I am not a pro at Macs but most of the time manage to figure things out myself. However, I am dealing with an issue right now that I have read the forums, article, manuals, local shops (not too many here in Alaska) etc. and I feel like a lot of the advice is conflicting. I figured it was time to post and see if anyone has a straight forward answer. BTW - I use the MacPro for FinalCut Pro, interweb, and a couple of graphic intense games... I have a Mac Pro 3,1 (early 2008) with a ATI Radeon HD2600 video card in it. I run two monitors, one out of of each DVI outlet. About a month ago one of the monitors stopped working and I thought it was going bad. I swapped the plugs in the video card and they both started working - for awhile. After a few days one of the monitors stopped working again - I switched plugs again and both monitors would work only if plugged into the left plug... This made me think that my problem was with the video card. I did experience some pixelation on a few graphic intensive programs. Last week I took the vodeo card out, cleaned things up inside the computer, and replaced the vdeo card in the slot just above the one where it was - in case it was a bad slot. It worked! I was able to use both monitors normally - for about 5 days. Now I am back to only one monitor and occasional pixelaiton of heavy graphic programs. Does this sound like a graphics card problem? I did notice that in the "About this Mac" that when I switched from the bottom video slot to the one above it the Bus went from a PCIx to PCI. It still works, but I am wondering it it is now in a PCI socket and if that is OK - it worked for awhile... and I still have video - on one monitor. I went to the local computer store and they were ready to sell me the latest off the shelf video card. Luckily I decided to check it out first. It looks like you can not put a PC card in a Mac - right? - that is what they were trying to sell me. If I need to put a graphics card in I would like to upgrade it if I could. I see that there is a ATI Radeon 5770 and a 5870 now. From reading forums I have not been able to tell if either one would work. Some posts say "yes" and others "no." Some posts send me to dead links for reviews. So far it looks like the 5770 might work in my Mac, but probably not 5870. Can anyone say if either of these would work in my MacPro Tower 3,1? Finally, the card I have now takes one video card plug slot (not sure exact terminology). I hear that most of the new ones take up two. Is that the difference between PCIe 1.0 and 2.0? Will the 5770 or 5780 fit in my one slot? I appreciate any advice/help. Thanks.