Dime vs. DMA?

[anid]

Quick and (hopefully) simple questions on a subject I have seen mentioned several times, but never knew the answer to.

1) How can you tell which method your card is using?

2) Can the method be changed Under the PD 6.x drivers?

I ask because I am using a G200 Mil SD on an Epox MVP3G-M (S7) board. I have heard that quite a few of the S7 boards that won't do AGP 2X Dime will do AGP 2X DMA (which would be "faster" than 1X Dime). Probably doesn't make a dif, but I'd like to play around with it if possible. Thanks.

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"I wrestled with reality for 27 years and I'm happy to say I finally won out over it."

[Maggi]

Howdy Anid,

DiME = Direct Memory Execution
Example: textures that are stored in your AGP memory can be mapped directly onto 3D objects

DMA = Direct Memory Access
Example: textures first need to be transfered from AGP memory into local (onboard) graphics memory and then can be mapped onto 3D objects

You could use Powerstrip or PCI List from www.entechtaiwan.com to get a readout what AGP mode you're currently running and as far as I have observed AGP1x DiME is faster than AGP2x DMA ...

I don't know though whether you can change the transfer mode through powerdesk's registry settings.

Cheers,
Maggi

[rylan]

As far as I know, the Epox G-M board does DiME in 1x and 2x mode

[dZeus]

anid, I assume you do know that you can't change the AGP mode on a card. It's either DMA or DiME. As far as I know, all the Matrox AGP cards that have AGP texturing (G200 - G450) are DiME.

[anid]

dZeus, in some of the older (original) drivers for the G200 you _could_ change it between Dime and DMA mode.
PCIList just tells me its 1X with Sidebanding, etc. doesn't even mention Dime or DMA (with current v2.22). My G-M will not stably do 2X (with the G200, works with NV cards), it's fine in everything except 2D apps. Weird, huh? It doesn't really matter to me, I just like being able to play with this stuff. I don't doubt that 1X Dime is faster in real world apps, but I had seen mentioned that therotical fillrates would be faster with 2X DMA vs. 1X Dime. Like I said, doesn't really matter, just like being able to play. Thanks Maggi.

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"I wrestled with reality for 27 years and I'm happy to say I finally won out over it."

[dZeus]

that's some interesting info! Thanks Anid!