# VIA VT400 Chipset problems

## PhanLord

Im tryed couple of kernel that shoudl support VT400 Chipset but I cannt bring those to work on base gentoo kernel 2.4.19-r10 there is no direct support for this chipset and so my system si working wihtout AGP and DMA what makes it very slow at graphics or harddrive access (specially hd access)

has anyone similar Motherboard and solution for these problems ?

I would like to have AGP8x turned on but even AGP 2x would be great.

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## Malakin

2.4.20 has support for kt400.

You'll probably only get your agp running at 4x though, my understanding is that neither agpgart or nvagp currently have support for agp 8x on the kt400. Although as we all know going from 4x->8x gives you about a 1% performance increase at most so it's not worth worrying about.

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## col

kt 400 works for me ... so does agp

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## PhanLord

Well i have 2.4.20 running and I got DMA harddrive access

but still no AGP (at least according to Nvidia proc interface)

agpgart breaks with error

agpgart: Maximum main memory to use for agp memory: 439M

agpgart: Detected Via Apollo Pro KT400 chipset

agpgart: unable to determine aperture size.

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## Malakin

Check your bios to see if you can lower the agp speed to 4x.

Maybe if the board and card want to run at 8x you won't be able to get it working but by lowering it in the bios to 4x it will work, just a guess. I haven't tried a kt400 with an 8x agp video card so I'm not sure what happens.

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## nephi513

The error is because it is trying to us AGP 4X apagture siz, but since it is in 8X mode it gets confused.  AGP 2.0 and AGP 3.0 are total diffrent and so they had to make a work of the AGP Gart stuff.  It is avalable in the 2.5 kernel, but because of the rework it will not work with the 2.4 kernel.

Your only option is to change the AGP Setting in the Bios to 4X instead of 8X, but not all boards support his.  So you  might be stuck untill the 2.6 kernel comes out.

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## Malakin

 *Quote:*   

>  Your only option is to change the AGP Setting in the Bios to 4X instead of 8X, but not all boards support his. So you might be stuck untill the 2.6 kernel comes out.

 

I have a gigabyte GA-7VAXP (kt400), to force it to agp 4x I enter the bios, hit ctrl-f1 which adds more options to the menu, then under advanced chipset features I can set it to agp 4x.

Yours probably has something similar although I think the ctrl-f1 thing is Gigabyte only.

If not you could check for bios updates as the ability to control something like this might be added later.

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## riprjak

 *PhanLord wrote:*   

> Well i have 2.4.20 running and I got DMA harddrive access
> 
> but still no AGP (at least according to Nvidia proc interface)
> 
> agpgart breaks with error
> ...

 

I get this exact same problem on Gentoo-Sources r5 and Pfeifer-Sources 2.4.21-r1_pre4

I have a 4x Radeon8500LE with 64MB aperture size set... not working at all on my Epox 8k9A9I (which is KT400A chipset).

The above message repeats through my DMESG, and the agp_try_unsupported=1 only yields and invalid arguement response from insmod agpgart...  HELP!!!!

err!

riprjak

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## riprjak

 *riprjak wrote:*   

>  *PhanLord wrote:*   Well i have 2.4.20 running and I got DMA harddrive access
> 
> but still no AGP (at least according to Nvidia proc interface)
> 
> agpgart breaks with error
> ...

 

Fixed... but only by going to devlopment sources version 2.6.0_pre1

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