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View Full Version : If MacPro is going to get Thunderbolt. How?




iSayuSay
Jan 26, 2012, 08:00 PM
Just out of curiosity I suddenly think. Assume MacPro line going to be updated sometime this year. Rest assured the line will get thunderbolt support along with the rest of Mac lines, complete the whole package.

But.. How do you think Apple would implement Thinderbolt on a MacPro? As you know, TB uses identical plug with DisplayPort, and MacPro feed video directly from GPU board to monitor. nVidia or AMD, they're both not licensed to use Thunderbolt technology on their graphic cards, are they?

Now with the thunderbolt on iMac or MBP with discrete GPU, yes... Apple also use AMD. But then again Thunderbolt/Displayport does not feed directly from GPU, right? It's connected to logic board and managed by Sandy Bridge CPU so it supports Thunderbolt, am I right?

So guys. How do you think a MacPro going to support TB port? On board? But video output on GPU card will be obsolete?



goMac
Jan 26, 2012, 09:49 PM
There are quite a few threads on this already. Nobody knows.

FrancoisC
Jan 26, 2012, 11:33 PM
There is a lot of possibilities…

One of them being that the Thunderbolt could be on the video card….

Another one would be to have the port on the Motherboarg/Logic board and have the video card send back it's video signal through the PCIe connection and back to the thunderbolt connection. Just has to make sure the delay is minimal, as in Ns and not Ms.

Another one (Which I have not read anywhere, just guessing here) could be a new specification included in PCIe 3.0, a "specialized" video feedback lane with 0 delay that connect directly to the thunderbolt port on the main board.


Anyway, I can't wait to see how it will be, which will be soon anyway, I read somewhere that PC motherboard will get thunderbolt this year.

thekev
Jan 26, 2012, 11:50 PM
Too many threads already exist on this, and they're all full of silly speculation. Consider that Intel mentioned it would be available on PCs this year too. If we see that happen, it should give some indication of how it could be implemented on a machine with discrete PCI cards. The thing that slightly annoyed me in the other threads was that someone would always inevitably state that Apple would probably sue the others for implementing thunderbolt when they don't even own the technology (and mini displayport is royalty free).

It was confirmed a while ago that it won't be a part of the Ivy Bridge chipsets.

deconstruct60
Jan 27, 2012, 01:09 PM
Consider that Intel mentioned it would be available on PCs this year too. If we see that happen, it should give some indication of how it could be implemented on a machine with discrete PCI cards.

That doesn't give any indication at all. The majority of PCs in general and Win PCs specifically ( as well as Macs ) are laptops + all-in-one designs. The limiting criteria Intel outlined last year was that the DisplayPort signal (and PCI-e signal) was on the motherboard with Thunderboard controller For laptops and machines with a GPU embedded, that is a non issue regardless of being Mac or not. Nor is this particularly a problem when the CPU package has a GPU in it ( which is increasingly the majority of the Intel and AMD line up).

Thrown in volume/thickness limited Ultrabooks (which limited space for ports) and Thunerbolt (TB) has even a stronger leverage and likelihood.

All of that still leaves discrete cards as a kludge unaligned with where the majority of the R&D dollars are being placed Intel, AMD, and system vendors. The industry is heading toward SoC (integrated functionality) architectures.


There are 3 broad categories.

1. Put an embedded GPU on the motherboard. (integrated GPU or mobile GPU boards designed to be embedded. )

Pros: just like all the rest of the Mac Line up.
decreases entry costs if can do without removable discrete card (e.g., server model).


Cons: sucks up probably at least 8-12 PCI-e lanes
increases base cost if also want discrete card


2. Internally route the DisplayPort (DP) signal down to the motherboard ( cable from DP connecters on card/board or non standard pin connectors. ).

Pros: Less strain on limited PCI-e lanes: same 16x PCI-e lanes used for graphics as non TB solution.

Cons: non standard cards (likely increased price , likely slow mainstream adoption rate).
Likely runs afoul of Apple's "no internal wires" design policy.
Potentially confusing functionality since card likely will still have DP connectors. (re-routed to another connector on box. )


3. Combo video cards.

Pros: simplified DP signal routing.

Cons: conflicting bandwidth and latency requirements between GPU and TB.
custom cards (increased costs, likely slow mainstream adoption rate. )


4. "Data only" TB. (Intel is going to intro a TB controller that can only do once channel (presumably data and probably chuck the DP handling so save on size/cost.). Port Ridge: http://arstechnica.com/gadgets/news/2011/09/upcoming-low-cost-thunderbolt-controller-could-broaden-reach-of-spec.ars )

Pros: Since decoupled from DP input, the video implementation doesn't matter.
Potentially 4x PCI-e TB "data only" cards for those that need it.


Cons: not due till later in the spring.
targeted to low cost, "end of TB chain" peripherals; not necessarily PC systems.
possible new connector ( since attaching to a port with 4 lanes seems huge overkill when can only use 1. Additionally, the confusion of "why doesn't my video work... the cable fits?" )

cube
Jan 27, 2012, 01:23 PM
I don't care how they add Thunderbolt, but the video cards should have DisplayPort 1.2 ports.

deconstruct60
Jan 27, 2012, 02:28 PM
I don't care how they add Thunderbolt, but the video cards should have DisplayPort 1.2 ports.

Oops that was a missing "cons" . That's is another conflict with adding them directly on the cards. Thunderbolt is not 1.2 aware/compatible. It is aimed at legacy transport not the current edge ( PCI-e v3.0 and DP 1.2 ).

ActionableMango
Jan 27, 2012, 03:10 PM
So I know DisplayPort 1.2 has a small throughput advantage over Thunderbolt, but what are the real-life benefits from that? IIRC, it's not enough of a speed difference to add another monitor on DP1.2 vs TB.

thekev
Jan 27, 2012, 05:41 PM
Oops that was a missing "cons" . That's is another conflict with adding them directly on the cards. Thunderbolt is not 1.2 aware/compatible. It is aimed at legacy transport not the current edge ( PCI-e v3.0 and DP 1.2 ).

I've read that Lion lacks support for displayport 1.2 as well (several times). I can't seem to verify it though.

deconstruct60
Jan 27, 2012, 05:54 PM
So I know DisplayPort 1.2 has a small throughput advantage over Thunderbolt, but what are the real-life benefits from that? IIRC, it's not enough of a speed difference to add another monitor on DP1.2 vs TB.

DP 1.2 allows

a. daisy chain monitors.
Right now I'm pretty sure that TB sends 1 DP signal down each physical port's chain. (IIRC there were problems trying to daisy chain TB monitors but could do two with an upper end iMac with two physical ports).


So far, not a big difference because few DP 1.2 chaining monitors. However, it somewhat mutes the TB 'feature' of multiple monitors.

[this is probably going to be a pain for TB because 1.2 has its own routing which will have to mesh with TB's physical layout. As opposed to the TB controller taking two separate 1.1 inputs and sending them where it determines they go. ]


b. stereoscopic 3D (somewhat a byproduct of a. but logically one screen. )

Probably not leaving many folks behind here, but a higher percentage on leading edge video cards.


c. increased color space (using added bandwidth).



d. Some AUX channel updates

Again not a big miss. In TB context those are better sent over PCI-e.



I think c is what will have the relatively biggest conflict with typical Mac Pro demographics. Not sure can do expanded (e.g. 10 bit ) color over DP 1.1a. Usually those monitors are dual-link DVI.

The issue isn't bandwidth (faster). It is what do you use the throughput to accomplish. DP 1.2 doesn't have the overhead of moving around PCI-e traffic so can spend the bandwidth on 3D and color. If you are working on a 3D or color problem, that is a better match. If really didn't care if there is video on TB anyway because primarily pumping SATA data then it isn't.



Thunderbolt is always going to trail PCI-e and DisplayPort unless those standards go comatose. TB is in a "lock up" period now where it can't move forward because it just came out. If PCI-e or DisplayPort come out with an update during this period then TB won't pick it up until the next update. With TB's next bandwidth update it will probably snag some DP 1.2 features.

iSayuSay
Jan 27, 2012, 07:02 PM
Thanks for some ideas & comments. I'm thinking about some alternatives:

1. TB port will be on MacPro logic board, but GPU still have the usual video outputs. This makes most sense to me, except for fact that it has the very same DisplayPort plug, which leads to confusion or awkwardness :D .. Should I plug my display to GPU? Or TB port? Or both?

2. TB port will be planted on GPU's logic board. Now this is a bit stranger. I'm thinking TB is not HDMI, which can be licensed to anyone, thus it can be found on any GPU cards today .. well at least not yet with TB, right? So yeah. I failed to see that nVidia or AMD going to get a license to make a Thunderbolt GPU. Especially AMD ... not .. gonna .. happen .. unless AMD put on a white flag, and pay up Intel a LOT of money and begging for TB? :D

But then again, the second alternative has its major drawback, yes? TB is not only for display, maybe user plug it along with data, HDD, SSD .. I think that will cause bad latency?

nutmac
Jan 27, 2012, 07:03 PM
I rather much see Mac Pro replaced with Thunderbolt Server (TS), essentially a headless box meant to be a docking station for MacBook Air or MacBook Pro (MB).

When connected to MB, TS adds CPU cores, memory, and storage. TS can also expand MB wirelessly, albeit at much slower speed and only for storage.

That said, I realize Thunderbolt's 10 Gbps falls short of top-of-the-line MP's 6.4 GT/s (25 Gbps) system bus. But I think benefits of this modular system can overweigh any theoretical deficiencies.

ActionableMango
Jan 27, 2012, 07:36 PM
I think c is what will have the relatively biggest conflict with typical Mac Pro demographics. Not sure can do expanded (e.g. 10 bit ) color over DP 1.1a.

Last I checked, OS X and/or its current video cards or drivers cannot do 10 bit color anyway. Here's the thread about it:
http://forums.macrumors.com/showthread.php?t=1235438

elvisizer
Jan 28, 2012, 02:33 PM
I rather much see Mac Pro replaced with Thunderbolt Server (TS), essentially a headless box meant to be a docking station for MacBook Air or MacBook Pro (MB).

When connected to MB, TS adds CPU cores, memory, and storage. TS can also expand MB wirelessly, albeit at much slower speed and only for storage.

That said, I realize Thunderbolt's 10 Gbps falls short of top-of-the-line MP's 6.4 GT/s (25 Gbps) system bus. But I think benefits of this modular system can overweigh any theoretical deficiencies.

10 Gbps vs 25 Gbps isn't a theoretical deficiency. if apple did this, i would not be happy. I'd rather they update the pro and add this as an additional product.

Cindori
Jan 28, 2012, 02:35 PM
thunderbolt on logic board for external storage

dp on gpu for display


is there really much more to it?

deconstruct60
Jan 28, 2012, 04:04 PM
Last I checked, OS X and/or its current video cards or drivers cannot do 10 bit color anyway. Here's the thread about it:
http://forums.macrumors.com/showthread.php?t=1235438

And it isn't going to get fixed by blowing away the standards that make interoperability easier. This is like saying Apple shouldn't put OpenGL 4.0 capable GPUs in the current Mac Pros because the legacy mode Mac OS X 10.6/10.7 is capped back at 1.2. ( http://developer.apple.com/graphicsimaging/opengl /capabilities/ ). And the current graphic core stuck at 3.0 (http://developer.apple.com/graphicsimaging/opengl/capabilities/GLInfo_1072_Core.html). It is silly. For hardware that is going to be used over the next 3-6 years you don't want to be capped to standards from the previous 3-5 years. All you are paying for is premature obsolesce and impeding the software development cycle.

TB is good at aggregating and transporting legacy data. Given that aspect of it, being backwards facing is fine. It is misdirected though at graphics card edges though that should be current and forward looking.

goMac
Jan 28, 2012, 06:08 PM
And it isn't going to get fixed by blowing away the standards that make interoperability easier. This is like saying Apple shouldn't put OpenGL 4.0 capable GPUs in the current Mac Pros because the legacy mode Mac OS X 10.6/10.7 is capped back at 1.2. ( http://developer.apple.com/graphicsimaging/opengl /capabilities/ ). And the current graphic core stuck at 3.0 (http://developer.apple.com/graphicsimaging/opengl/capabilities/GLInfo_1072_Core.html). It is silly. For hardware that is going to be used over the next 3-6 years you don't want to be capped to standards from the previous 3-5 years. All you are paying for is premature obsolesce and impeding the software development cycle.

It's not a problem on Apple's end. Apple's OpenGL implementation support 10 bit out, it's well documented in their OpenGL docs.

It's likely a driver issue on ATI or NVidia's end.

deconstruct60
Jan 28, 2012, 06:22 PM
It's not a problem on Apple's end. Apple's OpenGL implementation support 10 bit out, it's well documented in their OpenGL docs.

It's likely a driver issue on ATI or NVidia's end.

As you have stated before, there is a grey area between the Apple stack and the drivers that often requires both sides to get involved to solve the problem. Minimizing these grey areas with requirements from standards is a highly effective way of limiting the finger pointing and fog in resolving the bugs and issues.

iSayuSay
Jan 28, 2012, 07:24 PM
thunderbolt on logic board for external storage

dp on gpu for display


is there really much more to it?

Problem is TB using the same DP. So, by your concept .. can you connect monitor to TB on logic board? Or only from GPU? Or both? In reverse, can you connect TB storage to DP on GPU? TB supposed to work like USB + HDMI in one simple port, right? plus it offers higher transfer rate and bandwidth.

Things get simple in iMac, MacMini or MBP/MBA, but I think it's a bit complicated on MacPro since video feed usually come direct from GPU, just like PC desktop. Or Apple could make a custom MacPro GPU card with no video output, so everything coming out off onboard TB? It's possible, coming from  .. so yeah I think it could be much more to it.

goMac
Jan 28, 2012, 07:28 PM
On the other hand, whatever the fate of the Mac Pro, it's an issue Intel has to work out anyway for desktop PCs. It's not just a Mac Pro issue, which is why I think we'll eventually see a solution.

deconstruct60
Jan 28, 2012, 08:47 PM
Problem is TB using the same DP. So, by your concept .. can you connect monitor to TB on logic board?

First, there is nothing in what he stated that precludes there being only one GPU inside the Mac Pro. An embedded GPU would provide video if users wanted it but it is not the video from the card.

Second, if render the port "data only" and Intel and Apple introduce a new connector for "data only" TB then you won't be able to connect it. Or at least, users would be overtly overlooking the mismatch.

But yes, if they don't introduce a new interface for the new functionality, this introduces a "transparency to usage" problem that is very un-Apple like. This port with the same markings , labels , shape, etc. behaves different on one Mac than it does on the others. Users are suppose to look at the other ports on the device to determine whether it should or should not produce video.

It is a much simpler solution to require that computers with Thunderbolt must produce video. That's the likely restriction from putting TB on "add-in" PCI-e cards that Intel has enforced so far.




Or only from GPU?


No the TB display is a docking station that integrates a monitor in it. Most in search of something that is primarily a monitor will buy a monitor with a variety of video connectors on them. Apple doesn't sell those anymore.



Or both?


No. TB displays don't work on DP only ports. The motivation to put DP connectors on the GPU card is to maximize compatibility with the displays on the market. This isn't a "tail wags the dog" where primarily have to push sales of TB Display.




Things get simple in iMac, MacMini or MBP/MBA, but I think it's a bit complicated on MacPro since video feed usually come direct from GPU, just like PC desktop.

Video feed comes from the GPU on the iMac, Mini, MBP/MBA and some Windows PCs too. The difference is that GPU in the Mac Pro is more easily removed/replaced.

If made a Mac Pro where video couldn't be easily removed/replaced that would eliminate the difference.

----------

... it's an issue Intel has to work out anyway for desktop PCs. It's not just a Mac Pro issue, which is why I think we'll eventually see a solution.

They already are. They are adding GPUs to CPU packages as fast as they can. The only reason this is an issue is that it is possible to remove the GPU from the box. Remove that issue and the problem is gone. A rapidly rise percentage if even the "boxes with slots" in the general PC market already do have a GPU on the motherboard inside the CPU package.

kinezu
Feb 2, 2012, 09:10 AM
I think the new Mac Pro's will come with an integrated Intel video card which will process the video and TB ports in front and back and if you want extra GPU power, the cards will be optional. Remeber, TB ports have the lightning sign on them and DP ports have only a display sign on them so i think there's no confusion. Apple always plan to lower the energy consuption generation over generation so the integrated chipset is the logical choice.