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I noticed that the Nikon D4 uses XQD memory cards along side Compact Flash memory cards. What are the differences or advantages of XQD?

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This was downvoted... why? Feel free to msg me in chat. –  dpollitt Jan 7 '12 at 5:49
    
I didn't downvote, but maybe someone figured you could better get the answer from en.wikipedia.org/wiki/XQD_card –  mattdm Jan 8 '12 at 17:41
    
@mattdm - Good point. I always forget about Wikipedia for photo stack exchange! Quite a bit of the info in the answer wasn't in wikipedia at the time of writing anyways. –  dpollitt Jan 8 '12 at 18:09
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1 Answer 1

up vote 7 down vote accepted

XQD is an open format created and licensed by the CompactFlash Association. The interface is based on the PCI Express or PCIe specification, a standard for serial interfaces. The specification was announced on Dec 7th, 2011 in this press release.

The first camera to be announced that uses the format is the Nikon D4. Nikon claims a write speed of up to 125MB/s or 1Gbps in the D4, although this has not been tested independently as of yet. They also claim up to 125MB/s or 1Gbps read speed.

Currently, only 16GB and 32GB capacities are available, through the Sony H Series of XQD cards.

Other specifications noted by the CompactFlash Association:

  • Size of the cards: 38.5 x 29.8 x 3.8mm
  • Interface performance potential: PCI Express 2.5Gbps currently, 5Gbps future
  • Durable & Robust

As a comparison to Compact Flash, the XQD format isn't necessarily faster, but the interface has the potential to be much faster. For example the Lexar 1000X CompactFlash card claims a read speed of 150MB/s and write at 145MB/s, but current cameras can't keep up with this speed as most do not support UDMA7. The Nikon D4 according to the Sony specs released, can keep up at 100 continuous RAW shots.

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Which Nikon D4 spec? Information obtained from Nikon says 90 RAW or 170 JPEG for continuous shooting. –  Itai Jan 8 '12 at 16:12
    
@Itai - That is based on the info here: sony.net/Products/memorycard/en_us/xqd/index.html The ref says "*2 When used with Nikon "D4", with capture of compressed 12-bit NEF (RAW) images. Based on Nikon research." Does that jive or am I reading it wrong? –  dpollitt Jan 8 '12 at 16:59
    
Oh, OK. That is not what Nikon gave to the press but it may be a firmware difference based on when the test was conducted. We will know the truth when the camera ships :) –  Itai Jan 8 '12 at 17:08
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