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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GotThumbs - Friday, September 23, 2011 - link
Anand,Love the Video Review format. While I think the product is nice and provides access to new tech, I have issues with Apples proprietary format. During a time where many users are going with multi-monitor configurations (I use dual Dell 30" monitors at work). I think combining functionality in a monitor limits/restricts users down the road. I would have liked to see purhaps an external Thunderbolt expansion system that would mount on the back of ANY monitor (via vesa). This would allow users the flexibility to upgrade/swap monitors as needed/desired. In today's technological world, we should be embracing expansion flexibility instead of restriction. It just seems to me that Apple continues to breed products that are proprietary in nature. Reminds me of the old Packard Bell systems where much of the internal hardware was proprietary. Thanks, but no thanks.
Keep up the good work and best wishes.
PS. I've been an AnandTech reader since your HS days.
Constructor - Friday, September 23, 2011 - link
The TBD just adds to the capabilities of your machine, it doesn't take away from it. You can daisy-chain other Thunderbolt add-ons as you want.Nobody prevents anyone from making a multi-port extension box without a display built in. Apple just chose to do it this way. You can even combine both if you want (and once the other announced extension boxes becomne available).
Beyond Thunderbolt being owned by Intel, there's nothing proprietary about the TBD. It's apparently just a relatively straightforward implementation of some of TB's capabilities.
GotThumbs - Saturday, September 24, 2011 - link
Curious, So what other laptops use a MagSafe connector? Other than Apple of course.Whats also curious as Anand pointed out. Why did Apple CHOOSE to leave out USB 3? Next years version will most likely include this. Just seems more of the same tactics used by Apple to keep its consumers re-purchasing much of the same technology to gain one or two new features.
Same with Itouch, Iphone, and Ipad. Same IOS, two items (Itouch and Iphone) are identical for the most part, but one makes calls. The Itouch and Ipad are same but one has bigger screen. Just seems like Apple is more about 'reselling' similar products to the same consumers. How many people purchased an IPAD2 to replace their IPAD, so they could have the camera feature? Apple could have added the camera into the first version but chose not to. Apple has great marketing, but I'm just not wowed by it like many others.
I'll be interested in seeing Thunderbolt added to more PC component products.
Constructor - Sunday, September 25, 2011 - link
The display works exactly the same without connecting the MagSafe connector, but the charging function is indeed limited to MacBooks (iMacs and Mac minis also can't use it).And USB3 in all the PCs with Intel CPUs you see right now is always done by connecting an external USB3 controller to the CPU. In Macs the PCIe lines used for that are instead used to drive the Thunderbolt controller, which is much more valuable. Especially on mobile CPUs with their limited supply of PCIe lanes it would probably not even be possible to drive both.
The next generation of Intel CPUs will provide USB3 directly anyway – and Apple will be able to provide both TB and USB3 at the same time.
To the iPad: I've got an iPad 1 and have not felt any compulsion to replace it with an iPad 2, particularly not for the cameras (the much faster processor and lighter weight would have been a better argument).
Apple keeps updating their product lines, and customers decide for themselves when to buy and when not to. Only relatively few actually jump to the next generation immediately. Most skip one or more generations.
Apple was extremely aggressive in hitting their target price of $499 with the iPad, and they actually made it. Just look at the competition and their difficulties in undercutting Apple there.
It is easy to clamour for them to have included everything and the kitchen sink right away, but that is unrealistic for pricing, development capacity and other reasons.
KoolAidMan1 - Sunday, September 25, 2011 - link
There is nothing proprietary about Thunderbolt. The technology was co-developed by Intel and Apple, and unlike USB the mini-DisplayPort connector has no license fees or usage restrictions associated with it. There is a huge difference between being proprietary and brute forcing a new technology that very few others are using at the moment. This isn't the first time Apple dumped legacy connectors in favor of a new technology.Either way, Thunderbolt will be adopted by more and more PC motherboards and laptops in 2012. There is talk of it being a pretty standard part of Ivy Bridge mobos, crossing fingers.
mlrabbitt - Friday, September 23, 2011 - link
Another +1 for the video review. I would prefer this over the "Conclusion" sections of all your reviews.Conficio - Friday, September 23, 2011 - link
I can' see how I have reduced the cables to my laptop now , but all the extensions are still a dangle of calbes, that even the "cable manage" hardly covers.Why is this not offered in a way where you have bays where storage, or other extensions can be hidden into. Or some sort of back mounting system for this.
In the same vain, where is the rest for the closed laptop on this one or the charging of the wireless keyboard?
I'm also missing some bluetooth for those that want to use wireless headsets.
And the future might just cut the second cord by having an inductive charging matt. Although I guess a laptop needs too much power for that.
Constructor - Friday, September 23, 2011 - link
All Macs already come with Bluetooth. Having another BT interface in the display for the same system would just cause interference without any benefit.And where would the inductive charging mat get its power from, if not through yet another a cable...? ;-)
Shadowmaster625 - Friday, September 23, 2011 - link
What happens when you unplug or lose communication with a pci express card while its interrupt is being serviced? Most likely a blue screen of death. It has always been a source of irritation, but that comes hand in hand with being able to buy low cost products. There is no way to code for every possible fault scenario and also meet any kind of budget.Constructor - Friday, September 23, 2011 - link
Thunderbolt-capable drivers will certainly need to survive device disconnection without blowing up the kernel. But beyond that, there should be little need for modification, if any.