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canadave · Jan 13, 2008, 02:16 PM

Hi all,

I'm soon going to be taking the plunge from the PC world into Macdom with a new Mac Pro on the way. I got the standard configuration with the ATI 2600 card, but at some point, I'm going to be getting another video card to use for occasional Windows gaming in Boot Camp--hopefully an nVidia 8800.

My question is, once I get that setup going, how exactly do I hook that up for use with two monitors in extended mode? One monitor has a DVI in, the other has an HDMI in, and both have a VGA in. I assume I need some sort of switch, but my head's beginning to hurt thinking about the various cable ins and outs and routes. Also, I'm hoping not to spend hundreds of dollars on such a switch...the cheaper and simpler the better (the wife is already just about ready to mutiny after spending almost $3,000 on the Mac Pro itself).

Does anyone have any ideas/recommendations on this score?

Thanks,
Dave

mduell · Jan 13, 2008, 04:07 PM

More information is needed. The possibilities range from free to expensive.

Do you need to be able to map an arbitrary video output (there are 4 video outputs here, two on each card) to an arbitrary display? This is the most expensive way to go. Another way of asking this is will one display always be your primary display while the other is always your secondary display? Or do you need to be able to switch where the dock/menu bar and taskbar appear?
Do you want the displays to always mirror each other? That is, to have the same image be displayed on both.
How sensitive are you to image quality compared to price? In other words, is a marginal difference in quality worth $200?

canadave · Jan 13, 2008, 07:17 PM

Thanks for the reply.

I should've been clearer, sorry. One of the monitors as a primary is fine; I don't need the capability to switch the primary monitor. Basically I just want to be able to use a second monitor to expand my workspace (I'm a freelance editor and would like to be able to work on two documents at once, one in each screen). The monitors are both about the same size (well, one is an LCD TV, but, other than that they're the same size).

I would also like to use two monitors to extend the viewing area for Windows games in Boot Camp, down the road at some point (i.e. for Flight Simulator or something like that).

As for marginal increases in quality: if your question has to do with DVI versus VGA, I suppose I would be fine with VGA...although I've never seen a DVI display (I feel so old), so I have no visual reference in my mind to compare. I'd like to go fully DVI if possible, but if it's quite a bit more money, I can settle for VGA.

--Dave

Tesselator · Jan 13, 2008, 08:09 PM

Do not use an external monitor switch. They often degrade horribly the signal quality that the monitors receive.
I've had quite a few and nearly all of them were unacceptable. Use the switch on the monitor itself. So for instance
hook the PC up to the two 15pin RGB inputs with the "main" monitor (w/taskbar) on the Left and connect up the
mac to the DVI and HDMI of each with the main monitor (w/dock) on the right. This will allow you to go dual on
your PC or Mac if you want and also allow you to use both at once.

mduell · Jan 13, 2008, 09:09 PM

Originally Posted by canadave

I should've been clearer, sorry. One of the monitors as a primary is fine; I don't need the capability to switch the primary monitor. Basically I just want to be able to use a second monitor to expand my workspace (I'm a freelance editor and would like to be able to work on two documents at once, one in each screen). The monitors are both about the same size (well, one is an LCD TV, but, other than that they're the same size).

I would also like to use two monitors to extend the viewing area for Windows games in Boot Camp, down the road at some point (i.e. for Flight Simulator or something like that).

As for marginal increases in quality: if your question has to do with DVI versus VGA, I suppose I would be fine with VGA...although I've never seen a DVI display (I feel so old), so I have no visual reference in my mind to compare. I'd like to go fully DVI if possible, but if it's quite a bit more money, I can settle for VGA.

An $80 KVM will do it for you (happens to be cheaper than a DVI switch). If you don't need the second display in Windows, you can just buy one.

The free way is to just plug each display into DVI on one video card and VGA on the other, so you'd have DVI in OSX and VGA in Windows.

As Tesselator mentioned, you can't go cheap with VGA switches; fortunately DVI isn't as sensitive.

canadave · Jan 13, 2008, 09:58 PM

OK, I'm more confused than ever

@Tesselator: thanks, but your reply seemed to be about hooking up a PC and a Mac. I only have the Mac I want to hook up to the two monitors; in the situation I'm thinking of, that Mac would have two video cards...one for use in Mac OSX, and one for use with Windows in Boot Camp.

@mduell: thanks for the link; so I basically need some sort of 2x2 switch (whether DVI-only or KVM)? I want to keep the single keyboard and mouse...that shouldn't make a difference given that all I want to do is switch video cards depending on whether I'm in OSX or Windows, right? It's all on the same computer. I'm not sure what you mean, though, when you said "if you don't need the second display in Windows, you can just buy one." I do need the 2nd display in Windows (for extending the display in games...like, Flight Simulator can show the forward view and side view, each on a different monitor. I'm not sure how that makes a difference in terms of what to buy?.....

However your point about the DVI and VGA is totally clear....I guess I could go that route if I got the appropriate cables.

Thanks for your help!
Dave

mduell · Jan 14, 2008, 06:54 AM

Originally Posted by canadave

@Tesselator: thanks, but your reply seemed to be about hooking up a PC and a Mac. I only have the Mac I want to hook up to the two monitors; in the situation I'm thinking of, that Mac would have two video cards...one for use in Mac OSX, and one for use with Windows in Boot Camp.

Hooking up two computers to one display and hooking up two video cards to one display is pretty much the same thing.

Originally Posted by canadave

@mduell: thanks for the link; so I basically need some sort of 2x2 switch (whether DVI-only or KVM)? I want to keep the single keyboard and mouse...that shouldn't make a difference given that all I want to do is switch video cards depending on whether I'm in OSX or Windows, right? It's all on the same computer. I'm not sure what you mean, though, when you said "if you don't need the second display in Windows, you can just buy one." I do need the 2nd display in Windows (for extending the display in games...like, Flight Simulator can show the forward view and side view, each on a different monitor. I'm not sure how that makes a difference in terms of what to buy?.....

Buy two of the switches I linked to. One will be used for your computer monitor and one will be used for your TV.

Buy a DVI to HDMI cable so you can connect your TV to one of the switches; you should already have a DVI cable for your monitor, but if not buy one of those too.

You only have one keyboard/mouse to use because you only have one computer.

frdmfghtr · Jan 14, 2008, 07:28 AM

This all sounds very confusing. Why switch video cards depending on the OS you are using? If/when you get the 8800, use that as your primary card in OS X and Windows with the better monitor as the primary, driving the secondary display with the 2600.

Seems to me that this would make everything a while lot easier, but I may be missing something.

eggman · Jan 14, 2008, 07:51 AM

Originally Posted by frdmfghtr

This all sounds very confusing. Why switch video cards depending on the OS you are using? If/when you get the 8800, use that as your primary card in OS X and Windows with the better monitor as the primary, driving the secondary display with the 2600.

Seems to me that this would make everything a while lot easier, but I may be missing something.

For that matter, the 8800 can drive both monitors. Sell the 2600, or keep it as a backup in case of a meltdown of the 8800. (I'm damn glad I hung on to my Dual G5's stock video card when I upgraded it with the ATI x800 which failed months later... so I had use of my system while getting the warrantee repair).

Simon · Jan 14, 2008, 08:10 AM

Originally Posted by eggman

For that matter, the 8800 can drive both monitors.

Actually the 8800GT and the 2600XT both come with two DDL DVI ports. So each cards can drive two 30" displays by itself.

Tesselator · Jan 14, 2008, 08:56 AM

Originally Posted by canadave

OK, I'm more confused than ever

Thanks for your help!
Dave

mdeull answered it for me. (thanks mdeull!) but the most important point to sponge from my info is
mostly just that KVMs and switches will degrade your image quality and very often so badly that the
resulting image will be unacceptable.

Just make sure that the shop you get it from will allow you to return it if it sucks.

eggman · Jan 14, 2008, 03:46 PM

Originally Posted by Simon

Actually the 8800GT and the 2600XT both come with two DDL DVI ports. So each cards can drive two 30" displays by itself.

Isn't that precisely what I was saying?

mduell · Jan 14, 2008, 04:59 PM

Originally Posted by frdmfghtr

This all sounds very confusing. Why switch video cards depending on the OS you are using? If/when you get the 8800, use that as your primary card in OS X and Windows with the better monitor as the primary, driving the secondary display with the 2600.

Originally Posted by eggman

For that matter, the 8800 can drive both monitors. Sell the 2600, or keep it as a backup in case of a meltdown of the 8800. (I'm damn glad I hung on to my Dual G5's stock video card when I upgraded it with the ATI x800 which failed months later... so I had use of my system while getting the warrantee repair).

As he said in his first post, he's going to buy a cheap COTS 8800GT that won't work with OS X: "I'm going to be getting another video card to use for occasional Windows gaming in Boot Camp--hopefully an nVidia 8800."

eggman · Jan 14, 2008, 05:07 PM

Originally Posted by mduell

As he said in his first post, he's going to buy a cheap COTS 8800GT that won't work with OS X: "I'm going to be getting another video card to use for occasional Windows gaming in Boot Camp--hopefully an nVidia 8800."

<emily_litella >Oh. Never Mind!</emily_litella >

Simon · Jan 15, 2008, 02:37 AM

Originally Posted by eggman

Isn't that precisely what I was saying?

Oh well, seems like it's just a little misunderstanding. To me your post sounded like you were telling him to get an 8800GT to be able to drive two displays off of one card. I simply wanted to point out that you can already do that with the stock 2600XT. No worries.