Is It Worth Paying Extra For Fast SD Cards?

Barence writes "Are faster grades of SD memory card worth the extra cash? PC Pro has conducted in-depth speed tests on different grades of SD card to find out if they're worth the premium. In camera tests, two top-end SD cards outshone the rest by far, while class 4 cards dawdled for more than a second between shots. However, with the buffer on modern DSLRs able to handle 20 full-res shots or more, it's unlikely an expensive card will make any difference to anyone other than professionals shooting bursts of fast-action shots. What about for expanding tablet or laptop memory? A regular class 4 or 6 card that's capable of recording HD video will also be fast enough to play it back on a tablet. The only advantage of a faster card for media is that syncing with your PC will be quicker. However, a faster card is recommended if you're using it to supplement the memory of an Ultrabook or MacBook Air."

Comments

Not just for professionals...

[The Living Fractal]

As an avid amateur photographer I once tried lower-end, slower SD cards. The wait between shots of ~1 second (disregarding the camera buffer) means you cannot even preview your shots during that time. Instead you get to wait with a nice blinking LED on the back of the camera until the preview is ready. I found this nearly unbearable after only a dozen or so shots and when I got a chance I immediately spent the money on a faster card that allows previews basically immediately. NOTE: I am using a D800, so your mileage may vary on this... with 36mp RAW files I was waiting several seconds to just preview a shot.

Re:Not just for professionals...

[maz2331]

I use a D5100, and even with its 16mp RAW files, I always use a Class 10 card to make its responsiveness decent when shooting more than one shot. Cards are cheap, time and missed shots are more important.

Re:Not just for professionals...

[Intrepid imaginaut]

Never mind cameras, try hauling a few gig of files on or off your ebook reader on anything less than a class 10. Yes indeed, my time is worth a lot more than the few bucks extra, if it finishes at all.

Re:Not just for professionals...

[fuzzyfuzzyfungus]

Both CF and SD include the controller: CF cards actually look like PIO IDE drives, on a mechanically different connector, and SD is its own thing. Now, for whatever strange reason, the SD spec guys really skimped on maximum size(there are a few oddball 4GB, with some quirks in certain devices, with 2GB or less being the rule), while the CF spec didn't(not sure about 48-bit LBA in older devices; but that much Flash used to cost more than a new car, so who's checking?)

If they'd just found an extra penny or two in the budget for a higher capacity ceiling in the first place, the whole 'SD'->'mechanically identical and wholly incompatible SDHC' transition could have been avoided.

Re:Not just for professionals...

[Solandri]

Class 10 is a measure of sequential write speed. Nothing more. Cards which are tuned for high sequential write speed (i.e. class 10 cards) suffer from low random 512k and 4k read/write speeds. And cards which are tuned for better random 512k and 4k read/write speeds suffer from lower sequential write speeds. It's a trade-off made when designing the card.

Here are the CrystalDiskMark scores I got for a 32 GB class 4 card I have:

seq: 22.9 MB/s read, 4.3 MB/s write
512k: 22.0 MB/s read, 1.3 MB/s write
4k: 3.3 MB/s read, 1.3 MB/s write

And here are the benchmarks for a 16 GB class 10 card I have:

seq: 21.8 MB/s read, 12.0 MB/s write
512k: 21.5 MB/s read, 0.9 MB/s write
4k: 5.7 MB/s read, 0.008 MB/s write (not a typo)

So if you're recording video or a burst of photos from a camera, yes you want class 10 (or one of the "pro" cards which write even faster). But if you're going to be using the card to read/write lots of small files, like on a phone or tablet, you don't want class 10. For those devices, the sweet spot is around class 6, or maybe a good class 4.

try hauling a few gig of files on or off your ebook reader on anything less than a class 10

I've actually done something similar on both the above cards. I have an ~4 GB sheet music library (put it together when it wasn't clear if IMSLP would survive the copyright challenges). Most of the files are 100k to 1 MB PDFs, with a smaller number of 1-10 MB PDFs (small in number, but not in total MB). Average size is just under 1 MB. Copying the whole thing to the class 4 card took about 30 minutes. Copying it to the class 10 card took about 4 hours.

Uhm, yes and WTF?

[Maxwell]

"However, with the buffer on modern DSLRs able to handle 20 full-res shots or more, it's unlikely an expensive card will make any difference to anyone other than professionals shooting bursts of fast-action shots"

UHm, no. Top of the line SLR can't handle 20 shots in buffer, and any consumer grade is 1-2 max. You won't get you 3-5 FPS (mid tier) or 5-9FPS (high end) without a fast card. And don't even think about recording 1080p or 720p@60 without a class10 UHS1 type card. The whole PC PRo exercise is a useless article apparently trying to convince consumers to buy slower things because 640k is enough for anyo....oh wait we've heard this before, haven't we :). I'd love to see them record HD video on Class4 card. Not happening.

Buying a class 4 or 6 card is just stupid these days. That is the PC equivalent of actively seeking out a USB1.1 portable HDD instead of USB3. Because USb 1.1 is all the speed you'll ever need really.

You will never regret buying class 10, but you will almost certainly regret a class 6 so why bother? Heck, in a year or two there won't be any class 6 available anyway - it is too slow...

Cameras: Canon EOS550d, S90.

what about normal consumer point-and-shoot?

[AxemRed]

While modern DSLR cameras might have large buffers, normal consumer-grade or even enthusiast-grade point-and-shoot cameras don't necessarily have them. IMO it makes sense for an average person to buy a higher speed card. They're probably only buying one card anyway, and the price difference between a slow card and a fast card is small enough to make it worth it.

Not according to the guy at frys

[joeflies]

I once went to frys to pick up some extra cards, and the sales rep told me that if I buy the more expensive cards, it will improve the quality of my pictures because they will be sharper and more colorful. I am still trying to figure out how he justifies that statement.

Re:Not according to the guy at frys

[Sqr(twg)]

That's bullshit! You won't even notice the difference unless you use a Monster Cable.

Find the card that suits your needs.

[rusty0101]

For Photography, work out your budget, figure out what you need for your style of taking pictures, and buy the best memory you can afford for your needs. If you can get by with class 4 or class 6 memory, great. If you find that you need class 10, try out some of the budget options noted above and see if they serve your needs.

For other uses, you may very well find that a slower card actually works better for you than a 'faster' card. Class 10 is great for streaming large volumes of data onto the card, but experience has shown in the microsd cards that if you need to do a lot of small file manipulations, read and write, etc. a class 4 may outperform a class 10 card. This is of interest to people doing cyanogen mod implementations running off of the sdcard, but is a completely different use case from a photographer shooting high res photos, or a videographer shooting HD video.

Video and SD speed ratings

[MasterOfGoingFaster]

I've learned through trial and error what cards actually work on my camcorder. For still photography, I've always been a SanDisk fan. But every class 10 SanDisk SD card I have used is unable to support the highest quality recording on my Canon camcorder. Oddly, class 10 Transend cards work fine. It appears the class 10 rating is a read-speed rating - not write-speed. I've tried 6 different SanDisk cards over the years and they continue to disappoint.

Re:I've found reading is faster than writing anywa

[Intrepid imaginaut]

I used to have an old 7" netbook for my daughter to use (I've updated her since).

Ah pubescence 2.0, them were the days.

Re:yes

[icebike]

It will when you record highres video

From the article (first page, you should have spotted it)

It may seem counter-intuitive that capturing still images requires a faster card than shooting video, but Full HD footage isn’t as space-hungry as you might imagine. Despite the “high-definition” terminology, each HD frame has a comparatively low resolution of just over two megapixels. Plus, since consecutive frames of a video are often extremely similar, clever compression techniques can be used to store moving images efficiently. A data rate of 4-6MB/sec is ample for continuous shooting.
Still photographs have a far higher resolution: a typical consumer DSLR may capture around 12 megapixels of detail, and high-end models often record more than 20 megapixels. Each scene may therefore contain ten times as much information as a comparable video frame

Raspberry Pi?

[Matt_Bennett]

Since SD cards are the standard storage medium for the Raspberry Pi, what about a speed comparison for that?