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MacDann

macrumors 6502a
Original poster
One question: Can it be done? That is, can I run two ATI 5870s in my Mac Pro 3,1?

I'm in the process of moving from two 23" ACDs to two 30" ACDs. I don't do anything that requires major horsepower, but I figured with two separate cards I might get a bit more performance due to each only driving a single monitor.

I'm wondering if I would encounter issues with PCI slots/lanes and/or power supply?

Thanks!

MacDann
 
One question: Can it be done? That is, can I run two ATI 5870s in my Mac Pro 3,1?

I'm in the process of moving from two 23" ACDs to two 30" ACDs. I don't do anything that requires major horsepower, but I figured with two separate cards I might get a bit more performance due to each only driving a single monitor.

I'm wondering if I would encounter issues with PCI slots/lanes and/or power supply?

Thanks!

MacDann

The problem is how to power them. From memory, each 5870 need 2x6pin, and there should be only 2x mini 6pin available on the 3,1.
 
One 5870 "should" be able to drive up to three displays. It's been awhile and do not recall the overall resolution limitations of the card. You would need an adapter for the second monitor to use the mini displayport (Mini DisplayPort to Dual-Link DVI Adapter) if using 30" ACD on one of the two ports. Recall needing to use the official Apple version when it was originally released, but that may have changed since then.

Driving two 5870's you would need to figure out a power solution of some kind. External may be the easiest for a 3,1 but there are people who have come up with other creative options.
 
I'm in the process of moving from two 23" ACDs to two 30" ACDs. I don't do anything that requires major horsepower, but I figured with two separate cards I might get a bit more performance due to each only driving a single monitor

This doesn't make any sense. If you don't need horsepower, a lowly GT120 will work with two displays just fine. Your existing 5870 is certainly up to the task.

By far the vast majority of computer operation won't get faster from adding a second GPU. If you need more "performance", it is important to know what it is that you are trying to improve. Maybe it will be a second GPU, but far more likely a faster CPU, SSD, more memory, etc.

Even if you do need more GPU horsepower, adding a second 5870 isn't a good way to do it. A better card that fits within the cMP's power envelope would be a much better solution.
 
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