Problems with G400

[Mick7]

thanks rags (and EchoWars)
hey rags ... if you ever want to get into anougher hardware debate... e-mail me (-:

[Rags]

I like debating in the open. It gives everyone else a chance to learn at the same time, you know?

Rags

[Mick7]

me to, Iment E-mail me so we can get the subject down (-:

[Mick7]

by the way.. which number indicates 4x compatabilty ? for future refrence

[Rags]

There will be a "4A" in the product number.

Rags

[Mick7]

cool, thanks

[Humus]

Originally posted by Rags:
It does not say on your box it can do 4X transfers, it says it is AGP 2X/4X. This means that it will run in an AGP 4X board (there are some 4X slots that won't fit a non compatible 2X board in it, and the G400 works fine in it).

As far as your motherboard, I don't care how much you say it's good, PC100 and even PC 133 DON'T have the bandwidth to fully supply AGP 4X. You need over 1GB/s to feed AGP 4X. With PC100 you are theroetically going to get a max of 512 MB/s, PC133 gives theroetically a nudge over 750 MB/s. In practice, these rates are never achieved. 4MB cache or not, your motherboard cannot feed AGP 4X. Period. If you want AGP 4X you will need to wait for DDR chipsets or purchase a Rambus system. Sorry.

Rags

PC-100 has a bandwidth 800MB/s (64bit 100 MHz = (64/8)*100=800)
PC-133 has exactly the same bandwidth as AGP4x (1.066GB/s).
AGP4x = (32/8)*66*4 = 1.066GB/s

[Bursar]

Mick7 - If you're ahrdware guy, do I what I did...

I bought a G400 MAX from the Matrox Online shop shortly after they were released. It was a 2x only model.

I recently had to order a vanilla G400 in for someone who wanted the Dual Head features.

My fingers 'slipped' when placing the order and a new G400 MAX was duly delivered.

5 minutes with a screw driver, and hey presto, new 4x AGP MAX in my home machine!!

[Mick7]

Humus: I did the math in my head and it came out below.... guess i should have brought up calc.

Bursar: I have been trying to get a freind to get one but he seams to like the Gforce... go figure. I might ask a friend if he wants to trade, he has a new G400 on a old mother board.... we shall see

[Nuno]

Humus, if you´re trying to make a point that pc133 is enough for AGP4x remember that there are more things than AGP that HAVE to access the system ram simultaneously. So, no, 1.066 Gb/s is not enough.