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Sharing a thunderbolt raid drive between two new Mac Pros
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Silence speaks volumes…
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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Hi Jose –
This is an old thread. Before I answer, I don’t get it. If you own a thunderbolt RAID and two Thunderbolt Mac computers, why not just test this yourself to see what happens. All you do it plug in the two thunderbolt cables to the RAID’s thunderbolt looping ports, and try it. You will find the answer in 2 seconds.OK – the answer is NO – it still does not work. Thunderbolt networking, with reliable speeds that you can edit with does not work. Once again, at NAB 2015, I spent a lot of time with the Intel guys in the UPSTAIRS south hall discussing this. It’s still being worked on, but it does not work. Intel showed a demo of 6 computers daisy chained to each other with Thunderbolt. You lose 10% performance with each daisy chain, and that does not account for the sporadic poor speeds that you get with a direct thunderbolt connection.
However, if you simply hookup some thunderbolt to 10G Ethernet adpators from Sonnet, ATTO, or Promise, you can do exactly what you want using a Mac Mini as the server. If you want a pure thunderbolt product, you can buy the new Accusys that allows you to connect up to three computers (no expansion) with thunderbolt – $10,000 for 64 TB, and you need a mac mini server for the XSAN metadata and Tiger share or XSAN running on your workstations.
SO NO – there is no cheapo solution where you just plug in two computers with simple thunderbolt cables. Not as of May 2nd, 2015.
Bob Zelin
Bob Zelin
Rescue 1, Inc.
bobzelin@icloud.com -
Hi Bob,
The reason I didn’t just test this out myself is because I’m not the one doing the setup, rather I’m trying to find the best solution for my IT guys that will be implementing a shared raid. I’m a bit wary of this but they believe it’s a viable option so I’m just doing my research. I do really appreciate you taking the time to give your input on this matter.
In your testing, was it done with Thunderbolt 2? I’m wondering if that would make a difference. Thanks for your other suggestions as well. I think that’ll be helpful in trying to figure out a budget friendly solution.
Best,
_jose
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Since there’s no hardware, and thus no hardware offloading, it’s all being done in the kernel. So Thunderbolt 1 vs 2 isn’t the issue. Clearly the hardware has the ability to do the work when using 10GigE physical cards.
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[jose fuentes] “I’m trying to find the best solution for my IT guys… …I’m a bit wary of this but they believe it’s a viable option so I’m just doing my research. “
IT guys invariably think they know everything if it’s in any way related to computers and networking – unfortunately most know nothing about the requirements of video, which differ greatly from the day to day data requirements of most businesses.
In this case, your IT guys “believe it’s a viable option,” because sharing video over T-bolt between two computers seems logical. Unfortunately, what sounds logical does’t always translate into reality, and this is one of this cases.
The issue is, there is no TCIP protocol built into Thunderbolt, so your IT guys will discover packet loss issues will prevent them from achieving seamless playback of video files across the network.
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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[Chris Murphy] “Since there’s no hardware, and thus no hardware offloading, it’s all being done in the kernel. So Thunderbolt 1 vs 2 isn’t the issue. Clearly the hardware has the ability to do the work when using 10GigE physical cards.”
Chris,
There is simply no TCIP protocol built into Thunderbolt, so packet loss inevitably causes video playback issues across the network.
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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Why would there be packet loss with a properly built network? And how does checksum offloading mitigate packet loss? My answers are, it wouldn’t, and it doesn’t. The issue is strictly performance because at 10GigE speeds (possibly 20Gbps since it’s full duplex) it’s a massive amount of checksumming occurring. This siphons CPU cycles away from all video editing tasks when done in software than hardware since it’s the kernel that has to do that checksumming work, instead of the NIC.
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You don’t seem to have read what I wrote, or seem to be missing something. So, let me repeat, Thunderbolt has no built-in TCIP protocol, without it you get packet loss, and thus inconsistent video playback over networks.
***Just to be sure you understand what we’re talking about here Chris, we are NOT discussing 10GbE connectivity via Thunderbolt expansion chassis – the original poster wants to share video from a single T-bolt RAID over T-bolt, with no server, no expansion chassis, and thus no 10GbE PCIe NIC cards.
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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I said from the outset that without hardware (a NIC) there’s no hardware offloading. The work the NIC hardware would otherwise do is being done in the kernel. If you disagree with some aspect of that, address that separately.
Twice you’ve referred to TCIP protocol, so now I’ll have to assume it’s not a typo and I’ll ask you to define that acronym because I don’t understand it. If you mean TCP/IP (they are two different things, they’re not the same protocol) then what you’ve written doesn’t make much sense. Airport cards typically don’t offload TCP/IP checksumming, this gets done in software, and yet packet loss results in retries (when using TCP, not UDP of course), so this wouldn’t make any difference with TCP/IP over Thunderbolt (minus NIC).
Also I advise not passively calling someone a moron by stating the only two possible reasons for miscommunication is they’re not reading what you’ve written or that they’re the one missing something. It has a tendency to degrade the conversation.
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[Chris Murphy] “Twice you’ve referred to TCIP protocol, so now I’ll have to assume it’s not a typo and I’ll ask you to define that acronym because I don’t understand it. If you mean TCP/IP”
Actually, I looked back over several posts and I noticed the same typo three times. Clearly should have been TCP/IP – that’s spell check at work…
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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