping the previous one in another portion. This one is displayed in the screen.

If you store 3 consecutive frames in the memory (tripple buffering) it´s like you have more chances that a rendered frame is ready to display when the monitor starts refreshing the display, so it will skip less frames, actually improving the framerate and smoothness.

If you have Vsync off, tripple buffer is of no use, because all the frames rendered by the video card are displayed in the screen, not dependant on the refresh rate. This may cause image tearing (if a frame is send to the monitor when it is refreshing the picture, you will see half of both frames).

Tripple buffering and Vsync on gives about the same performance of vsync off, without tearing. But tripple buffering is memory consuming (a g200 8 mb will only tb up to 800x600, I guess) and the game must support it.

Anisotropic filtering is a type of filtering more advanced than bilinear/trilinear filtering. It requires more complex calculations. I don´t think the G200 support it, previous drivers (4.11) should have some kind of software trick, because there was a reg hack to enable it and Tirtanium (or whatever ot was called that time) detected it and there were some visual diferences (and a performance hit also).

I don´t think it works anymore, I tried it and no benchmark could detect anisotropic filtering (tirtanium, 3dmark max).

Hope this helps, don´t know if this info is 100% correct, but you should be getting an idea for now.

[efloyd]

Nuno, thanks for the explanation! It all sounds plausible. So, I think I will continue using only two of the reghacks, forcing agp2x and disabling vsync (to go along with G200CLK beta.21). All seems well in my Celeron 300A/504-Abit BX6r2 system.
Thanks again,

[Maggi]

Hi Nuno,

there are at least two kinds of anisotropic filtering ...

one for magnifying and one for 'minifying'.

The G400 supports the min filters in hardware only. Those benchmarks either want to use the magnifying filter or both of them, thus they report 'unsupported'.

If you'd use the quality test in 3D Winbench 99, you'll see the readout that the min-filter IS supported and can be used in those benchmarks.


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Cheerio,
Maggi

I used to have some posts in my record and hopefully some of the guys 'n' girls will still know me and my system ...

[Maggi]

forgot to mention that anisotropic filtering WAS supported by the G200 in software mode up to PD4.26

I haven't checked if they picked it up again for PD5.x though ...

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Cheerio,
Maggi

I used to have some posts in my record and hopefully some of the guys 'n' girls will still know me and my system ...

[Nuno]

Hi there Maggi

Thanks for clearing that up, I really didn´t know that much about anisotropic anyway. Just that was better than trilinear because it calculates the filtering averaging a variable amount of pixels acording to the part it is rendering...
And how about that magnifying and minifying? How does it works?

And as I said I tryied the anisotropic reg hack, but as far as I can see, it is not working.

PS: Oh yes, and waiting for a G400 DH 16 Mb to arrive next week!


[This message has been edited by Nuno (edited 07-16-99).]

[GTI]

Hi Maggi/Nuno:

I got the same "unsupported" for Anisotropic filtering in 3DMark99Maxpro.

But what puzzled me is that I cannot turn on Anisotropic filter in the G400 Techdemo as well (F5 gives point/bilinear/trilinear only).
If Matrox said it is supported how come they don't let you see it in the Techdemo.

Am I missing something here?? Does anyone get the Techdemo to use Anisotropic filter???

BTW, I already enabled it in the registry.
Thanks, GTI.