Crossfire question

[Martincattoms]

Hello.

I am upgrading soon and I am down to a few candidates for a video card.

I am wondering about the finer points of Crossfire. When I upgrade I will be using a single card, but since the PSU and M/board can easily handle X-fire, I need to know more to make a better choice of video card.

I am looking at getting a Sapphire X800 GTO 512. It is only $172 (cdn) and I am hoping the extra memory will offset it is only an 800. There is also an X850XT 256 for $215. I am on a tight budget so the X800 is winning out right now.

But.....

I know to run x-fire I will need two cards that are the same. However, do they have match exactly or just the necessary parts? The M/board can support two cards at 16X each.

If I get the X800 do I need to get another X800 GTO Crossfire master in the future?

If not, does it just have to be an X800 with 512 Ram?

I don't want to screw up my future crossfire plans by choosing the wrong video card now. I also won't O/C much. I can't afford frying anything and having to buy new stuff all over again.

Any help would be great.

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Oh, here is my planned hardware upgrade. I am on a tight budget so I am trying to get the best bang for my buck. Right now I am running an AMD 2400 on an ASUS M/board at 266 FSB and a 9800 Pro at 4X. I should see some improvement heh.

Motherboard PC-A9RD580Adv

Video Card (still don't know yet)

Power Supply Antec NEO 550HE

CPU (AMD 3000) I can easily upgrade this when the prices drop.

OCZ Platinum RAM

 

[tmac]

I thought to run in SLI mode, they have to be the same. But crossfire they can be different.

 

[Martincattoms]

The Primary card has to be a 'Crossfire' card and the second can be a 'Crossfire ready' card.

I know they can be different clock speeds and if one has 12 pipes and one has 16, they both run at 12.

I just need to know whether the RAM has to be the same or not. and how much of a difference an extra 256 video RAM would be...

 

[cleeve]

256mb vs 512mb doesn't make all that much difference 90% of the time.

 

[firepyro555]

Each card has to be the same GPU, but one of them has to be a crossfire master card and the other a crossfire ready card, unless you go with the X1300 the X1600, and i think maybe the X1800GTO. Then the 2 have to be crossfire ready.