Re: Will an AGP 8x card work in a 4x interface slot?
"Man-wai Chang" <toylet.toylet@gmail.com> wrote in message news:462c0f29@127.0.0.1...
> billybob wrote:
> > I'm hoping the 8x cards are backward compatible.
>
> Most do. BUT you'd better check the specification of the product.
Virtually all are backward compatible. A few cards were released
right when 8X hit the market, these cards operated at 0.8V only
and would self-destruct when plugged into a 1.5V motherboard.
Fortunately we haven't seen any of these in the last several years.
Re: Will an AGP 8x card work in a 4x interface slot?
Probably, but not guaranteed. I needed to replace the video card in
an old Tyan mobo computer with 4X socket. Two different Nvidia boards
worked for a few minutes before quitting until restarted, and an ATI
board would not even boot to Windows, though the BIOS messages were
visible. I finally went on eBay and found a board which was only
2X-4X, and it has been working perfectly for nearly a year.
Re: Will an AGP 8x card work in a 4x interface slot?
* Alan Biddle:
> Probably, but not guaranteed. I needed to replace the video card in
> an old Tyan mobo computer with 4X socket. Two different Nvidia boards
> worked for a few minutes before quitting until restarted, and an ATI
> board would not even boot to Windows, though the BIOS messages were
> visible. I finally went on eBay and found a board which was only
> 2X-4X, and it has been working perfectly for nearly a year.
This hardly has anything to do with AGP4x/8x compatibility but more with
how much power the old mobo could deliver (were all the caps ok?), with
a too weak PSU, problems with AGP and gfx drivers or any other of
gazillion reasons.
> Virtually all are backward compatible. A few cards were released
> right when 8X hit the market, these cards operated at 0.8V only
> and would self-destruct when plugged into a 1.5V motherboard.
> Fortunately we haven't seen any of these in the last several years.
Right, simply because it's not true ;-)
In reality, something what you described happened but when AGP_4x_ cards
hit the market. The reason was that AGP4x lowered the signalling voltage
to 1.5v. On AGP the signalling voltage (3.3v with AGP1x/2x, 1.5v with
AGP4x and 1.5v/0.8v with AGP8x) is keyed into the AGP connector
mechanically. There were a handful cards (all of the
pre-Radeon/pre-Geforce Aera!) like several TNT2s, Rage128s and some
charges of the Matrox G400 which came with AGP4x keying but which also
only supported 3.3v signalling voltage. When the first boards with
chipsets working with 1.5v signalling voltage only came out using these
cards resulted in a fried AGP bridge if the mobo didn't had any
protection circuit.
This is basically a problem of the past because it's very unlikely
anyone wants to use a card from that aera in a somewhat newer mobo. And
none of the Radeons and none of the Geforce cards ever has been affected.
However, this has nothing to do with the compatibility of AGP4x and
AGP8x (which *always* is cross-compatible). All AGP8x GPUs do support
1.5v (and the ones with native AGP interface also support 3.3v),
especially since even with AGP8x only a part of the signalling is done
with 0.8v (the other pieces are still 1.5v).
Re: Will an AGP 8x card work in a 4x interface slot?
"Benjamin Gawert" <bgawert@gmx.de> wrote in message news:593k3uF2j4a6tU1@mid.individual.net...
> * nospam@invalid.sbcglobal.net:
>
> > Virtually all are backward compatible. A few cards were released
> > right when 8X hit the market, these cards operated at 0.8V only
> > and would self-destruct when plugged into a 1.5V motherboard.
> > Fortunately we haven't seen any of these in the last several years.
>
> Right, simply because it's not true ;-)
Yes, it is.
> In reality, something what you described happened but when AGP_4x_ cards
> hit the market. The reason was that AGP4x lowered the signalling voltage
> to 1.5v. On AGP the signalling voltage (3.3v with AGP1x/2x, 1.5v with
> AGP4x and 1.5v/0.8v with AGP8x) is keyed into the AGP connector
> mechanically. There were a handful cards (all of the
> pre-Radeon/pre-Geforce Aera!) like several TNT2s, Rage128s and some
> charges of the Matrox G400 which came with AGP4x keying but which also
> only supported 3.3v signalling voltage. When the first boards with
> chipsets working with 1.5v signalling voltage only came out using these
> cards resulted in a fried AGP bridge if the mobo didn't had any
> protection circuit.
>
> This is basically a problem of the past because it's very unlikely
> anyone wants to use a card from that aera in a somewhat newer mobo. And
> none of the Radeons and none of the Geforce cards ever has been affected.
>
> However, this has nothing to do with the compatibility of AGP4x and
> AGP8x (which *always* is cross-compatible). All AGP8x GPUs do support
> 1.5v
A few first-generation 8X cards did not support 1.5V.
>> Right, simply because it's not true ;-)
>
> Yes, it is.
Nope, it's not.
>> However, this has nothing to do with the compatibility of AGP4x and
>> AGP8x (which *always* is cross-compatible). All AGP8x GPUs do support
>> 1.5v
>
> A few first-generation 8X cards did not support 1.5V.
Again, no, that's pure BS. If you had some basic knowledge about AGP
then you'd know that even AGP 8x uses 1.5v signalling for most signals
and 0.8v is only used for certain parts and even there still optional.
So no, it's not possible that an AGP card can work with 0.8v but not
with 1.5v. And I know that none of the ATI Radeon or Nvidia Geforce
chipsets with AGP8x interface are incompatible with 1.5v AGP, not only
because it's not possible but simply because through my employer I have
access to the specification manuals of these GPUs.
But since you are that sure I assume you can come up with some
references, right? Of course you can name AGP8x cards that are
incompatible with 1.5v-only mobos, right?
Will an AGP 8x card work in a 4x interface slot? 
Linear Mode
