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
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  • MobiusStrip - Friday, September 23, 2011 - link

    I wish someone would have the balls to step up and end this moronic glossy-screen fad.

    Glossy sucks in all lighting conditions. It doesn't matter where the illumination is coming from in the room, or even if there IS any. At the very least, the light from the monitor is going to illuminate YOU, putting your reflection over those supposedly "deep blacks" and "rich colors." Glossy screens work for one customer: the ninja in the closet.

    Going from a glossy screen to matte is like cleaning a filthy windshield: You wonder how you put up with it until that moment.
    Reply
  • retrospooty - Friday, September 23, 2011 - link

    "Glossy screens work for one customer: the ninja in the closet."

    At the risk of outing my secret identity, we closet Ninja's reject your claim!
    Reply
  • Colorblinded - Friday, September 23, 2011 - link

    You and me both. I can tolerate it on my phone but my desktop or laptop are matte only. Reply
  • HMTK - Friday, September 23, 2011 - link

    ++

    That and widescreen resolutions. Gimme a 4:3 high res matte screen anyday!
    Reply
  • Constructor - Friday, September 23, 2011 - link

    Well, 16:9 with a 2560-pixel display still gives me 1440 pixels vertically, surpassed only by the 1600 in a 16:10 30" panel which costs double the price and significantly more than in any of the smaller resolutions.

    So I can live quite comfortably with my iMac 27" (same panel as in the TBD). "Suffering" on a very high level, so to speak. 8-)
    Reply
  • doubledeej - Sunday, September 25, 2011 - link

    I've always felt like integrated monitors are a waste. The trouble with iMacs (and all All-in-Ones) is that you have to buy your monitor over and over again each time you buy a computer. So ~$800 of your computer's price went toward getting that 27" monitor, and when your computer dies, so does your display, and that money is lost.

    I've been using the same four high-end LCDs for my last three computers. I'll gladly spend $500/yr to ensure I have the latest and greatest computer without having to invest an additional dime in new displays.
    Reply
  • Constructor - Sunday, September 25, 2011 - link

    Macs generally life for many years. Actually, none of mine has ever "died". Even my first one from the early 1990s still works as on the first day.

    Plus, recent iMacs can serve as external monitors for other computers.

    Maybe you're just switching your computers a little frantically compared to most other people. My Macs have so far been in productive use for 5-6 years each and are just mostly collecting dust since retirement because I chose not to sell them to someone who could get good use out of them even after that.

    This is my first iMac. I'll see whether I'll keep it around as a monitor for its successor or if I'll just sell it off when the time comes. It's a pretty good concept, however, and it works very well in practice.
    Reply
  • jecs - Friday, September 23, 2011 - link

    I am stepping up (balls?) but to say you think you know what you are talking about but you are not.

    The thunderbolt display is a high end consumer display not a professional level display.
    Even the Dell 2711 is an entry professional monitor. Dell Is better suited for color correction and wide color gamut space but not the real broadcast deal.

    Where, where in a broadcast professional production environment would you even consider an Apple display? Maybe on press production for everyday news or on production studios for independent production on constrained budgets who don't depend on critical wide color gamut.

    80% of consumers and most professional not working on critical color correction don't care for mate screens. Glossy screens are better for watching a movie or content and in a controlled environment this is acceptable.
    Reply
  • name99 - Friday, September 23, 2011 - link

    "The thunderbolt display is a high end consumer display not a professional level display."
    "Where, where in a broadcast professional production environment would you even consider an Apple display?"

    If only there were professions OTHER than "broadcast professional"...
    But sadly we live in a world where every professional is a broadcast professional, and clearly Apple has screwed up in making a device that appeals to print workers, or programmers, or musicians. None of them, after all, are professionals...
    Reply
  • jecs - Saturday, September 24, 2011 - link

    80% of people buying from Apple opted for glossy screens, this is a fact. The 20% that opted for mate screens still have the "optional antiglare display" in 15-17 Mac book Pros.

    Now, photographers, programers, musicians or other professional working with a "Mac Pro" have great options from other very well recognized vendors like LaCie, NEC, EIZO, HP, Dell and others.

    Apple as well as Dell have always been a cheap competitive alternative for higher end displays but never the best dedicated option for professionals who depend on the most accurate screen.

    The only ones abandoned are the casual, or entry level professionals that got use to working with Apple displays and some high end aficionados. That is true, but those could buy today a LaCie Monitor for around $950.

    I don't know, Apple could launch a mate display line whenever they see the opportunity, but they appear not seeing a good one in the present. Maybe they don't consider the number of professionals buying from Apple enough to produce more mate displays.

    Cheer up!
    Reply

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