Mac Pro 3.1 + ATI 5770 + 2 Displays

THIS: http://support.apple.com/kb/HT4279

Whether you want to keep using the 8800GT.... or just keep it out before it needs to be baked.

Only comment is you are already running 10.6.5 or later, right... and not sure about 15 ft (Dr Bott is where I would look for one) should be doable

That article was: Mac Pro (Early 2009), Mac Pro (Mid 2010):

The 5770 (check product page and well, it works on any Mac Pro from feedback etc) works just fine in PCIe 2.0 slot to full advantage. There is a lack of audio and something about HDCP (maybe).

And this about pre-2010:

http://support.apple.com/kb/TS3891

I wish they would have a www.apple.com/support/5770 or links on the product page with alll releated articles in one place rather than have to hunt them out.

I use to run VGA monitor about 25 ft but not DVI.

I'm planning to add another Display, the new LED 27 and the ATI Radeon 5770 graphic card.

If you do this make sure you get the older mini-displayport version of the 27" (still sold by apple) and not the current Thunderbolt model.

Also the apple version of the 5770.

Note that the 5770 card requires one aux power adapter cable (I think it comes with the card).

The 5770 can handle both monitors with no problem.

Just plug the 27" into the 5770's mini-displayport and the 23" into the DVI port and you are good to go (may have to play wth the Displays system prefs a little bit to get the arrangement the way you want). Or just keep the 23" in your older card.

so I'll take a 15 feet cable DVI-D dual link male to female.

Will this cause issue?

Don't think so. Monoprice.com sells 15' DVI cables and the comments about it have no complaints about problems with it. You could always choose to use the thicker (and stiffer) 24AWG instead of the 28AWG if you have any concerns.

I have a Mac Pro 3,1 (early 2008), dual quad core, with 16 GB RAM. My machine came with the ATI HD 2600 and I have since added the Apple-branded ATI 5770; I put the ATI 5770 in the first PCIe slot (it's the only double width slot), and the 2600 in slot 2.

I have two displays, both use DVI connectors. One display is connected to each of my two display cards.

This works, but there is a definite gotcha:

I have been unable to successfully add a eSATA or USB3 card to PCIe slot 3 or 4. When I do, I get intermittant display problems, or problems with waking my system from sleep (it doesn't always wake up). The display problems only occur on the display connected to the 5770, and can be snow on the screen, or the display flashing on and off. The problem usually occurs when the computer wakes from sleep. The problems occur in both Mac OS (Lion 10.7.3) or Windows 7 (Bootcamp). they are intermittant. I have tried 2 different Mac compatible USB 3 cards, as well as a Mac compatible eSATA card, all had issues. And, I replaced the 5770, to no avail.

I conclude that although the ATI 5770 works in the early 2008 Mac 2008, there are problems - probably there isn't quite enough power available on the PCIe bus. When I try to add a third card (the USB3 or eSATA card), things go awry. I would guess that's why the 5770 card isn't officially supported by Apple.

So, I would be a bit leary of putting two display cards in the early 2008 Mac Pro, if it can be avoided. I will probably get rid of my 2600 card, and connect both my displays to the 5770 (I'll have to use a mini display port to DVI adapter cable, but they are cheap).

And, at the risk of partially hijacking the thread - does anyone know any problems with using two displays on the 5770? Will graphics performance degrade?

I said in my previous reply that the 5770 card can handle two displays with no problems. It can also handle three displays as well but then you need two active adapters.

I might be able to add some helpful info:

My System:

Mac Pro 3,1 (2008) / 2.8 GHz 8-core, Mac OS X (10.7), 24 GB RAM / ATI Radeon 4870 + 5770

My Displays:

Apple Cinema Display: 30-inch — paired w/ ATI Radeon HD 5770

Apple Cinema Display: 23-inch (x2) — paired w/ ATI Radeon HD 4870 (flashed w/ Apple firmware)

PCI - slot 1: 5770

PCI - slot 2: 4870

PCI - slot 3: ununsed / covered by 4870 (b/c it's thick)

PCI - slot 4: eSATA controller

Unlike alexofindy, I've been able to succesfully use an eSATA controller in PCI slot 4. I have two docks—each with a 3.5" hard drive—connected to the eSATA card, and that works just fine. Based on that, I think his conclusion that "there isn't quite enough power available on the PCIe bus" for the 5770 is incorrect. I'm not sure why he's having problems, but one obvious suspect would seem to be his other video card (ATI HD 2600), since that seems to be the main difference between his system and mine.

I know nothing about that card, but I should mention my power connections for my cards (5770 / 4870) in case that's helpful to anyone. The 5770 requires only one power connection, but the 4870 requires two. There are only two (easily accessible) power connections on the logic board, so I had to purchase a Y-cable (splitter) in order to turn those two connections into three. Based on a tip I read online, instead of connecting both ends of the Y-split cable to the 4870, I connected one to the 5770 and one to the 4870. I used the standard (non-split) cable for the second connection on the 4870. This may or may not be relevant—I've never tried it the other way—but I can say that it works. (The theory, I suppose, is that the Y-split cable may not provide twice the power, so rather than channeling both potentially-deficient power sources to the same card, this arrangment dilutes the potential weakness by dividing it between both cards.)

alexofindy said, "I would guess that's why the 5770 card isn't officially supported by Apple." I don't know, but I've heard another theory that makes more sense to me—which is that Apple doesn't officially support it because it wasn't in existence when the Mac Pro 3,1 was introduced. Thus, if a user were to wipe and reinstall the system using the factory installation discs, he would have no way of getting a video signal to a display running off the 5770 without first performing some software updates (which would be hard to accomplish without a display!)

Anyway... I hope this helps provide some valuable info.

-Jason

alexofindy: "...does anyone know any problems with using two displays on the 5770? Will graphics performance degrade?"

As I understand it, the VRAM of a video card—1GB in the case of the 5770—is shared between all the displays to which it is connected. That's why I have my 5770 running only to one display (my 30-inch Apple Cinema Display). I want all the VRAM I can get for my main display because that's the display on which I run Photoshop. Even though I could connect all three of my displays to that one card (I think)—2 via DVI and 1 via MDP—I don't want to dilute that available VRAM by sharing it among multiple displays.

So, "problems"?—not really... but "repercussions?"—yes/potentially (depending on your usage)

Thanks very much for the posts, particularly Jason for his extensive responses.

I'm going to stick with my unproven theory that at least on my system there's a power issue on the PCIe bus. Since the 2600 card I use as my second display card does not use an auxilliary power cable (unlike the 5770 and the 4870) and therefore gets all its power from the PCIe bus, it may stress the bus power more on my setup than Jason's.

But who knows. I do have a recent vintage 2600 - Apple had an extended warranty on the 2600 so I also replaced it at no cost to me, and I don't think I have a bad 2600, but I can't be sure. And, as I mentioned, I just replaced the 5770 to no avail.

It may be that I have a defect (perhaps a wimpy power supply) that other systems don't suffer from. Since I am, of course, off Apple Care, and since the problem is intermittant, and therefore would be hard to trouble shoot, I'm going to have to live with it.

Per Jason's comment, I'm going to leave my two display cards in, and the eSATA out. I use an ethernet connected NAS for most of my auxilliary storage, and only had occasional need for the eSATA. I'll have to make do with USB-2 when I need an external drive.

Thanks to all, and good luck to the original poster.