Which mac pros have dual PCIe slots?

[mistasparkaru]

I am new to Macs and was wondering what versions of Mac Pros have 2*PCIe x16 slots? specifically for multiple graphics cards.

 

[Umbongo]

All Mac Pros have four x16 physical slots and are capable of running multiple graphics cards. Power and bandwidth are other concerns depending on which, and how many, cards you want to run.

http://support.apple.com/kb/ht2838

 

[The-Pro]

I am new to Macs and was wondering what versions of Mac Pros have 2*PCIe x16 slots? specifically for multiple graphics cards.

2008, 2009, 2010, and the one sold currently. Pre 2008 have x16 1.1

On the 2008 you have 2 x16 2.0 and 2 x4 1.1

On all later ones the first and second slot are x16 2.0 and the top two are x4 2.0.

If you are planning on running them in SLI /Crossfire, you cant do that under mac. You need to be in windows.

Also the Mac Pro doesn't have enough power outlets for two powerful cards. You'll need to buy an external power supply. Numerous threads here on how people get these to work to use GT 580's etc.

 

[mistasparkaru]

I only really wanted it for multiple displays, I was hoping to use a few low end graphics cards.

 

[Tesselator]

I only really wanted it for multiple displays, I was hoping to use a few low end graphics cards.

Then all MacPros will do. The MacPro1,1 for example can accept two 8800GTs for 4 monitors. And there may be other configuration which will allow 6 or more displays - but I haven't really looked into doing that. The 8800GT for example can be run on x8 lanes with no apparent differences in speed.

As I understand it for two 8800GTs you only need to use a split cable connected the MB power header. But the 7300GTs don't need cabled power so.... The 7300GT can be a little sluggish here and there tho so I'd shoot for the 8800GT ones if it were me.

 

[The-Pro]

I only really wanted it for multiple displays, I was hoping to use a few low end graphics cards.

allright.
Low end cards wont have enough power to need the full x16 slots.
Have a look around for apple GT 120. Low end, capable of running 2 displays and you can stuff 4 of them into your pro as they run at full speed in the x4 slots aswell.