Testing the Pieces

Before we get to the display and Thunderbolt specific testing I wanted to confirm that the individual controllers in the Thunderbolt Display were just as capable as those in the Mac it was connected to. For the most part, they are.

Following in Brian Klug's footsteps, I created two RAM disks - one on a MacBook Air and one on a MacBook Pro. I connected both systems to my local GigE network and copied giant files between them. I measured over 780Mbps going from the MacBook Air to the MacBook Pro, and 832Mbps in the other direction (images below). That's about as good as it's going to get.

Next I tested performance over FireWire 800 and USB 2.0. For FireWire 800 I used a Western Digital My Book Studio Edition II configured in RAID-1 and measured peak read speed from the device. For USB testing I turned to a Corsair Flash Voyager 3.0 (USB stick) and a SF-2281 SSD connected to a SATA-to-USB bridge. In both of the USB tests I measured write speed to the USB 2.0 devices. Apple appears to have chosen its FireWire controller well as performance was only off by 2MB/s compared to the FW800 port on the 15-inch MacBook Pro. USB 2.0 performance wasn't nearly as good however, I maxed out at 16.4MB/s and saw typical rates closer to 15MB/s:

Transfer Rate Comparison
  FireWire 800 USB 2.0 (stick) USB 2.0 (SSD)
Apple Thunderbolt Display 70.0 MB/s 14.1 MB/s 16.4 MB/s
Apple 15-inch MacBook Pro (2011) 72.0 MB/s 21.2 MB/s 32.2 MB/s

Both the audio controller and FaceTime HD cameras interface via the Thunderbolt Display's internal USB controller. It's likely that one of those devices is forcing the controller to negotiate at a lower speed and thus ultimately limit peak USB 2.0 performance through the display. Note the gap in performance is much smaller if you're looking at transfers to a USB stick vs. an SSD. I happen to have a lot of SSDs around so I tend to use them as glorified USB sticks, I suspect the majority of users won't notice much of a difference due to the lower overall performance of standard USB sticks.

FaceTime HD Camera

Although Photo Booth in Lion captures at 1080 x 720, using iSightcapture I was able to confirm that the sensor in the Thunderbolt Display appears to be able to capture 1280 x 720 natively. Quality is what we'd come to expect from the current generation of FaceTime HD cameras.

I tested the camera both in Photo Booth and in a FaceTime chat with our own Brian Klug. The experience worked fine in both cases.

FaceTime seems to have issues when one party is in a noisy environment but that doesn't appear to have anything to do with the Thunderbolt Display hardware as I duplicated the issue on a MacBook Air as well. If you're curious, the problem I'm talking about occurs when the party in a quiet environment is trying to talk to the person with a lot of background noise. The quiet party will hear audio just fine but the noisy party will get a lot of broken up audio from the other side. It seems like FaceTime is trying to do some active noise cancelation that ends up doing more harm than good. I confirmed it's a FaceTime software problem by calling Brian via Skype without any issues.

The Changing Role of Displays Thunderbolt Performance
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  • repoman27 - Monday, September 26, 2011 - link

    Well, the display itself is driven by DisplayPort. The ATD does require Thunderbolt though, otherwise they couldn't have included all the other stuff. Apple is releasing this as an accessory for new Macs that have Thunderbolt ports. It does not make anything obsolete. You can continue to use pretty much any display on the market with either an older Mac that only supports DisplayPort or a new Thunderbolt equipped Mac although you might need an adapter or three. Most display manufacturers are probably not going to go the Thunderbolt route, and will stick with HDMI for 1920x1080 panels, DisplayPort for the higher resolution jobs, and DVI ports until the cows come home.

    Apple may soon cease production of discrete DisplayPort sink devices, but that in no way means that they've turned their back on the standard. Thunderbolt ports are indeed backward compatible with DisplayPort devices, but DP ports have no way of being forward compatible with Thunderbolt devices.

    I find it odd that there are a lot of folks asking where all the Thunderbolt devices are, and then when one is released, everyone complains that they would need to buy a new Mac in order to use it. Thunderbolt devices are designed to be used with Thunderbolt enabled PC's, you're either in the market for them or you're not, end of story.
    Reply
  • eureka_swe - Monday, September 26, 2011 - link

    If you have say 2-3 FireWire 800 disk connected to the Display, do i need to Eject this on the Macbook Pro evry time i will disconnect the Display or is it just to pull out the Thunderbolt cable and the disk is still good ?

    its a big question for me that have 7 FW Disks :)
    Reply
  • Constructor - Monday, September 26, 2011 - link

    That you need to unmount volumes which are about to be disconnected doesn't change.

    The external FireWire controller is basically indistinguishable from one on the motherboard for the OS. And the file system is still the same.

    So unmounting any external FireWire, USB and (directly) Thunderbolt device is a must and will remain so until the file system is fundamentally altered in that regard.
    Reply
  • iSayuSay - Monday, September 26, 2011 - link

    Agreed on some Anand's points. Hooking a Macbook Pro/Air with Thunderbolt onto that display may looks cool, it might instantly look like a desktop. But the real performance is never going to be excellent, it only become acceptable - very good range.

    If I going to cash in such amount of money (consider basic 11" MBA for $900 + 27" Apple Thunderbolt display for another $1000, and for elegance purpose .. don't forget TrackPad/MagicMouse + Wireless keyboard for another $140) ..

    In total you already spend same amount with hi-end iMac 27" which performs much better, yeah sure .. it's not portable, but I don't carry around my MBA too much either :p

    So I say .. while looks nice and cool, I'm not ready to follow world trend to go mobile with today's performance
    Reply
  • dgingeri - Monday, September 26, 2011 - link

    I flat out refuse to buy any Apple products. I have 3 reasons behind this now. At first, it was because they did so much business with Foxconn, and the horrible living conditions of the Foxconn employees who built Apple products. Then I found out about their excessive patent applications on a great many things that have been common habits of electronics manufacturers for over a decade. Now, I add on the excessive legal activity and flat out cheating in court trying to ban competing products.

    Apple is quite simply an evil company. Do not buy their stuff. Do not support the attempt at becoming a dictatorship of the world under the guise of business.
    Reply
  • Mystermask - Sunday, October 09, 2011 - link

    You're a hypocrite if you accuse Apple for what happens in chinese factories.
    1. Name me one brand that does not go for cheap as possible production. And why? Just have a look at those endless discussions where people try to prove that they can build a PC that has the same specs like e. g. a MacBook Pro but is even cheaper. How do you believe this is possible?Aren't you happy when you can buy a PC for €300 when all other cost 500€? Who do you believe is paying that bill? The "race to the bottom" has a long history that started in the PC industry when almost all HW vendors decided to go with DOS / Windows and vendors could only distinguish themselves in the market by being cheaper than others. And consumers gladly bought the cheapest - unable to distinguish value and price - effectively cutting into their own flesh because this has cost all production jobs in the PC industry in western countries.
    2. Have a look at yourself. Do you wear Nike, Addidas, Reebook, Lacost, you-name-it? Do you use Dell, Acer, HP, HTC, Samsung, .. How and where are they produced?
    ..
    All of a sudden, reality looks not as easy and religios blind Apple bashing is certainly neither a solution nor would that change anything for Foxconn or countless other factory workers in China, Vietnam or wherever people have to offer their work for cheap to survive because of western ignorance and greed.
    Reply
  • The_Countess - Monday, September 26, 2011 - link

    i cant help but notice that you could do all this with just 2 cables for far less money and without the expensive proprietary technology.
    1 display cable + 1 usb3.0 cable connected to a USB hub.

    it'll even be fully backward compatible with practically every laptop still in operation on the planet!

    you could even run the display over usb3.0 although I'm not sure how much bandwidth would remain after that.
    Reply
  • repoman27 - Monday, September 26, 2011 - link

    You can get more than 800 MB/s of throughput from a RAID connected to a USB 3.0 hub?... While getting over 780 Mbps over a USB 2.0 Gigabit Ethernet adapter?... (There are no USB 3.0 ethernet adapters in the wild yet.) While recording 720p video from a camera connected to the hub?... While playing back audio from a USB audio interface?... And how are you going to connect a FireWire device to your USB 3.0 hub? There's no adapters for that, and besides, you're out of ports on your hub because the only USB 3.0 hubs on the market have just 4 downstream ports. Looks like you'll need to get another hub and cable to connect a keyboard and mouse or USB disk.

    And yes, you could connect your version to any laptop and enjoy all of those devices sharing less than 40 MB/s of bandwidth, or connect it to a USB 3.0 enabled machine and get less than 400 MB/s. Thunderbolt gives you 2500 MB/s. A 2560x1440 display such as this requires 5.8 Gbps of bandwidth, USB 3.0 can't even hit 3.2 Gbps of real world throughput yet.
    Reply
  • Constructor - Monday, September 26, 2011 - link

    USB ist not remotely capable to drive a display at the same performance level as the built-in GPU in the computer can. Those USB graphics adapters are orders of magnitude slower than that.

    And both 10Gb/s input + 10Gb/s output at the same time as a high-res display (or even two of those with a small output performance hit) are completely out of range for even USB3.

    Add to that the horrible latency problems you've got with USB, which are completely absent with Thunderbolt. (Which is one reason why you couldn't even have a full-performance FireWire port through USB3 since proper FireWire has very low latencies as well, which USB simply can't emulate.)

    USB is a very complicated and not too fast peripheral interface.

    Thunderbolt is effectively a part of the motherboard channeled through a thin cable to pluggable external motherboard expansions (the "motherboard" in the Thunderbolt display is effectively made a part of the computer's motherboard once you plug it in to the Mac).

    Completely different deal.
    Reply
  • AnnonymousCoward - Tuesday, September 27, 2011 - link

    You're comparing USB to a GPU? ok...

    "orders of magnitude"? USB is 5Gbps; apparently the alternative is 500Gbps!! Sorry, it's not even 50Gbps, or even half of that.

    "horrible latency problems you've got with USB" - I have no perceivable latency on my USB mouse, and I'm sensitive to it.

    "USB is a...not too fast peripheral interface." - 5Gbps isn't fast? No external connection aside from raw video can utilize that!

    Face it, you don't know what you're talking about.
    Reply

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