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Wow- each Thunderbolt port under a separate bus/controller? That's huge! So when I plug in to one port, I don't worry about reducing the bandwidth on a neighboring port? These ports aren't shared the way they were on my Mac Pro (2013) cylinder? These are each full-bore 40 Gbs ports? I don't need an "active cable" or "active adapter' to get full 40 Gbs? Like from a Thunderbolt 3 RAID?
The Apple specs are not clear to me on this.
Best as always,
Loren
<< So when I plug in to one port, I don't worry about reducing the bandwidth on a neighboring port? >>
<< These ports aren't shared the way they were on my Mac Pro (2013) cylinder? >>
<< These are each full-bore 40 Gbs ports? >>
all of the above are accurate as written.
There was another discussion suggesting that when connecting two high-end displays, you should stagger which ports you plug them into, if you can. That is NOT due to bandwidth limitations.
That is because it will allow the ThunderBolt controller chips (each of which controls two independent 40 G Bytes/sec ThunderBolt ports) to not get quite so hot.
<< So when I plug in to one port, I don't worry about reducing the bandwidth on a neighboring port? >>
<< These ports aren't shared the way they were on my Mac Pro (2013) cylinder? >>
<< These are each full-bore 40 Gbs ports? >>
all of the above are accurate as written.
There was another discussion suggesting that when connecting two high-end displays, you should stagger which ports you plug them into, if you can. That is NOT due to bandwidth limitations.
That is because it will allow the ThunderBolt controller chips (each of which controls two independent 40 G Bytes/sec ThunderBolt ports) to not get quite so hot.
In my opinion, your other two Busses were not "out of gas" supporting RAID arrays either, especially if they were not built from fast SSD drives. You should have been able to run a RAID array from ANY port on any bus, and even run your two RAID arrays on the same ThunderBolt bus with no slowdowns.
The three Thunderbolt-2 Busses on your Mac Pro 2103 are 20 G Bytes/sec busses, with two ports. But nothing you have mentioned EXCEPT the 4K display requires near that much bandwidth.
Why is that a "Wow"? I'm deciding nothing, my friend. I'm asking. There are three Thunderbolt busses on the Mac Pro model 6,1. The schema was published some time ago on Apple's site. That's my only frame of reference.
Just to echo what I learned:
Thunderbolt 2 ports, "Up to 20 Gbs."
Buss 2- top two pairs
Buss 1- middle two pairs
Buss 0- bottom two pairs PLUS HDMI port
I assigned buss 2 to one of my RAID boxes, leaving the other port unused, to enjoy full bandwidth.
Same with buss 1, my second RAID box (OWC ThunderBay 4, stepped down from Tbolt 3 to 2.) Second port unused. I get nearly top speed from both, enough to edit 2 streams of 4K ProRes 422 (HQ).
Buss 0 shares a pair of HD Acer monitors-- no problems.
But I got no signal through the HDMI port shared with this pair when trying to light up my 27" 4K LG client monitor.
Had to buy an"active adapter" and that went through the empty Buss 1 Thunderbolt port. It works, but has to build up power for a few seconds to light it when booting. Then it's beautiful. I'll be keeping the cylinder as second machine. Nothing is plugged into the HDMI port. Not enough juice, apparently.
Now I'm seeing a similar port layout on Mac Studio M1 Ultra. So naturally, I decide to ask questions.
I'm using the terms "buss" and "controller" not because I'm deciding anything- I'm a film editor running a small shop, not a Level 10 engineer with hundreds of thousands of points -- because I've heard both terms related to port bandwidth-- in fact, it was a recent Reddit discussion about the Mac Studio port layout: somebody had already asked the same question about port busses and the same concern about less-than-rated bandwidth when two devices are plugged into ports on a supposedly shared buss. A discussant chimed in with something new - I'm paraphrasing-- "actually, it's less about busses, and more about controllers on the chip." So aiming to expand my consciousness and plan my desktop, I'm throwing these terms against the wall to see how well they stick.
So are the Tbolt ports shared in any way, via buss or controller path? Or are they really discrete 40 Gbs, unsullied all the way down?
Thanks for your patience! I'll take any wisdom you care to offer, and I'll share it with credit.
Best as always,
Loren
So I launched System Report on my Studio Max and it shows 4 Thunderbolt busses for the four rear ports, each showing 40Gb/s X1. The Studio Ultra has two more TB4 ports on the front. I suggest you launch System Report and see what it says for your Ultra.
System Settings->General->About->System Report->Thunderbolt/USB4
Regarding ports for displays:
The reason the HDMI port on the Mac Pro 2013 can not support your 4K display at 60 Hz is that it is only HDMI 1.4, which can only run 4K at 30 Hz, because of limitations of HDMI. That has nothing to do with limitations of ThunderBolt. That Bus was not "out of gas" supporting your other two displays.
If you use a high-end adapter to generate HDMI 2 from a ThunderBolt port instead, you get your 4K display supported at 60 Hz.
Mac mini 2018, Mac Pro 2019, MacBook Pro 2021 and later, and Mac Studio all feature HDMI 2.0, which can run 4K at 60 Hz.
Grant-
But my two cheap Acers are only HD 60 hz, so they should be fine, yes?
Thanks for ALL the detail- I got the port numbers wrong on my cylinder. But everything you say tracks.
The reason haven't gone to NVMe RAID arrays has to do with long term storage. HDD drives last longer on the shelf without being powered. That's important as I explored the RAID set archive process, chronicled at link below.
Best as always,
Loren
<< each Thunderbolt port under a separate bus/controller >>
¿How did you decide that?
I thought I was clear- it was a question! Does any Thunderbolt port on Studio Ultra share bandwidth with another Thunderbolt port- as they do on my aging Mac Pro 2013?
Best as always,
Loren
<< share bandwidth with another Thunderbolt port - as they do on my aging Mac Pro 2013? >>
Wow, How did you decide THAT ??
Thunderbolt busses revisited for clarity
