wrote in message
...
On Mon, 1 Sep 2003 08:00:47 +1000, "John"
wrote:

Absolutely all G450's are 1.5volt compatible. It was some of the G400's
that
weren't "fully" compatible.

'scuse me for lurking on this thread, but how can you tell what voltage
G400 you have?

I have a G400 Flex (it came with a RT2K video board)--it runs fine on an
El Cheapo ECS K7S5A Mobo.
I'd like to upgrade to a P series, but I don't know what my mobo AGP
voltage is (and the ECS docs are sketchy, to say the least).

TIA,
JoeA
--
Self-government requires self-discipline.

In your case, it doesn't matter what your G400 is. It's what your
motherboard delivers, and what the P series card needs that really matter.

And, because your G400 card is the "flex" model, I don't know much about it.
So the info below may or may not apply to your flex card.

You might be able to get some info about your AGP slot from Sisoft Sandra or
WCPUID (WCPUID is free, look under Chipset Info tab for AGP info). But you'd
be better off to try to find some specs for you motherboard on the net
somewhere.

The "full" G400 designed for AGP4x (1.5volt) slots has a 4A in the model
number (on the matrox sticker on the card itself).

All G400 are capable of voltage switching between 3.3 volts and 1.5 volts.

But you don't necessarily need a G400 with 4A in the model number to work in
in an AGP 4x board. The earlier model G400's will work in some AGP4X
motherboards. It depends on the motherboard (more info below).

Matrox realised they had made a mistake with the circuitry on the
original G400's and revised the circuit board even before the model 4A cards
were issued.

There are at least 3 different types of G400 cards:

TYPE 1) the original G400's 2x

TYPE 2) the revised G400's 2x with revised circuit board number (002 I
think)

TYPE 3) the "full" G400 4x cards (with 4A in model number)

I have a Gigabyte 8IRXP and an Asus P4B533-E. Both of these boards are for
AGP4x 1.5v
cards only. The difference between these motherboards is that the 8IRXP does
not attempt to save itself if a 3.3volts video card is inserted. ie. the
motherboard will burn itself out. The Asus P4B533-E actually checks the
video card
type inserted into the motherboard and will NOT boot with a 3.3volt card.

Now the TYPE 1 cards are detected by motherboards as 3.3volt - so the TYPE 1
card works okay in an 8IRXP (because the 8IRXP does not check the video card
type) but
the TYPE 1 cards won't work in a P4B533 (because the motherboard thinks
its 3.3volt card, but of course its not, because it will switch to 1.5volt)

The TYPE 2 cards will work in any motherboard looking for an AGP 4x 1.5v
card

The TYPE 3 cards will work in any motherboard looking for an AGP 4x 1.5v
card

Because of the auto voltage switching you can insert any Matrox G400 into
any motherboard with takes an AGP 4x 1.5v card and you will not burn it out.