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cazzer

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Will a new AGP 8X video card work in a 4X AGP Slot?

Hi

My PC (Pentium 4 2.8GHz) has an Abit mobo with an AGP 4X slot. Can I fit a modern AGP 8X card in here? (e.g. nVidia 5900). Will it work (albeit a little slower) or are the voltages wrong and it will blow up to a million pieces?

Thanks
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Callandor
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Take a look at your AGP slot, and compare it to the AGP card you are interested in.  If the notches match, they are voltage compatible.

AGP key voltage
http://www.ertyu.org/~steven_nikkel/agpcompatibility.html
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cazzer

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Thanks Callandor

Not quite clear though - it implies that an AGP 8X card has to run in an AGP 3.0 slot, capable of supplying 0.8v signalling voltage. An AGP 3.0 slot is identified by having only a 1.5v key - but so does an AGP 1.5 slot!

Nevertheless, now I know that I need to have an AGP 3.0 slot, I can type my mobo part number is Abit's website and get the exact details. Thanks for your help.
Don't get your hopes too high about AGP8X being significantly better than 4X - cards don't use enough bandwidth for this to make a difference: http://www.techreport.com/reviews/2002q4/gf4-8x/index.x?pg=6 
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But the card I have is only a Geforce 4MX, so a new card will give a big boost. Just looked at the mobo diagnostics which tells me the AGP is version 2.0. Now I'm even more confused as the website you gave doesn't mention AGP 2.0!
Bit more graphical explanation to difference (and new assimilation data for Callandor ;) ):
http://www.directron.com/15agpguide.html

A AGP 8x card has to run in a slot that provides 0.8v signaling. Whether it's 4x or 8x, it just has to provide 0.8v. That's it.

8x doesn't have that much performance gain over 4x anyway, and PCI-X doesn't have that much performance gain over AGP - it's all about other bottlenecks.
Hm, it's closing time at work, so busy saying goodbye that I forgot to click "submit" :p What mainboard have you got, cazzer? You can look on the Mfg's website for tech details for your mainboard, it will list what it's compliant with.
I was going to post this link: http://www.ati.com/support/faq/agpchart.html, but since Glenn provided the other one, in it goes into the assimilator ...
Hey, I've just been on that site too. Came up as first hit on Google :p
Anyway, I'm going home, continue building my new AMD64 system. Hope I can finish it any time soon - can do most stuff in Win by now, so I should be able to check here in an hour or so. Got a question too, don't remember what - it's in a mail and outlook is already closed :p
I forget way too much, outlook & PDA are my best tech buddies :p
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My mobo is an AOpen AX4GER. The website just says AGP 4X (no mention of voltages) but the website at ATI suggests that my mobo won't supply 0.8V and therefore I can't run a modern video card. :-(

Upgrade time again...
Here are the system requirements for a 5900.

Pentium® 4, AMD® Athlon® or compatible CPU
32MB system memory
*** AGP 2X or AGP 2X/4X or AGP 8X universal slot ***
Installation software requires CD-ROM drive
DVD playback requires DVD drive

You can upgrade as long as you have the AGP 2.0 or later type slot.

Enjoy.
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Hey Thanks Jimmy! Seems to be a bit of conflicting advice, but I have an AGP 2.0 slot for sure. Try it I guess...
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Callandor
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Thanks guys.
The modern agp 8x video card should work fine it just will be slowed to 4x.
And since there is almost no speed increase when going from 4x to 8x, you shouldn't see any slowdowns!
Just an additional note, I had an ASUS A7N266-E with a 4X AGP slot that would not allow an 8X AGP card to work properly.  ANY, 8X AGP card..  I sent it back to ASUS and they claimed the board was fine, and it must've been the 8X card I tried.  (I tried 4 completely different cards.)
Your mileage may vary of course, but in that instance, an 8X card would not work on a 4X board.
As long as your board's AGP slot isnt notched against installing a card it will work... BTW please dissreguard the comment about 8x not being much faster than 4x that may be true of SIS xaber cards and some low end ATI and NVIDIA MX cards but the technology is in place .... its just a matter of whether or not the card you get can use it. Im running Tribes vengeance on a 4x Radeon 9100 in an 8x slot and im not complaining.

Happy Fragging!!!
The extra bandwith available in 8x is currently not used, this is a technical limitation.
You just said it yourself, you run at 4x agp and you're not complaining... This proves the opposite of what you claim??