Testing the latest crop of U3/UHS-1 SDXC cards in a 6D

[majorcatch22]

I need to upgrade to faster storage medium for my 6D.

If anyone is using one of the newer U3/UHS-1 cards, would you mind posting a simple test for me.

1.  Type of card.

2.  At 4.5 frames/second, please specify the number of RAW (not mRAW or sRAW) images that the camera will complete before it slows down (buffer full).

3. If possible measure the camera reduced frame rate after the buffer fills.  Count 10 frames after the buffer is full while watching a clock with a second hand.  (12 seconds for 10 frames is 1.2 frames/sec).

4.  How long does the buffer take to empty after you release the shutter button.

I tested my Patriot LX series 32GB class 10 SDHC cart and had the following results:

14 frames at a full 4.5 frames/sec.

20 seconds for the next 10 frames = .5 frame/second.

32 seconds to clear the buffer after shutter release (light off).

I was shooting the wall clock I was using to time with for this sequence.

I'm looking at the Transcend 64GB U3/UHS-1 (claimed write speed of 60MB/sec.).

Thanks for taking the time to test and posting the results.

6D, 17-40L, 70-200L 2.8 IS, 50 1.4, 85 1.8, 50 2.5 macro

7D, 17-55 2.8 IS, 60 2.8 macro

[cicopo]

That's a slow card. Write speed is the important spec. Here's what I'd be ordering which for now is overkill but you don't know what your next upgrade might be.

http://www.bhphotovideo.com/c/product/1030992-REG/sandisk_sdsdxpb_032g_a46_32gb_extreme_pro_sdhc_uhs...

[cicopo]

You might find this interesting

http://www.cameramemoryspeed.com/canon-7d-mark-ii/fastest-sd-cf-card-comparison/

According to it my recommendation wasn't very good & better yet I own 3 of the best SD cards they tested in the 7D2 and 2 of the CF's. Guess I'm good to go when I buy a 7D2.

[majorcatch22]

Hi Cicopo,  thanks for your input.

I had found this website earlier today.  The author is kinda biased towards Nikon (7 different models) and only one Canon.  Never the less still an awful lot of useful information presented.  Looking at the Nikon D600 tests. I suspect it and the Canon 6D are very similar in the speed of their UHS-1 interface.

Another interesting site is:

http://www.thessdreview.com/hardware/flash-drives/samsung-pro-microsdxc-uhs-1-u1-card-review-64gb/3/

The author has done in depth testing on a number of the newer SDXC cards.  He concludes his articles with a "real world write test" using a Canon 6D (lucky me).  The test is fairly simple, count the number of frames @ 4.5 frames/sec until the buffer fills and then time the buffer offload.

What I got from both sites is the new Samsung Pro offers the biggest bang for the buck (2 more frames/sec in the 6D. before the buffer fills over the SanDisk Extreme).  According to their website the cards are hardened much like the SanDisks, but doesn't say anything about ECC circuitry.

If anyone has any input or opinion of the Samsung Pro vs the SanDisk Extreme please do.

[majorcatch22]

Update:

Ordered a couple of SanDisk 64GB Extreme Plus U3/UHS-1 (yellow label) cards from Amazon  this weekend for $48 each.   They shipped me a pair of the older 64GB Extreme U1/UHS-1 (black label).  Befpre I blew a gasket, I read the fine print on the sealed shipping material and it said that the card should perform upto 80/MBs read and 60/MBs write.  Since that's what I was looking for I decided to test one of them.

These are real world figures on a Ubuntu 14.04-x64 LTS system moving appox. 32GB of a mixture on Canon 6D raw and jpg files, using a Transcend RDF5 USB 3.0 reader:

Write speed = 62/MBs

Read speed = 53/MBs  (not sure why reading is slower than writing, might be a function of Linux handling the exFAT file system.

In my 6D I had the following results:

1. At 4.5 frames/sec fired off 20 raw images (average 22.4MB) before the buffer filled up.

2.  Camera continued to trip the shutter every 0.8-0.9 seconds.

3.  After the last shot was taken, time to empty the buffer was 8 seconds.

4.  At 3.0 frames/sec (quiet shutter mode) was able to fire off 28 raw images before the buffer filled.