MP 7,1 Question about the IO Card & TB3 Bandwidth

[mattfezz]

Hi, I am just wondering if the apple IO card in a PCI express 4x slot would have enough bandwidth for thunderbolt 3 maxed @40Gb/s (I am guessing that it is just one bus)

Would there be any benefit from moving the card to an 8x slot?

 

[deconstruct60]

Hi, I am just wondering if the apple IO card in a PCI express 4x slot would have enough bandwidth for thunderbolt 3 maxed @40Gb/s (I am guessing that it is just one bus)

Would there be any benefit from moving the card to an 8x slot?

The Thunderbolt controller present on the card only have a x4 PCI-e connection on it. You can't pump more than x4 PCI-e through a controller.

Thunderbolt data is not PCI-e data. That don't match. Not suppose to match. Thunderbolt transports other formats, so needs to be faster than what sending.

 

[krakman]

I wonder if the Apple IO card would work in the 5.1 ???? It might be a simple way to add thunderbolt to the old machine, but the problem would be getting hold of the card on its own from Apple.

 

[bsbeamer]

I wonder if the Apple IO card would work in the 5.1 ???? It might be a simple way to add thunderbolt to the old machine, but the problem would be getting hold of the card on its own from Apple.

There was speculation that it MIGHT work. Maybe one of the early adopters who has an MP5,1 and is already on Catalina via the non-DosDude hack methods can give it a shot and let us know.

I'm sure it could be picked up as a spare part. Apple's own documentation shows how to replace it:
https://support.apple.com/en-us/HT210570

 

[shokunin]

According to Apple, the IO card can only be in slot 8 (top Half length slot) and can’t be moved to another PCIe slot.

 

[crw]

According to Apple, the IO card can only be in slot 8 (top Half length slot) and can’t be moved to another PCIe slot.

I believe Apple has added a proprietary interface to this slot that routes DisplayPort video. This is what enables the TB3 ports to display the video from MPX cards. Because it requires this proprietary interface the card can not work in other slots (or older Mac Pros).

 

[goMac]

I believe Apple has added a proprietary interface to this slot that routes DisplayPort video. This is what enables the TB3 ports to display the video from MPX cards. Because it requires this proprietary interface the card can not work in other slots (or older Mac Pros).

This.

The Apple I/O card is a proprietary card type. It requires a special slot. The slot that Apple installs it in can be used as a PCIe slot, but it's not a normal slot.

This means you can't move the Apple I/O card to another slot, you can't install multiple, and it very likely won't do anything in an older Mac Pro, even if it can physically be installed.

 

[deconstruct60]

I believe Apple has added a proprietary interface to this slot that routes DisplayPort video.

Probably GPIO also. Since it probably can handle live plug and play events and Thunderbolt network reconfiguration events ( unlike the hacks on the MP 5,1 ).

This is what enables the TB3 ports to display the video from MPX cards. Because it requires this proprietary interface the card can not work in other slots (or older Mac Pros).

I think they may have used the PCI-e pins for something other than PCI-e . IF you plug it into a regular PCI-e slot that slot will take those for PCI-e and at best quirky things would happen. If Apple went down that path then the prudent thing to do is set up the card firmware to just 'quit' if senses someone plugged it into the wrong slot.

Better thing would have some physical notch displacement so just can't plug it in 'properly'. There are enough hackery card options out there that Apple doesn't need to pile this card on top. But I think they wanted the option to put standard PCI-e x4 cards in there so I don't think there is a physical block for that. ( possibly opens door for bad things if someone tries to put in some bigger than x4 in there. ).

I think it is removable because some folks blow out USB sockets ( and maybe some Thunderbolt sockets ) with cheesy implemented power options plugged in. If you blow out a socket then it is a simple board replacement.

There also may be a "certified USB4" option coming later too. Won't need any more bandwidth feeds than what they have now. I suspect that is a bigger driver (especially if they plan to disappear for 2-3+ years again ) .