SD or Compact flash

NeilA1975

NeilA1975

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Neil
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Have a D800E, currently using Sandisk 32GB ultra cards with 60MB write speed, noticeable slow down in burst shooting just using RAW.
Any benefit in purchasing a faster CF card?

Cheers
Neil
 
Thanks guys - so are we saying SD cards are comparable to CF performance, as long as the write speed is fast enough?
 
Quick google says that D800E won't write to the SD as fast as it writes to the CF, controller rather than the card limiting the speed
 
I recently bought a couple of these http://www.mymemory.co.uk/Compact-F...MB_s-High-Speed-UDMA-CompactFlash-Memory-Card and I've been using them with a 5D3 and a 7D2 and finding no problems keeping a burst going. I also use them for video and have have no problems with them for that either. I also got a couple of these http://www.mymemory.co.uk/SDXC/Lexa...-I-U1-600X-90MB_s-High-Speed-SDXC-Memory-Card to go with the CF cards just in case I wanted to do multiples and I've had no problems with them either. Highly recommended by me, I used to use Duracell 16Gb cards and a couple of Sandisk Ultra 16Gb cards and still have them for my other bodies and backup but I've not used anything other than the Lexar's in my main cameras since I got them.
 
The Nikon D800 series (D800/D800E/D810) only support up to UHS1 SD cards. UHS11 SD cards have a different connection layout which basically adds a second row of contacts which are used to potentially double the throughput. Unfortunately if the camera doesn't have the ability to use those other connections like the D800 series it will just revert to UHS1. UHS11 SD cards may work but you won't gain any benefit over a UHS1 card.
I have been using Sandisk Extreme Pro 90Mb/s UHS1 SD cards in my 800E and now my 810. Having run into some buffering issues on a previous shoot (only on a couple of occasions) I decided to change to CF and went for a Sandisk Extreme Pro UMDA7 160Mb/s.
A quick test on the D810 on some cards I have (all 14bit RAW files, shot at 5fps, 1/1000s and tested 2-3 times on each card)
Sandisk Extreme Pro UHS1 SD 45Mb/s
Number of shots until buffer full: 21-22
Time to take shots until buffer full and write all files to the card: 27s-28s (includes time taken to take shots which is 4-4.5s)
Sandisk Extreme Pro UHS1 SD 90Mb/s
Number of shots until buffer full: 24-25
Time to take shots until buffer full and write all files to the card: 28s-29s (includes time taken to take shots which is 5s)
Sandisk Extreme Pro UMDA7 CF 160Mb/s
Number of shots until buffer full: 27-28
Time to take shots until buffer full and write all files to the card: 27s-28s (includes time taken to take shots which is 5-5.5s)

I then tested the pure write speed by limiting the shots to 20 files and timing from the shutter press until written to the card. The write speeds were 26s (45Mb/s SD), 21s (90Mb/s SD) and 19s (160Mb/s CF).

As you can see there is not a huge difference in timing between the 90Mb/s SD and the CF BUT the CF has written an extra 3 to 4 files to the card in less time than the 90Mb/s SD has managed. Not only has the CF written quicker to the card but you can take an extra 3 to 4 shots using the CF before any slowing down.

So in conclusion what card you use entirely depends on your situation. Sandisk Extreme Pro UHS1 SD 90Mb/s are pretty good all rounder. If you do want quicker though you have to go for CF (a decent CF!), whether you warrant the extra rate is down to your use of the camera, if you've not encountered an issue then stick to a lower rate card.

N.B. the number of shots and write timings may vary slightly if you repeat the testing as the size of the file is dependent on the information in the photo (a photo with little detail will be of smaller file size than a photo with varying detail).
 
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NeilA1975 said:
I actually more interested in the performance of an SD card v a CF card.
Click to expand...

And I'm pretty sure the Canon 5D mkIII is the same, it writes to the SD card slower than the CF. I tend to use Sandisk or Lexar cards and not had a problem with them - certainly what I would recommend,
 
Memory card performance really depends on the camera it's used in. It's a bit like putting fuel in a car, putting the best (most expensive) performance petrol in a fiesta won't make it go any faster, putting the same performance petrol in a Ferrari and you get a car that will go faster than the fiesta.

The d800 limits card read speed so there isn't much point buying faster sd cards. The fast sd card tops out at 38mb/s on the d800 yet the same card does 71mb/s on the d810 and 68mb/s on the d750. If speed is key use only the high performing CF card (fastest CF cards top out at 70mb/s). The d800 wasn't designed as a fast camera (only 4fps and small buffer), its probably only due to lots of wildlife photographers moving to it from the d700 that probably prompted nikon to bring out the faster but roughly the same d810.

Have a look at the link below, it has several cameras tested.

http://www.cameramemoryspeed.com/nikon-d800/fastest-memory-sd-cf-card-tests/
 
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