Chris Harlan
Forum Replies Created
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[Chris Kenny] “[Chris Harlan] “This makes sense to me as these would be extensions of a PCIe lane, and is why I’m doubtful that you’ll ever see a hub, other than hubs for other protocols.”
PCIe supports star topologies itself — that’s how external PCIe expander boxes like the Magma work. And in any event, Thunderbolt isn’t quite native PCIe — PCIe is just one protocol that can be multiplexed over it. Even if PCIe didn’t support star topologies, Thunderbolt controllers could disguise what was going on from PCIe devices.
“Again, I think you’re mistaken and are mixing up abstraction layers. I’d like to be wrong. I’d like a hub. The one thing I know you are mistaken about in the above paragraph is “PCIe is just one protocol that can be multiplexed over it.” PCIe and DisplayPort are the ONLY two bus level protocols muxed by Thunderbolt at that abstraction layer. Other protocols run on top of them. In my searches, I’ve found many references to hubs or potential hubs for upper level protocols, but NONE for anything at that level. ALL references at that level are to daisy-chaining. Check out the following Intel brief. Notice the focus on the daisy chain as the mode of connection.
https://www.intel.com/content/dam/doc/technology-brief/thunderbolt-technology-brief.pdf
“With Thunderbolt products, performance, simplicity and flexibility all come together. Users can add high-performance features to their PC over a cable, daisy chaining one after another, up to a total of 7 devices, 1 or 2 of which can be high-resolution DisplayPort v1.1a displays (depending on the controller configuration in the host PC). Because Thunderbolt technology delivers two full-bandwidth channels, the user can realize high bandwidth on not only the first device attached, but on downstream devices as well.
Users can always connect to their other non-Thunderbolt products at the end of a daisy chain by using Thunderbolt technology adapters (e.g., to connect to native PCI Express devices like eSata, Firewire). These adapters can be easily built using a Thunderbolt controller with off-the-shelf PCI Express-to-“other technology” controllers.” -
[Chris Kenny] “[Chris Harlan] “I don’t believe thats the case. I could be wrong, but I believe the nature of Thunderbolt requires a single chain like SCSI.”
https://www.intel.com/content/dam/doc/technology-brief/thunderbolt-technolog...
“A symmetric architecture that supports flexible topologies (star, tree, daisy chaining, etc.) and enables peer-to-peer communication (via software) between devices.”
Star/tree topologies should allow for hubs.
FireWire technically allows for hubs as well. A few were available, but they were never very popular.
“Chris, I interpret this differently than you do. I think you are talking Apples and Oranges, here. But, as I say, I may be wrong. This is my understanding. I believe the “symmetric architecture” alluded to in this brochure exists on the Transport Layer (Apples) and allows “flexible topologies” at that layer, so that you can do things like build the LaCie and Belkin Hubs, and that you can run a variety of different protocols from them, and just generally have things sitting on the line, but that the Physical Layer (Oranges) requires a single lane circuit, which is why the daisy chain. This makes sense to me as these would be extensions of a PCIe lane, and is why I’m doubtful that you’ll ever see a hub, other than hubs for other protocols. Again, my understanding may be incomplete or wrong, but after cursory examination while deciding wether I was going to buy a new Macbook Pro, that’s how I came to understand it.
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[Tim Wilson] “And for the record, since I was making sh^t up, I figured I might as well go for mb rather than MB…since as Jeremy points out, MB is perilously close to NOT making sh^t up.
[Note to Grant: Let me know if my “correction” – heh heh heh – needs more work. And again, sorry for letting the cat out of the bag.]
“Yes but MB, still would have been cool, and was convincing. Mb wouldn’t have got my goat at all. And, mb still isn’t anything.
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[Michael Gissing] “One day FCS3 will break in Lion or Mountain Lion and it won’t be fixed. This is the time old Apple way. It comes down to personal preferences and I have a lot to lose and zero to gain by installing FCPX at the moment.”
I just lost Motion on one of my Lion machines in a way I can’t yet explain. Hopefully it will reinstall when I have a chance to do so.
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[Tim Wilson] “The plan is the plan until the plan changes.”
And when it changes, it was always the plan.
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[Andrew Richards] “The implication is clear. OS X and iOS are separate UIs for separate use cases, and they will remain so. “
We also know that the Air is safe. What makes me really angry, though, is that it is also clear that they’ve abandoned the Toasterator. I wanted one in white with a nice Braun-like finish.
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[Tim Wilson] “I’ve been reading this thread with interest, but just read the subject line more carefully. DUDE! You did NOT say off-topic?!?! I’ve seen maybe 6 threads in the past year that I’d classify as off-topic, and this is definitely not one of them.
Thanks for the thought though. 🙂
“Tim, just for future reference, is it the discussion of the Thunderbolt adapter or the simple culinary comments that keeps this thread topical for this forum?
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[Craig Seeman] “Only tainted if you’re looking for objectivity. “
I think this is my single favorite quote of the year so far.
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[Alan Okey] “Just you wait and see, Apple is going to release a Super Duper Mac Mini Pro Workstation with infinite CPU and GPU power via Thunderbolt expansion. And everyone who buys one will get a free puppy.”
You know, Alan you say things like that, but I have to tell you the puppy was really nice, really sweet, and it tasted great.
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[Chris Kenny] “[Jason Porthouse] “Whilst we’re on the subject, does anyone do a Thunderbolt ‘hub’?”
The Thunderbolt specs say it supports such things, but nobody seems to be making one yet.
“I don’t believe thats the case. I could be wrong, but I believe the nature of Thunderbolt requires a single chain like SCSI.