Re: Does This Kill The Mac Pro?

[Jeremy Garchow] " "I see Thunderbolt as forcing Apple to drop PCIe... And PCIe is the reason people buy Mac Pros."

But thunderbolt is part pcie, so how and why would apple drop pcie?"

I miss typed. I meant to say PCIe slots.


Here's a very long explanation of my logic:

You can't change the GPU because the Display Port signal output from the GPU needs to be sent to the Thunderbolt controller. There are only three ways to do this, and apple is very, very unlucky to chose two of them.

1) A built in, non-replaceable GPU. This is how all other Thunderbolt equipped Mac's work. The output from the GPU is sent to the Thunderbolt controller across the circuit board.

2) A Custom PCIe 16x GPU with Thunderbolt ports instead of regular Display Port connectors or DVI connectors. Basically, Apple would take an ordinary ATI GPU card and stick thunderbolt controller chips on it. They'd get their Display Port signal from the ATI GPU and their PCIe connection and feed it all out together. Unfortunately this would limit the speed of the GPU cause the Thunderbolt Controller would be using at least 1/4 of the 16x PCIe connection.

3a) A slight variation on #2, except that the custom GPU would feed it's Display signal along an internal Display port cable to a Thunderbolt controller somewhere on the Mother board. In this case the GPU card would have no ports on the outside of the computer.

3b) same as 3a, but ordinary GPU is used and the PCIe 16x is moved so that the GPU card is completely contained within the Mac. This way the Display Port cable(s) which drive the THunderbolt controller can be plugged into the normal GPU without exiting the computer.


Those are the possibilities.

Number 3b would be the best for us, as it would allow all current Display Port GPU's to work.

Number 3a would be ok, but new GPU's would have to be made, so our options would be limited for a while, since all current GPUs wouldn't work with Thunderbolt. (It's posible that Apple would let you use a normal GPU, there by leaving you with THunderbolt ports that serve data but not display information.)

NUmber 2 would also be limiting to us as we'd have to wait for new GPU options as the old ones wouldn't work with Thunderbolt.
(Again ok if apple lets us use old GPU's)

Number 1 of course would mean no user replaceable GPU.

How likely are each of these?

Well, I'd say that number 1 is likely,

Number 2, while perhaps a great way to get thunderbolt ports on Windows computers, it is totally Un-apple, (I'm sure they want a Thunderbolt port on the front as well as the back, and this option wouldn't allow that. Also, this would be limited to two thunderbolt ports.) and so I rate that one Very, Very unlikely.

Number 3a would be great, and the most likely choice if apple realizes how much we pros need to be able to swap out GPUs and other things.

Number 3b is unlikely because it would require a redesign and I strongly doubt that Apple wouldn't redesign the Mac Pro so as to be able to continue offering PCIe slots. I believe that any redesign of the Mac Pro will be Thunderbolt centric and and redesigning the Mac Pro to offer option 3b would be un Apple as that wouldn't be forward thinking and they'd just have to redesign the Mac Pro again as soon as 100Gb Thunderbolt comes out. Simply put, option 3b requires an extra redesign before apple goes all Thunderbolt.

Keeping PCIe Slots at all also requires an extra redesign before the Mac Pro goes all thunderbolt, and that's why I said before that I believe that Apple is far more likely to keep the current design until they dump PCIe slots all together.

So the question is, when will that be?

Well, if Apple has any love for us pros that won't be until 100Gb thunderbolt comes along.
But if the fact that rumors of a small Mac Pro have been going around for months, I think at least a partial dropping of PCIe slots is in order.

Unless they have 100Gb Thunderbolt up their sleeves for the upcoming refresh, They'd better chose Option 3a or we're all going to be stuck for a few years.