Need some insight for graphics setup

[sOwL]

I currently have a flashed HD4890 installed in my MP1,1. I have my original X1900 XT sitting somewhere collecting dust. Drawback is I can't enjoy a second screen in OSX which I started to miss very much. So I plan to try a new setup but I'm not really sure about few things, so anyone that knows better on the subject please enlighten me. Here it goes:

Let's say I put the X1900 XT back in. Then connect it to my second monitor on a dvi port (it's already connected through hdmi on the HD4890). Then even CrossFire the cards together.

1) I understand that Crossfire doesn't work on OSX. That shouldn't prevent the cards to be used separately as normal though, would it?

2) In windows, would Crossfire work just like that (given that I install any needed drivers) or would I need to setup the cables differently (e.g SLI Y-shaped cables)?

3) Back in OSX, would the X1900 XT have a significant difference vs the HD4890 on video performance? Because it will mostly be used for movies. I never got that 'HD' thing anyway, the X1900 supports higher res than 'Full HD' and it's doable through a dvi cable, if you only want video and not sound. Also both cards have the 'Avivo' technology that I'm not really sure what that is but it's supposedly meant for HD video.

So, any thoughts on this?

 

[gpzjock]

How many power cables do they need?

I assume the 4890 uses 2 power cables, how many power cables does the X1900XT need?

 

[goMac]

HD on those cards is just a marketing moniker. Ignore it, it doesn't mean anything. They stuck it on because it sounded cooler.

I'm honestly not sure the X1900 would help even if it could be crossfired. It's such a slow card that it's likely going to drag things down more than it could speed things up.

It might help increase performance to the second monitor in OS X by taking the strain of running both monitors off the first card, but with the entire power situation, it really doesn't seem worth it.

Know it seems like a waste to have a spare X1900XT around doing nothing, but it's such an old (and unstable) card, it just seems best not to bother and leave it in retirement.

 

[sOwL]

Thank you guys for the replies.

@gpzjock - The X1900 needs only one cable. Since I never bought a second cable for the HD4890 and used the second DVD drive for the extra power, I could still get a second cable for the X1900 for a total of 3 power cables.

@goMac - The thing is, only reason I'm thinking of using the X1900 is because I can't use the HD4890 for both displays. So on the mac I only have one display, while both are working fine in windows. So the X1900 could make that happen. Also thank you for clarifying the "HD" part; that's exactly what I thought about it.

 

[gpzjock]

Ah didn't see you modded already. Doh!
I have a flashed HD5870 and it runs a DVI and a HDMI signal simultaneously with no issues.

 

[Boomhowler]

You don't need crossfire to get two GPUs to work simultaneously in OSX. If you can get the extra power chord, just plug it in and both should work driving one monitor each. It worked with a 4890 and a 8800GT at least

 

[sOwL]

Yeh well the crossfire was one of those 'why not' ideas. What I'm really after is a working second display on the mac side, thus why I'm thinking of putting in the old card back. I've ordered the cable from ebay (really really hard to find it in europe) so I'll update when i get it all set up.