The Apple Thunderbolt Display Review
by Anand Lal Shimpi on September 23, 2011 2:56 AM EST- Posted in
- Displays
- Mac
- Apple
- Thunderbolt
- Thunderbolt Display
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.
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.
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name99 - Friday, September 23, 2011 - link
"The iMac and displays like this compell people to discard those expensive displays far ahead of their time and likely buy another display of the same size and resolution."And discard means WHAT? I can go to eBay and see the prices for second hand macs. What's stopping you from selling your iMac, or giving it to a friend/family member/school?
You claim there area significant number of still-working flat-screen iMacs in closets or the trash. I call bullshit.
dave1_nyc - Friday, September 23, 2011 - link
Anand, I liked the review, and I think this sounds like interesting technology, but honestly, but you sound as though you've never used a docking station. Yes, you're right, they are all proprietary, but the good ones from Dell and Toshiba (and I'm sure others) are terrifically useful if one needs one.I don't, but there are people in my org for whom their laptops are their main machines and they take them back and forth between the office and home every day. All the modern docking stations provide pretty much any connectivity you could want, and they allow you to use any monitor you want, and switch out monitors.
Further, while connecting two cables (a la the review) isn't hard, with the laptops and docking stations we have you walk up and set the laptop down onto the station connectors. At which time the laptop (if thus setup) turns on, adjusts for the external display (or two), and that's that. If you have automatic login, you never have to open the laptop.
Expensive? We pay $150 for them, and with that comes the freedom to upgrade either the docking station (such as when the USB 3 ones come out early next year) or the monitor independently of each other.
Of course, the real docking stations (as opposed to those USB 2 things) are only found in 'business class' machines, but those machine can now be configured with discrete graphics if one wants.
I'm not trying to sell docking stations, but you're usually not quite so inaccurately dismissive.
jecs - Friday, September 23, 2011 - link
I agree with you. I think Apple or someone else should produce a docking station for Mac Books. I remember when I used those with an IBM laptop some years ago.If you want to use "an all Apple technology" the thunderbolt display is fine. But if you want a MBP and have a different need you will find yourself limited in options. But those parts need to be competitive in price and quality.
Constructor - Friday, September 23, 2011 - link
Why are you limited? Simply use a different Thunderbolt docking solution instead of the ready-made Thunderbolt Display.With Thunderbolt you can even customize your own special solution in a way you never could before, by daisy-chaining multiple Thunderbolt devices according to your own specific needs.
And the kicker is that you can carry it all over to a new machine, even when switching manufacturers and even platforms!
None of the pre-existing docking solutions ever came close to that.
Trefugl - Saturday, September 24, 2011 - link
But where are all these external devices that I can so easily purchase and make my own docking solution? Last I checked (admittedly a few weeks ago), there was a very limited selection on adapter types on the market.I do agree that this is a great solution (and one that actually makes me excited about thunderbolt), the problem is that no one has made an external hub like what's in the display yet... they might now that PCs are getting the same connector next year, but it just blows my mind that the first place you see this tech is stuffed inside a monitor (one that only can work at all with new '11 Macbooks...)
Constructor - Saturday, September 24, 2011 - link
Well, it works with all current Macs (the Mac Pro is the only one that hasn't been upgraded to Thunderbolt yet).And I would not be surprised if the availability of Intel Thunderbolt controllers was one of the reasons why third party devices are being delayed – at the number of Macs Apple is producing, it is quite possible they're buying every chip Intel manages to get out the door. But Intel has lots of experience with mass production of high-grade chips, so I have no doubt availability will catch up soon if it hasn't already.
Belkin is apparently designing effectively a Thunderbolt Display without the display:
http://gizmodo.com/5839952/belkins-thunderbolt-exp...">Belkin's Thunderbolt Express Dock Finally Gives You a Reason to Remember You Have Thunderbolt
And there's more in the pipeline from various manufacturers. Unsurprisingly, professional-grade interfaces which actually need the speed and low latency are among the first.
Constructor - Saturday, September 24, 2011 - link
The link has been crippled, apparently. This should work:http://gizmodo.com/5839952/belkins-thunderbolt-exp...
AbRASiON - Friday, September 23, 2011 - link
Defective by design.stepa - Friday, September 23, 2011 - link
Simple question (requires a simple answer)So does it mean that there is no way to connect this display to a windows pc as a main display?i know that with previous models you could use an adapter or newer gfx cards already have a display port.so this a no go for pc users?
KPOM - Friday, September 23, 2011 - link
Not until PCs with Thunderbolt ports start coming out next year. I suspect a lot of the Ultrabooks will do so since Thunderbolt support will be built into some of the Ivy Bridge chipsets.