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Icaras

macrumors 603
Original poster
Mar 18, 2008
6,349
3,396
Ok, on the fence now for a new Mac Pro, but I don't seem to get a couple of things. I need someone to help me get a grip of the graphics card BTO options...

For example, I'd like to be able to, sometime down the road, expand to 3 displays for my work. That said, I'd like to get the HD 4870 for the extra graphics boost, but why can't I add a GT120 during customization? Is it due to hardware conflicts of having both an Nvidia and ATI card at once? If thats the case, why then, can't I add two HD 4780s to my machine, instead of multiple GT 120s???

But honestly speaking, I really don't need two two top of the line BTO cards. Which is why ideally, I'd like to spend less and just get a GT120 as my secondary card, but seeing as there are no BTO options for such a combination, my mind is boggled at the moment.
 
You were able to mix nVidia and ATi cards in the last generation, so I don't see why you can't in this one. Apple have never offered it on the website though, but you could order it over the phone.
 
You were able to mix nVidia and ATi cards in the last generation, so I don't see why you can't in this one. Apple have never offered it on the website though, but you could order it over the phone.

This distresses me.
 
So can anyone out there that can tell me why we're not allowed to have both cards at the same time when buying online? Or two 4780s at the same time?

Also, I'm currently running two 20" DVI Dell monitors. Does this mean I will need two graphics card to run both displays, or just one with some sort of dual link adapter?

:confused::confused::confused::confused:

Edit: Is it even advisable to mix and match these two cards? I'm very confused. Anyone else here planning on mixing and matching cards, or is it generally a good idea to have both of the same cards?
 
So can anyone out there that can tell me why we're not allowed to have both cards at the same time? Or two 4780s at the same time?

Also, I'm currently running two 20" DVI Dell monitors. Does this mean I will need two graphics card to run both displays, or just one with some sort of dual link adapter?

:confused::confused::confused::confused:

You can run your set up with one graphics card and a Mini DisplayPort to DVI adaptor.
 
A dual-link DVI port works in both dual link mode (ie: to drive 30" displays), or in single link mode (smaller displays up to 1920x1200).

As such, your pair of 20" displays (1680x1050) will work perfectly fine - one being driven by the dual-link DVI port (working in single link mode) and the other via the Mini DisplayPort with an adapter.
 
Thanks guys for the clarification!

Olly: yea, I said I have 20"s and that I had no experience with running a 30", which is why I was inquiring about the dual link DVI.

I wasn't sure if a standard DVI connector would fit or run at all in a dual link DVI, but I just learned it did.

Thank you :)

Anyway, I still plan on getting a triple display setup in the future and I still don't know why Apple would not allow you to add two 4870s, or one 4870 and a GT120 during customization. Even the product description of the soon to be released 4870 doesn't suggest having two of these for dual displays like the GT 120 description does.
 
Two 4870s DOES. NOT. WORK.

There are not neough power connectors, and the power draw would be too high.

I, personally, am getting a 4870 and a GT 120, so, yes, it is possible and yes, it works.

Ah, thanks tallest. Good to know. :)

I didn't go as far as to research the power draw, but I should have known if your getting a card of this caliber, its a must.
 
Does the 4870 require two 6-pin PCIe power taps? I don't know a whole lot about it or the specific model card 's had built to their specs; I'm just curious if it would be possible to run my 8800 GT and the 4870 simultaneously. I'm going to theorize that it's not, either due to power taps or total power draw. Also, because it seems like it would be just too simple for me to be able to do it that way, requiring me to replace my 8800 GT with a 2600 XT and the 4870 if I wanted to run 3+ monitors. What do you think, Skil?
 
Ugh. There go my nice, simple upgrade plans for getting a 4870. Even if I wanted to fork some more power off of the molex connectors...I don't think I could. I'm using both of them already for optical drives, though as an aside - can you split one that's split, then fork it off for 6-pin PCIe power? I'm guessing not. And that's assuming that the total power draw is under 300W anyway. I'm going go and guess that it isn't? Anybody who knows, do tell.
 
Ugh. There go my nice, simple upgrade plans for getting a 4870. Even if I wanted to fork some more power off of the molex connectors...I don't think I could. I'm using both of them already for optical drives, though as an aside - can you split one that's split, then fork it off for 6-pin PCIe power? I'm guessing not. And that's assuming that the total power draw is under 300W anyway. I'm going go and guess that it isn't? Anybody who knows, do tell.

You can attach a 6 pin PCIe power cable to a single 4 pin Molex connector. Whether it can supply the power is another story though, as it may not have adequate power, depending on what else is attached to the rails (+12V, +5V).

ATI gives a max power requirement of 225W. 75W of that is drawn directly from the slot, and the balance is split between the two 6 pin connectors (75W each).
 
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