how do i disable agp sidebanding?

[Fro]

I know, this topic has been gone over, but I never found an answer when I searched. only Gurm's griping about performance loss.

I don't want to be lectured on performance issues and "it's your other hardware" and so forth, I just want to know how to do it.

[ayoub_ibrahim]

don't use it myself but I believe that option is available in powerstrip!

[Ashley]

Once the Matrox driver has loaded, any change to AGP configuration will usually hang the system.

It wasn't always this way, but with recent Matrox drivers whatever changes you want to make have to come before the Matrox driver gets a chance to setup the AGP configuration.

With a VIA chipset, you can disable SBA with a registry switch that takes effect before the Matrox driver loads; with Intel, you're out of luck unless Matrox has an undocumented registry switch you can set...

[Fro]

tried it already, didnt work....

[Fro]

damn, jsut the asnwer i wasnt hoping for =\

well i got an email from matrox tech support saying to ask their developer relations, if they DO tell me a way i'll post it just incase someone in the future trys searching for an answer

[Greebe]

Rom should post it here for the rest of the world to see (he's Matrox Dev Rel)

[Gurm]

Fro,

I'm not just griping. It's your choice, but they don't provide an option to turn it off because it's not something anyone would ever want to do.

In fact, after reading your post here I sat down and thought and thought.

And after about an hour, I came to the conclusion that there was absolutely no circumstance in which I would ever want to disable sidebanding.

Ever.

If you can figure out a way, more power to ya. I just can't honestly determine why you would want to do such a thing.

(Prepare for horrifying car analogy...)

It's like saying:

"How do I disable my muffler?"

Now, the muffler isn't NECESSARY to run the car, but it improves performance and makes the car quieter. So the answer is... well, you could cut it off, but WHY would you want to do that? If you do "disable" it, the car will be loud and nasty, have less horsepower, and use more fuel.

But hey... if you WANT to do it, by all means try and figure out how!

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Now, if you are doing this because you think that it will 'fix' some other problem, then my earlier 'griping' stands, and you should fix whatever else is wrong with your system.

- Gurm



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Listen up, you primitive screwheads! See this? This is my BOOMSTICK! Etc. etc.

[FrankDC]

There are a number of reasons why someone might need to disable SBA, including (but not limited to) power considerations (SBA requires more current) and compatibility issues with some OS's (most notably NT).

In fact, reports say SBA enable/disable will be included in the new Matrox line, so the option must have a use after all.

[This message has been edited by FrankDC (edited 02 February 2001).]

[Gurm]

Ahhhh. Ok, there are a couple good reasons. However, I fail to see why you would want to disable it under NT? What exactly is the problem there? My G200 and G400 (and G100, incidentally) ran fine under NT4...

As for the current issue - that would be a problem with LX boards and badly implemented first-gen Athlons, right?

I reiterate that it's the REST of your hardware. Not a Matrox problem.

- Gurm

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Listen up, you primitive screwheads! See this? This is my BOOMSTICK! Etc. etc.

[Ashley]

I just ran a quick check on a G450 and disabling SBA cost about 10% in 3dmark scores.

I assume you're faced with a stability issue, and you have to deal with the hardware you have, so you might want to try turning AGP texturing off in DXDiag - which will have the same effect.

[Fro]

thank you gurm for posting an opinion and not a lecture like i found in the past :P

and no, turning off agp texturing doesnt quite suite my needs. basically i have an obsession with being able to fiddle with everything in my computer, be it bios settings, or pins on video card bios'

whether or not it helps stability isnt the question, it's just a matter of the option beign there or not. yes it has a slight performance drop, but hey, oh well. if matrox didnt include it due to performance decreases, then why bother giving a busmatering toggle? that gives a 50% performance drop(least on my system it did) and yes, it's for overclocking. but since my pc spends more time number crunching than gaming(if i wanted to get a "super elite gaming card" i would have gone with a geforce) i see no real problems if i lose 10 percent of my game performance considering i pull about 60-80 fps in games i play, and 10 wouldnt be that noticeable anyways. so gaming is not the only reason to oc. an sba toggle would be a troubleshooting feature that personally i think they should have included in the first place, but oh well

but back to the topic. tried agpinfo, tried powerstrip, and nada. powerstrip doesnt do anything, and agp info just crashes it since it does it on the fly and not on a reboot before the drivers get initialized. i got my matrox card for quality, not speed. and i wanna be able to break it dammit!

[2Whyzzi]

Um... I don't proclaim to be an expert or anything, but if you want to disable Sidebanding, why not just drop to AGP1x via the Matrox Tweak Utility/Registry hack? Doesn't sidebanding depend on AGP2x before it can be enabled?

And, realistically speaking, has it not been said that there is little performance difference between running AGP2x vrs AGP1x (other than maybe sidebanding)?

But, as always, good luck in your quest.

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Abit BH6 r1.01
Celeron2-566 o/c to 850MHz+Slotket!!! 1.8v
256 Megs PC-133 Cas3
Matrox G400 SH OEM (not oc'd) rev=03h
Diamond Monster Sound MX400

[martinus]

I've just found this thread... oldie but goldie

I am also interested in the answer. Fro, any news? Is it true that AGP1x implicitely switches off sidebanding?

[Ovi]

I think disabling sideband addressing increases stability, and reduces compatibility problems with certain chipsets. On my recently purchased Asus TNT2 Pro (32 MB), SBA is turned off by default, which can only be turned on by flashing a bios with SBA enabled, available at Asus's site. Now that seems to be a pretty drastic step taken by Asus, and the only explanation for this seems to be is that Asus is trying to reduce compatibility problems! Now I would want to enable SBA, but I don't feel too comfortable with reflashing my card's BIOS!!
Cheers
Ovi

[martinus]

Ovi, agreed, for Nvidia based cards the info is available on the web. For Matrox based cards it is not. That's why I'm asking how to disable AGP sidebanding on the G400 in this forum (Matrox Hardware). I'd reflash the BIOS and change the PINS structure if necessary. but how.