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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  • A5 - Friday, September 23, 2011 - link

    No shit. Every single review, everywhere, where the hardware is provided by the manufacturer is advertising of some form. This is why you rarely see truly negative reviews of anything. Reply
  • ltcommanderdata - Friday, September 23, 2011 - link

    And what monitors are you looking at to get those prices?

    http://store.apple.com/us/product/MC914?mco=MjQ1Mz...

    The Thunderbolt Display is $999 not $1200.

    Dell's most comparable device is the U2711 which is IPS and is $1099 regular price, although it's currently on sale for $719.

    http://accessories.dell.com/sna/products/Monitors_...

    I don't know how frequently Dell does sales, but at regular price the Thunderbolt Display is in fact cheaper than Dell's while including more dock features like ethernet, firewire, speakers, etc.
    Reply
  • Stas - Friday, September 23, 2011 - link

    Do a google search on the model and you will find at least 5 online sellers that have the Dell monitor for <$850 Reply
  • Constructor - Friday, September 23, 2011 - link

    Sure. The Dell doesn't have an LED backlight, however, so apparently they're selling off the old stock with CCFL backlights before moving on to LED as well.

    It's tougher to get a larger colour space with a (white) LED backlight, but on the other hand it's mercury-free, uses significantly less power and lives longer than CCFL.
    Reply
  • doubledeej - Sunday, September 25, 2011 - link

    CCFL backlit monitors still have a better image. That's why you find them on the high-end monitors from other manufacturers. Apple is sacrificing quality by moving to LED. Look at the charts in the article. The Thunderbolt and Cinema Display monitors both fall in the bottom third of nearly all of them. They aren't that great. LED gives better power usage, but it comes at a price in terms of image quality. Reply
  • Constructor - Sunday, September 25, 2011 - link

    Better power efficiency, better longevity, zero mercury.

    Quite significant advantages.

    And in most metrics the TBD is actually pretty decent, particularly for its resolution and price.

    CCFL makes it cheaper to get a larger colour space than with RGB LEDs again at the very top.

    But for that it's far dirtier in all three dimensions (wastes power, turns the display into e-waste a lot sooner and releases mercury if not dismantled very, very carefully – and even then the mercury remains hazardous waste).

    Very few people actually have a use for an expanded colour space. Still few people actually experience limitations with brightness uniformity (my iMac 27" is fully sufficient for all my uses, with no problem noticeable). And all people benefit from the advantages.

    It would have been silly for Apple to make a display that's specialized to only very few people's needs and saddling everyone with lots of disadvantages. Eizo can do that. They've got many models and they are largely specializing on these kinds of uses (and even they are on their way towards LED backlights).
    Reply
  • jecs - Friday, September 23, 2011 - link

    He went to the Apple store and confused the starting iMac to the Thunderbolt display. Some are so eager trying to look calm and cool but forget to check the facts.

    And you started saying "Nice but..."
    Nice to what? if you did not check the real price you are objecting
    Are you going to say now that you like the Apple display?
    Reply
  • TypeS - Friday, September 23, 2011 - link

    Better check the price again there bud, it's $990.00USD

    http://store.apple.com/us/product/MC914LL/A?fnode=...

    The Macbook Air also starts at $990.00USD as well:

    http://store.apple.com/us/browse/home/shop_mac/fam...

    That's a grand total of $1980 before taxes

    The 13" Pros starts at $1199 as well.

    Dell lists it's U2711 at $1099 retail, with a current sale price of $949.

    If we take your assumption that ASUS/Samsung have similar spec'd and functional alternatives or $900, the total savings is $150.That is a far cry from half.

    Anti-apple critics are just as bad as the brainwashed Apple fanboys when they start pulling facts out of thin air.
    Reply
  • cactusdog - Saturday, September 24, 2011 - link

    The prices I quoted are from the Apple website in my country and they are accurate. Apple charge us a lot more than they do in the US.

    You're choosing the cheapest/smallest macbook that nobody wants and saying they are cheap. They are not. You can get a similar speced notebook for much less from Asus.
    Reply
  • mcnabney - Friday, September 23, 2011 - link

    Didn't you read the review? This display has poor color accuracy so you really can't compare it to displays that have it. Anand indicated that people accustom to laptop displays wouldn't notice it, but I guarantee that people who have historically bought and needed high quality displays WILL notice it. So you can't really compare Apple's new display to competitors that make displays for the publishing/imaging business. Reply

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