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XQD, Ethernet and the Nikon D4  
Wednesday, February 29, 2012 | by Rob Galbraith
Picture quality and autofocus performance will, perhaps more than any other camera traits, determine whether the Nikon D4 is a hit with still photographers. But, these aren't the only indicators that matter, particularly in a camera that introduces built-in wired networking to Nikon's digital SLR lineup for the first time, as well as an all-new memory card format. We have a rundown of the real-world speeds you can expect from the XQD slot and Ethernet port of Nikon's soon-to-be-released flagship camera, with data for CompactFlash and USB 2.0 as well.

XQD and CompactFlash in the D4

The D4 is the first (and only) camera in the world to feature a slot for the new XQD card format, in addition to one for CompactFlash. Announced back in December, the sturdy rectangular card, whose dimensions put it between CompactFlash and SD in size, has an interface to the host device (ie the camera or reader) that's based on the PCI Express specification.

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XQD: Views of the Sony H Series 16GB XQD card and Sony MRW-E80 USB 3.0 reader for XQD, including with SD and CompactFlash cards of the same capacity. Click photos to enlarge (Photos by Rob Galbraith/Little Guy Media)

XQD seems to essentially be a smaller-scale version of Sony's SxS Pro card. It's perhaps not surprising then that the first (and so far only) maker of XQD cards is Sony. Both Nikon and Sony have touted the speed benefits of the new card type, and our initial testing of the H Series 16GB XQD suggests they're right to do so. It's far faster at writing images in the D4 than all of the highest-performance CompactFlash available today, and quite fast at offloading pictures to a computer in the companion Sony MRW-E80 USB 3.0 reader as well (though Lexar's 1000X CompactFlash comes out ahead in this latter test). The following tables illustrate this.

Note: All results in this article should be taken as preliminary, owing to the hurried nature in which we conducted this particular batch of tests (this testing opportunity presented itself smack dab in the middle of several other equally high priority things going on around here). That said, don't expect big swings in any of the numbers once we've had a chance to do the measurements in a more careful manner, nor should you expect changes to any of the conclusions based on those numbers.

In-camera write speed The megabytes-per-second (MB/s) figures in the table below were derived by timing how long it took the D4 to write a 30-frame burst of 14-bit uncompressed NEF photos to the memory card. Timing commenced when the camera's card status light illuminated, and stopped when the light went out. Each test cycle was performed three times. The fastest card is marked in bold.


As the data reveals, the 16GB H Series XQD card outpaces the best CompactFlash by a large margin. Sony's 32GB card is likely to be just as speedy. The data also shows that Lexar's 1000X CompactFlash is at the forefront for this card type, and that the D4 is capable of writing to CompactFlash cards faster than any previous Nikon.

What the numbers don't tell you is the enormous buffer capacity of the D4 and how this mitigates the performance difference between the fast and the really fast cards, as does the camera's juggling of shooting, processing and writing when either extended bursts or frequent shorter bursts are captured.

For example, with the D4 at ISO 800 and set to shoot full-resolution, Fine-compression JPEGs to the Sony 16GB XQD card, the camera was able to rattle off 163 pictures in a continuous 10fps burst before stopping as the buffer limit was reached. That's about 16 seconds of uninterrupted firing, which is tremendous for a 16.16 million image pixel digital SLR. After only a five-second breather, in which the camera freed up significant memory buffer space as it furiously wrote pictures to the card, the D4 was then able to blast through another 133 continuous frames. This is an additional 13 seconds of non-stop shooting.

By comparison, the Lexar 1000X 32GB card allowed 138 continuous JPEGs before the camera stopped firing temporarily. After pausing for five seconds, the D4 went on to snap another 82. This works out to be about 14 seconds of continuous shooting before the pause, followed by another eight seconds after.

So, the XQD card definitely puts up the better numbers, but either it or a fast CompactFlash card enables the D4 to shoot massive quantities of JPEGs without worrying about bumping into the buffer limit. As the table below indicates, the news is almost as good for NEF or NEF+JPEG in the same test, in which the D4 is capable of a still-impressive six or seven seconds worth of pictures before pausing.

This is a camera that can make a lot of frames in one go, regardless of the selected file format. In this way, it's superior to any other digital SLR we've ever tested.


Note: These burst depth counts reflect the D4's capabilities with certain buffer-gobbling settings, such as Active D-Lighting, switched off. Because the camera has plenty of internal memory, though, there is still little risk of buffer stall even when Active D-Lighting is on.

So far, we've talked about XQD speed relative to CompactFlash in Nikon's new camera. That's one perspective, and if you need the best single-card performance possible in the D4, it's an important one. If this describes you, then you'll want to load up on Sony XQD.

But if what you really care about is being able to use both card slots, to increase the total card capacity in the camera at any one moment, to take advantage of D4 features such as writing the same picture to both slots simultaneously, or to simply use either slot without worrying that one slot might slow you down, the point to take away is you can readily do all of this with a pairing of a Sony H Series XQD card and a quick CompactFlash card. The CompactFlash slot is pretty fast, the XQD slot is really fast, and by stuffing the D4 with a huge memory buffer, Nikon has smartly smoothed over differences between the maximum write speeds achievable with each of these card types.

The table below was derived from benchmarking the card-to-computer transfer speed for the cards listed, with the appropriate reader for each type:
The computer was an Apple Mac Pro 2.66GHz/12-core with 16GB of RAM running Mac OS X 10.7.3. Read speeds come from Intech's QuickBench for Mac. We like this software because, unlike many such applications, the results it generates closely match actual card-to-computer transfer rates achievable with the Mac Finder. The fastest card is marked in bold.


Over a USB 3.0 link, the Sony XQD card is really fast, coming in second only to the trio of Lexar 1000X CompactFlash cards. (Sony has also announced an ExpressCard/34 reader for XQD, the QDA-EX1, which we've not yet tried.)

Lexar and SanDisk on the XQD format As discussed, if you're going to purchase some XQD cards in the near future, they're going to say Sony on the label. We know of no other memory card manufacturers that have committed to the format, including pro camera memory card heavyweights Lexar and SanDisk.

In early January, representatives of both companies told us they had no near-term plans to release their own XQD cards. We checked in with each of them again this week, to see if things had changed. Their official responses are below, and can be summarized this way: don't expect to see XQD cards from either maker anytime soon.
  • Lexar's Manisha Sharma, director of worldwide memory card product marketing: "The CompactFlash Association (CFA) recently announced the release of the XQD specification for new high-performance memory cards. Based on the PCI Express specification and designed to serve as a base for future performance scaling, the XQD specification is the third approved standard by the CFA, joining CF6 and CFast 1.1. As is the case with any memory card standard, adoption from camera manufacturers is key to its success. As a leading CFA member, Lexar has been evaluating this technology, and will continue to do so as the market develops to determine if we will offer XQD cards in the future."

  • A SanDisk PR representative: "SanDisk participates in many standards bodies and has contributed to a variety of new standards that allow for options in the marketplace.  At this time, SanDisk has chosen not to productize the XQD format."
D4 Ethernet networking

The D4 incorporates a standard RJ-45 Ethernet jack among the ports grouped on the side of the camera. The Ethernet type is 100Base-T (also referred to as Fast Ethernet), meaning the maximum possible sustained real-world throughput will be a little under 12MB/s. Or at least that's what you can expect to get from a 100Base-T Ethernet link between two modern computers.

The more speed the merrier, because if the link is fast enough it means you can send not just JPEGs but even larger NEF or TIFF files over a local area network (LAN) without bogging down your workflow. Similarly, decent 100Base-T throughput would make the D4's slick new HTTP Server mode that much more responsive and keep its remote Live View from lagging. So, if you want to use the D4's Ethernet port effectively, its speed matters.

Wired Up: The D4's Ethernet port, left, and an FTP transfer in action, right (Photo and screenshot by Rob Galbraith/Little Guy Media)

The D4 is the first digital SLR from Nikon to offer built-in Ethernet, but it's not the company's only digital SLR-related Ethernet product. Wireless Transmitter WT-4, introduced alongside the D3 and D300 and still going strong in Nikon's lineup, has a 100Base-T Ethernet port too. We tested the WT-4 attached to a Nikon D3S, a D4 and its built-in Ethernet plus an Apple MacBook Air 11-inch mated to the 100Base-T Apple USB Ethernet Adapter. The table below depicts the throughput we measured while sending a batch of 30 NEFs to the FTP server of a Mac Pro running OS X 10.7.3, over an Apple Airport Extreme-powered LAN, from these devices. Both cameras were not also shooting while the FTP transfers were underway, meaning their CPUs were fully dedicated to the task of moving pictures out through the Ethernet cable.


The D4's sustained transfer rate is somewhat disappointing. It's not much quicker than the 2007-vintage WT-4, and not close to 100Base-T's upper limit. That said, it does allow for a typical D4 lossless compressed 14-bit NEF, which weighs in at around 18-20MB, to transfer in roughly four seconds. To us, this is just quick enough to be useful.

We also checked out the D4's HTTP Server mode through the camera's Ethernet connection, and the news is all good. The overall responsiveness of the interface when making settings or mode changes is excellent, plus there is minimal lag in HTTP Server's remote Live View in both still and video modes.

This is true when the browser is Safari or FireFox on the Mac and the link through to the camera is entirely wired. Switching to Safari on an iPad 2, and therefore also a mixed wireless/wired connection that's constrained by the iPad's somewhat slow Wi-Fi, there is a bit more remote Live View lagginess. But the overall feel is still peppy and usable.

HTTP Server: Adjusting D4 audio recording levels from Safari on a Mac

USB 2.0

Rounding out the buffet of numbers being served up is a test of the D4's USB 2.0 port. Using Apple's Image Capture application to copy the same batch of 30 NEFs from a card in the camera to the computer over USB took 18.5 seconds, which works out to be a transfer rate of 29.7MB/s. This means the USB 2.0 port in the camera is quite quick (for USB 2.0). By comparison, the identical transfer through the D4's Ethernet port took 98 seconds for, as mentioned, a transfer rate of 5.6MB/s.

Ready to Go: Apple Image Capture

The performance difference between the the D4's USB 2.0 and Ethernet ports is such that, for those times when you can accomplish the very same thing with either one, and you're moving big pictures or lots of pictures over the link, USB 2.0 will be the more efficient option.
Related articles  
Related coverage of this topic includes:
  • Firmware update for Nikon 1 J1, V1 corrects slow motion video bug (May 8, 2012)
  • Comparing detail and moire in the Nikon D800 and D800E (April 30, 2012)
  • Nikon issues recall of some EN-EL15 batteries (updated) (April 24, 2012)
  • Nikon Capture NX2 updated to v2.3.2 (April 24, 2012)
  • Nikon D3200 support added to NEF Codec for Windows (April 24, 2012)
  • Nikon to release AF-S 28mm f/1.8G in May (April 19, 2012)
  • Nikon announces D3200, WU-1a wireless accessory (April 19, 2012)
  • Nikon D7000 disassembled (Update: Canon EOS 5D Mk III, too) (April 11, 2012)
  • Nikon posts user guide for Wireless Transmitter WT-5 (March 31, 2012)
  • Nikon Wireless Transmitter Utility updated to v1.3.1 (March 22, 2012)
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