Final Words

There are really two things that need concluding in this article. We'll start with the Promise Pegasus R6. Without a doubt this is the highest performing external enclosure you can get for your 2011 MacBook Pro or iMac. Even using lowly mechanical hard drives you can get absolutely amazing sequential performance out of the R6. In its beefiest configuration you get 10TB of storage that you can readily access at over 600MB/s. For a MacBook Pro or iMac user that does a lot of HD video work, this amount of high speed storage is just unheard of. The big tower guys have always been able to piece together beefy RAID arrays, but now you're able to get that sort of an experience in a more compact computing device.

I'd love to see Promise offer a version of the Pegasus with SSDs instead of mechanical drives. If Promise didn't want to retool the Pegasus' design it could come in the same chassis, but it'd be really nice to see an even smaller form factor chassis designed exclusively around the 2.5" form factor. I've already shown what four high speed SSDs can do in the R6's chassis. You obviously don't get the capacity but I suspect there's a class of users out there that needs more than what a MacBook Pro can offer with its internal drive bays, but doesn't quite need 10TB of storage.

The Promise Utility that comes with the Pegasus is nice but I found it slightly temperamental at times. I almost feel like we're another couple of software/firmware revisions away from a more polished solution, although admittedly I didn't encounter any issues when I was just using the device as configured.

The biggest drawback to the Pegasus is its price. At $1999 fully loaded, or $999 for an entry level 4TB R4 it's just a very difficult device to justify. I suspect if your work depends on it then you'll have no problems spending the money, but it is a very niche product as a result. I would like to see Promise or someone else offer a barebones Thunderbolt chassis for those users who need this sort of performance but at a better price point. I can understand the price premium for Thunderbolt, but at these prices the technology is simply out of the reach of too many who could honestly use it.

Which brings me to the next topic of discussion: Thunderbolt. The interface is fast, there's no doubt about that. With the right drive configuration I had no problems pushing 8Gbps over the PCIe channel while sending another ~7Gbps over the DisplayPort channel to a 27-inch monitor. It's clear that Thunderbolt has what it takes to really enable more users to migrate from big desktops to high powered quad-core notebooks. The interface effectively solves the high speed local storage issue.

I'd love to see Apple get really aggressive here and offer a Cinema Display with two Thunderbolt ports, more USB ports, Ethernet and audio out. Then MacBook Pro users would only have to run a single Thunderbolt cable + power to their notebooks when they're docked at a desk. I'd also like to see full-speed performance when used in Target Disk Mode. Thunderbolt could become the new defacto way to quickly migrate data between Macs.

I am concerned that we may run into bandwidth limitations in the not too distant future. If we can already push 5 - 8Gbps of data on a single channel, what happens when you run Gigabit Ethernet and USB over Thunderbolt as well. For high end users, I see a definite need for faster signaling or multiple Thunderbolt ports.

I also have concerns about cable costs and widespread adoption. For Thunderbolt to really take off we need to see tons of products that support it. Intel's Thunderbolt controller IC can't be cheap, so I am curious to find out if more companies will give Thunderbolt a try. I believe cable costs can be prohibitive, but today device costs are the bigger concern.

Intel already announced that we'd see Thunderbolt support in Ivy Bridge designs next year so it may be at least one more year before we see just how much market potential Thunderbolt has. While I'm happy that Apple is championing the standard, Thunderbolt really needs widespread industry support to make an impact.

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  • Conner_36 - Friday, July 8, 2011 - link

    Or even in the office, to able to take your entire project and move between the rooms carrying ALL of the data? That's unheard of!

    From what I understand with HD movie editing I/O is the bottleneck.

    All we need now is an SVN hardware device with thunderbolt to sync across multiple thunderbolt RAIDs. Once thats out you could have a production studio with some real mobile capabilities.
  • Exodite - Friday, July 8, 2011 - link

    I wager pretty much any usage scenario can come up with a high-performance 12TB storage solution for significantly less than 2000 USD.

    You're right though, it's definitely not the solution for me.

    Or anyone I know, or am likely to ever know. *shrug*
  • Zandros - Friday, July 8, 2011 - link

    What happens if you try the Macbook Pro -> Pegasus -> iMac in Target Display Mode -> Cinema Display connection chain?
  • Focher - Saturday, July 9, 2011 - link

    Pretty sure the DP monitor has to be the last device in the chain. Maybe that is just a current limitation because there are no Thunderbolt displays.
  • Zandros - Monday, July 11, 2011 - link

    AFAICT, the iMac is a Thunderbolt display, since it does not support Target Display Mode from Display Port sources with Display Port cables.
  • tipoo - Friday, July 8, 2011 - link

    Is there a way to make it shut off the drives after idling for a while?
  • piroroadkill - Friday, July 8, 2011 - link

    But when you saw the file creation maxed out at 9TB, on 10TB array..

    Since.. uh, Snow Leopard, Apple changed file and drive sizes to display decimal bytes as used by the manufacturers, which is the same as the 10TB array.
    However every other thing ever reports in binary bytes, such as windows describing "gigabytes" even though it means gibibytes in reality.

    Ugh, anyway, what I'm trying to get at is that maybe you did infact fill the array. That said, the thing shouldn't have fucked up..
  • CharonPDX - Friday, July 8, 2011 - link

    If I had way too much money, my usage model for Target Display Mode would be to use the iMac as a Virtual Machine host/server, connected to either a second iMac or a MacBook Pro as a dual-screen workstation.

    With the minimum 27" iMac, you're basically buying a 27" Cinema Display plus a $700 Mac mini-on-steroids. If you want a second Apple display for your iMac or MacBook Pro, and want a Mac Mini to use as a server, that is an excellent value to instead just get a second iMac. (That value may drop depending on the next Mac Mini update, of course.)
  • etamin - Friday, July 8, 2011 - link

    in the block diagram on the first page, why is the Thunderbolt Controller connected to the PCH thru PCIe rather than to the processor? I thought PCIe connections came off the processor/NB?
  • repoman27 - Sunday, July 10, 2011 - link

    The lanes that come off the processor/NB are usually used for dGPU. On the new MacBook Pros, Apple borrowed four of them for the Thunderbolt controller. Apparently on the new iMacs, however, they decided to give all 16 lanes from the CPU to the graphics card and pulled four from the PCH instead.

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