Will a 2x/4x AGP Motherboard support an 8x AGP card?

[kevinmartin]

I have an IWILL kk266plus motherboard with a VIA kt133a chipset and a 2x/4x universal AGP slot. Can I install an 8x ATI RADEON 9600 128MB video card?

From everything I have read, the 8x card should work on my board, but installation hasn't been going too smoothly. I've updated the VIA drivers and updated the BIOS, but the darn thing won't boot with the new ATI card. If I put my old nVidia 4x card back in, it works great.

Thanks.

 

[Cawchy87]

yes, it will work

 

[Peter]

Yes it does, in theory, since all 8x AGP gear must (must!) support 4x mode too.

In practice, some older BIOSes get confused with the 9600 since it has been the first card on the market to actually drop 1x/2x AGP support and be 4x/8x _only_

 

[kevinmartin]

Thanks for the info. After about 8 hours of mucking with the card, some magical combination of uninstalling/reinstalling got it working. Of course, I equally wary about it suddenly not working too.

On the up side, it sure looks good. A significant improvement over my GeForce2 MX-400.

Thanks again.
-km

 

[elkinm]

Yes, if it can run at 4x AGP it will support an 8x card but it will only run at 4x AGP speeds which is a small difference at most usually if any at all.

 

[superpilun]

I just bought a 9600se and have been trying to install it in my agp 2.0 (2X/4X) universal slot. I can't get it to boot at all. It just beeps several times. Any ideas on what I can try?

 

[pukemon]

I have an ATI Radeon 9600 (non pro, built by ATI) 128MB and it will work in an AGP4x (VIA KT266A based DFI board) as well as an 8x (VIA KT600 based Chaintech board and also an nForce2 400 Ultra based Shuttle board) slot.

Here's what I've found. The 9600 doesn't seem to play nice with VIA chipsets, well not the two I have. You need to turn of AGP Fast Writes and whatever other BIOS options that probably don't mean all that much anyway. The next thing is you have to find the right Catalyst drivers that work with your board/system. For me, the Catalyst 4.4 and 4.6 worked fine, the 4.5, 4.7, wouldn't work (black screen), and the 4.8 and 4.9 had some stability issues (spontaneous rebooting)

On the nForce2 board, everything worked and all the Catalyst drivers worked. Go figure.

 

[Creig]

An 8x device must be 0.8v
A 4x device can be either 1.5v or 0.8v
A 2x or 1x device can be either 3.3v or 1.5v.

AGP 1.0 and 2.0 devices use a 1.5v key and signal at 1.5v, while AGP 3.0 devices use the 1.5v key and signal at 0.8v. AGP 3.0 devices must be tolerant of 1.5v signalling though they won't necessarily work. But they will not be destroyed if inserted into an AGP 1.0/2.0 slot.

 

[Schadenfroh]

Yes

 

[Peter]

Originally posted by: Creig
An 8x device must be 0.8v
A 4x device can be either 1.5v or 0.8v
A 2x or 1x device can be either 3.3v or 1.5v.

AGP 1.0 and 2.0 devices use a 1.5v key and signal at 1.5v, while AGP 3.0 devices use the 1.5v key and signal at 0.8v. AGP 3.0 devices must be tolerant of 1.5v signalling though they won't necessarily work. But they will not be destroyed if inserted into an AGP 1.0/2.0 slot.

Sorry, that's all mixed up.

AGP 1.0, 2.0 and 3.0 are standard revisions. What the cards actually implement - within the standard - is a different story. AGP 2.0 introduced 4x mode, AGP 3.0 made implementation of 1x/2x modes optional.

Now, modes.

1x and 2x use 3.3V signalling.
4x and 8x use 1.5V signalling. 8x uses a reduced swing of 0.8V, but it's still 1.5V signalling.

3.3V and 1.5V support is indicated by key notches in the card's connector blade, which must match key tabs in the mainboard's AGP slot. Cards that support either voltage have two notches, mainboards that support either voltage have no tabs.

Card supply voltage is always 3.3V.

Card/Mainboard combinations that aren't electrically compatible won't even fit mechanically. (There have been design screwups on either side - early AGP 2.0 cards that have "universal" keying but 1x/2x-only chips, and early AGP 3.0 boards that have a "universal" slot but do only 4x/8x mode.)

http://www.ati.com/support/faq/agpchart.html