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Re: AGP




On Sun, 27 Sep 1998, Shlomo Solomon wrote:

> offering AGP slots, I'd like to know if there's any real support for
> AGP in Linux. I'm considering the ATI All in Wonder (mainly because
> of the built-in TV tuner - supported by Linux ????) or one of the
> Matrox boards. I tend to think that advice like - set it up like the
> PCI version and it'll probably work - is not the way to go. I've been

well, we did that for DiamondMM's Viper V330 (AKA Windshield Viper) and it
works fine after you switch around PCI cards to avoid an IRQ conflict.

> told that the use of AGP is supposed to improve throughput, so I find
> it hard to believe that using the PCI settings would utilize the
> hardware as it's supposed to.

well, AFAIK, AGP was designed very closely to PCI specs for a reason,
that's why if you take two cards of the same modell, only PCI and AGP, the
exact same chipset is used on both, and that allowed all the hardware
vendors to support it as soon as they did after the introduction.
basically you pass on the information to the bus controllers' buffewrs and
forget about it (again, AFAIK!) just that with AGP it will pass on
faster... (ofcourse I may be simplifying it)

the main difference that REALLY makes a difference with AGP is that an AGP
card is allowed to get data from the main memory, effectively extending
its memory to look as large as needed. those features ARE driver
controlled, but are really usefull with 3D and gaming, those cards will
have the same speed if it's just for 2D, even if you use PCI versions
anyway...


on a final note, AGP is an Intel standard. Intel promissed to help the
Linux community quite a few times in the last few months, specifically
with I2O and Merced specs, and will announce on Tuesday about investing in
RedHat (!), I believe AGP specs and drivers are on the way too...

-- 
Ira Abramov    <ira(a)scso.com>     whois: IA58   (a linux enthusiast)

She sells cshs by the cshore.       - Rob Malda