UDMA flash card with Canon 5D?

[robert_hall2]

<p>Has anyone used a UDMA compact flash card with a Canon 5D? <br>

The tech rep at Canon recommended a NON- UDMA compact flash card. (ex: Sandisk Ultra cards are Non-UDMA but the Extreme & Extreme Pro are UDMA cards.) <br>

The issue is not the camera; it writes fast enough for me. The issue is uploading the images to my computer; the Ultra card I currently use is quite slow. <br>

Thanks. </p>

[tom_hamilton1]

<p>I have been using the Lexar UDMA 7 card without any problems. I use a USB 3.0 card reader to upload images to my computer. It is very fast.</p>

[Marcus Ian]

<p>I never had a problem, and I can't think of any reason not to, the nature of CF cards is that it defaults to the speed of the host (ie. when faster, it slows itself down to match the host device interface), unless it's slower, then the host slows itself down to max speed supported by the card.</p>

<p>So even though the 5D can only write @ ~13-15MB/s, my USB3 card reader can transfer files at over 100MB/s (w/ an appropriate card) - with a faster card than mine are, you could hypothetically get up into the ~150MB/s range.<br>

Just remember that <em>any</em> USB2 card reader will likely max out, and give you transfer speeds well into low 2 digits (ie. 15-30MB/s) regardless of the card and or reader (even though the USB2 bus can theoretically support transfers of up to 60MB/s, it an awfully inefficient one :( )</p>

[bobatkins]

<p>As far as I know all UDMA cards have backwards compatibility and function with non UDMA devices. I really don't know why someone from Canon would suggest using non-UDMA cards, unless the non-UDMA cards are cheaper and the tech rep was considering cost. A UDMA card won't help read/write speeds in a 5D of course but it would improve download speeds if you have a UDMA compatible card reader attached to your PC (preferably via a USB 3 connection)</p>

<p>Nikon specifically say that UDMA cards can be used in all their cameras, including early models with no UDMA support.</p>

[robert_hall2]

<p>Thanks to Tom, Marcus and Bob Atkins! Much appreciated. </p>

[robert_hall2]

<p>In a reply from Sandisk that arrived after 1 PM today when I replied above, it appears Sandisk does not even make a non-UDMA card. So even my "ultra" cards which I have been using for years, are UDMA compatible. Hmmmm.</p>

[paddler4]

<p>I've used UDMA cards in a 5D3, a 50D, and a 7D, with no problems at all. My guess is that what the rep meant is that you don't need them.</p>

[Marcus Ian]

<p>Just recall that UDMA is only the 'mode' in which the host device talks to the CF memory card (and vice versa). Using that mode (UDMA7) the theoretical maximum data transfer rate is ~ 167MB/sec. However there are 8 different 'UDMA' interfaces (UDMA0 -> UDMA7)... which vary in max data transfer rate from ~16 MB/sec-> ~167MB/sec. </p>

<p>However, all that means little to nothing in relation to actual read/write performance. That is governed by a) which UDMA mode (or DMA) the two devices use to talk b) the memory controller on the card, and c) the memory chips used on the card. Many cheap and/or knock off cards are fully UDMA7 compatible, but the memory chips are such that write speeds (in particular) are very poor. For example, I've got a Transcend card which I picked up as a spare while travelling (a '400x UDMA7 32GB' card) which can read to the computer (over USB3 reader) at ~110MB, but which will only write at ~30MB/sec. I have Lexar cards (much more expensive) that do ~ 115MB/sec both ways. </p>

<p>In a nutshell, you probably don't need an uber expensive card if the only camera you are using it in is a 5D (or even a 5D2), you would (literally) see near zero benefit (in performance) to using expensive lexar cards (or Sandisk) over a cheap Transcend (or other noname brand) of similar interface.</p>

[robert_hall2]

<p>Thanks, Marcus. Nice detailed reply! I came to the same conclusion as you but for a different reason. (Recall, the issue is uploading many files to my computer is slow.) I do not have USB 3.0 on my computer, just USB 2. I have a spare slot so I could get a USB 3 card, but then I would have to get a USB card reader. A little research revealed I might have to spend several hours installing the USB 3 card because of driver issues. I doubt I would spend that much time uploading my images at the current slow rate. I will probably upgrade my computer in a year or two when Windows 10 is introduced and stable (I gave up being an early adopter years ago.) <br>

<br />I appreciate your response! thanks, again.</p>