Thunderbolt Performance

The Eagle Ridge Thunderbolt controller is home to two Thunderbolt channels, each one is good for up to 10Gbps in either direction (up or downstream). That works out to be 20Gbps of bandwidth per channel or 40Gbps aggregate between the two. You can only send two channels worth of data down a single Thunderbolt cable, so there's no point to having more than two from a performance standpoint unless you have more than one port on your system.

If DisplayPort and PCIe traffic are indeed carried on separate channels, then the Thunderbolt Display by itself is eating up around 70% of the bandwidth of a single channel on its own (2560 x 1440 x 32bpp x 60Hz with 8b/10b encoding > 6.75Gbps). That leaves 10Gbps in each direction for PCIe traffic. If we look at our benchmarks from the previous section we see that we can hit just under 2Gbps with all of the auxiliary interfaces (GigE, FW800, USB2) running. Given our previous investigation with the Promise Pegasus we know that 8Gbps is feasible there as well. It's possible, that with everything running at once, we could actually run into bottlenecks with Thunderbolt.

To find out I ran a few tests. First I needed a baseline so I threw four SF-2281 SSDs into the Pegasus R6 chassis and configured them in a RAID-0 array. I ran a 2MB sequential read test (QD=16) and measured 909MB/s from the array. This value was obtained without the Thunderbolt Display connected, only the Pegasus R6.

Next I connected the Thunderbolt Display directly to my test MacBook Pro, and then connected the Pegasus to it. I repeated the test, this time getting 900MB/s. Thankfully the presence of the Thunderbolt Display doesn't seem to impact the max data rate I can get from the Pegasus.

For my third test I added a Gigabit Ethernet transfer from a file server to a local SSD using the GigE port on the display. During this test I was also playing back music using the Thunderbolt Display's internal audio codec and speakers. I re-ran the Pegasus test and got 855MB/s.

For my final test I re-ran the third test but added a FireWire 800 to USB 2.0 SSD transfer, both connected to the Thunderbolt Display. I also fired up the FaceTime HD camera on the display using Photo Booth and left it on during the test. The final performance score from the Pegasus was 817MB/s.

Apple Thunderbolt Display Performance

With everything running Thunderbolt performance took a 10% hit. Note that the standard Pegasus configuration isn't able to hit these data rates to begin with, so unless you've pulled out the 12TB of storage and stuck in your own SSDs you won't see any performance drop.

What this does tell me however is the ultra high end users that are looking to daisy chain multiple Thunderbolt storage boxes together may not want to do so. I only have a single Pegasus R6 on hand, but I'm guessing there will be significant performance drop off after the first box. Not that I'm complaining about being able to push nearly 1GB/s over a $49 cable from a notebook, I'm just trying to give a heads up to those who may have aspirations of even higher performance.

Testing the Pieces Display Testing - Color Quality & Uniformity
POST A COMMENT

275 Comments

View All Comments

  • sportherz - Tuesday, September 27, 2011 - link

    if I understand correctly, the test was done with a MBP. I was excited about the new TB display together with a new MBA so I ordered both. Since my TB display arrived last week I am not so excited anymore. The display causes the MBA to heat up such that the fans of the MBA are constantly running at 6000rpm making a loud and annoying noise. If I use the MBA on my old 24 inch cinema display I don't have that problem. Could you please test the performance using a MBA and see if this is a problem about the particular monitor MBA I have, or if it is general

    Thanks
    Reply
  • MacTheSpoon - Tuesday, September 27, 2011 - link

    Is it really necessary to spend all that money just for a laptop dock? I guess if you're already going to buy an external display and it must be an Apple display it makes sense. But what about a cheaper solution like this third-party dock, the Henge Dock? I think it's $70. I'd be curious to see Anand test that out. Maybe there are other third-party docks out there he could test, too. Reply
  • Constructor - Tuesday, September 27, 2011 - link

    The Henge Docks only re-route existing ports, so you gain nothing, except being able to (dis)connect those multiple ports in one single motion, but you lose the use of the internal display, keyboard and touchpad of the MacBook Pro.

    For the MacBook Air that's not even an option since there is just one USB port to re-route anyway on the side of the MagSafe connector.

    With the Thunderbolt Display you primarily pay for a large 2560*1440 display with LED backlight in a high-grade casing and with relatively good environmental compatibility. You don't get any comparable display alone for much less.

    All the additional ports and the easy connection through MagSafe and Thunderbolt in a single thin cable are effectively a bonus, if a very welcome one, particularly for the MacBook Air.

    And you can still use the built-in display, keyboard and touch pad of the MacBook in additon to the other ports of the MacBook directly.

    Not a bad deal, all in all.
    Reply
  • sheh - Tuesday, September 27, 2011 - link

    that "DC brushless" thing.

    About the audio problem, wouldn't it be the fault of both the display and the TB device? I wouldn't expect a faulty USB device to cause problems to other things connected to the computer (at least if the computer didn't get stuck), why not expect the same with TB?
    Reply
  • Wskcondor - Monday, October 10, 2011 - link

    I read this review and also the 2011 iMac review. I have a couple of questions someone with the hardware in front of them or with more knowledge may be able to answer...

    My idea is to travel with the 2011 Macbook Air, with the 1.8G i7 upgrade and 256G SSD.

    -I like the Thunderbolt display idea of a dock, because when I am "at home" I do a lot on the computer at the desk and I store a lot externally from the Air (movies, music, photos) and also still use an optical drive regularly. In effect, with a T-Bolt display, all of these things would be hanging off the display.

    Then I thought: why couldn't I buy a 2011 iMac and use it as a "display/dock station" when at home?

    1) Could I boot the 11" Air into TBolt target drive mode and then BOOT the iMac from the Air's drive, so all the "local changes" would be on the drive I take away on travel with me? The processor would be an i7 also in the iMac. BUT the configuration would be different, of course.
    -will this jack up settings in the Air's hard drive when I disconnect and reboot the Air from it's internal processor?
    -will this be too slow a configuration because the TBolt target drive mode has such slow throughput that the iMac will crawl along?
    -Can I even boot an iMac off the Air's TBolt target SSD drive?

    2) Can the iMac become a "Thunderbolt monitor" with drives, ports, etc if I boot the iMac into TBolt target mode? Or would it just be a blue screen with drives and ports, extending my Air's ports, but not acting as an external monitor?

    Questions.

    thanks to anyone who knows.

    Wskcondor
    Reply
  • mashimaroo - Monday, October 31, 2011 - link

    i love this review. i have been thinking about setting up this EXACT same thing. i currently have a dell laptop that i plug in a billion cords into each time i take it somewhere. Its frustrating to have to plug in 7-8 things and have so many cords.. simplifying is great. My aaxa p4 pico projector is built with the same concept with an onboard media player that can play all my files directly off its memory, Reply
  • freedownloadaz - Wednesday, November 9, 2011 - link

    you review is very useful and can I buy it on eBay, I often download and buy here: http://freedownloadaz.com Reply
  • EmmanuelDécarie - Thursday, January 19, 2012 - link


    FYI, I just bought a Thunderbolt Display yesterday (2012-01-19) and I have plugged a Creative Xmod USB sound card (http://us.store.creative.com/Creative-Xmod/M/B000I... in the monitor and it works perfectly. I can use my own speakers that are much better than what comes with the monitor. So from my point of view, I don't miss the audio port on the monitor.

    I guess the Griffin iMic (http://store.griffintechnology.com/imic) could also works as a USB sound card to output sound from the monitor to your own speakers. But this solution is a bummer since this sound card don't add anything to the quality of the sound as do the Creative Xmod. So, you're right to say that's an oversight from Apple not to have an audio port. And Apple could have added more USB ports too.

    Thanks for your great review that helped me to take the jump to this magnificent display.
    Reply
  • EmmanuelDécarie - Thursday, January 19, 2012 - link

    Your CMS mangled the URLs.

    Creative Xmod

    http://us.store.creative.com/Creative-Xmod/M/B000I...

    Griffin iMic

    http://store.griffintechnology.com/imic
    Reply
  • anthony11 - Friday, July 20, 2012 - link


    "today I have no less than seven cables"
    Reply

Log in

Don't have an account? Sign up now