SD Cards – Are All Things Created Equal
Memory card manufacturers are always touting the latest and greatest cards with ever increasing speeds, but does it really matter how much you spend on a card. To put this idea to the test, we took a handful of different cards and used CrystalDiskMark to test the read and write speeds of the different cards. Continue reading to see how low-budget generic cards stood up to the top brand name’s cards.
The Cards
The cards that were tested are all very affordable being SD cards and included:
- Kingston 16gb SDHC Class 10
- MicroCenter 16gb Class 10
- Sandisk 16gb Extreme SDHC Class 10
- Eye-Fi Pro X2 16gb Class 10
The Testing
The testing was all done on an Alienware i7 laptop using the built-in SD card reader. The software used was CrystalDiskMark. The test settings used the default of 5 tests at 1,000MB. The sections below are as follows:
- Seq : Sequential Read/Write Test (Block Size = 1024KB)
- 512K : Random Read/Write Test (Block Size = 512KB)
- 4K : Random Read/Write Test (Block Size = 4KB)
- QD32 : Random Read/Write Test (Block Size = 4KB, Queue Depth = 32) for NCQ&AHCI
Test Results
| Card | Price | SEQ Read |
SEQ Write |
512k Read |
512k Write |
4K Read |
4K Write |
QD32 Read |
QD32 Write |
| Kingston | $16.98 | 23.27 | 14.52 | 22.29 | 0.544 | 3.351 | 0.113 | 2.464 | 0.072 |
| Micro Center | $14.99 | 21.90 | 10.47 | 21.85 | 1.758 | 8.283 | 0.018 | 8.697 | 0.020 |
| Sandisk | $18.99 | 23.66 | 23.02 | 23.09 | 1.541 | 5.239 | 1.490 | 4.538 | 0.473 |
| Eye-Fi | $99.99 | 12.10 | 11.75 | 11.99 | 1.705 | 5.095 | 1.372 | 5.813 | 1.702 |
Interpreting the numbers
I was actually a little surprised at the numbers as I expected more consistency across the board. As you can see, difference cards performed differently, and sometimes drastically, from each other. Generally speaking, the Sandisk card will have the best overall performance for use in a camera….you would think.
To validate the data, I then used a MacBook Pro with Black Magic Disk Speed Test and redid all of the tests and got the following results:
| Card | Write Speed | Read Speed |
| Kingston | 15.3 MB/s | 20.3 MB/s |
| Micro Center | 7.7 MB/s | 14.4 MB/s |
| Sandisk | 12.9 MB/s | 19.3 MB/s |
| Eye-Fi | 8.4 MB/s | 19.0 MB/s |
Using the Black Magic Speed Test the Kingston reigned supreme with the Sandisk coming in a close second. The Micro Center generic card came out on the bottom and the expensive Eye-Fi card had really bad write speeds but quite fast read speeds.
What does this tell you, it tells you not all cards are created equal and often times you do get what you pay for as higher end cards generally have better performance than lower end budget cards
thanks for the test,
by the way, i use buy the kingston and sandisk both in the past, and skipped kingston for the reason they started to show card error on the camera while shooting a few times, (CF cards) on my canon slrs, and those cards had more problems with my nikon dslr.
now i buyy either the lexar or sandisk.it´s worth the price you pay.
Its worth noting that some cards such as the sandisk and Transcend come with lifetime warranty. Just register yur card on their respective web sites. This will also valdate that the card is genuine product and not a fake.
stuart chard http://www.stuartchardimages.com/blog
Thanks for thorough testing Kerry!
So I wonder how Sandisk can rate their cards at 45mb/s?
One other point that is also important is the quality of the SD cards plastic shell's as they are definitely not built to the same specs. I have an Eye-Fi 4gb and few Patriot class 10 cards and they all have developed splits or crack quite quickly. The few Sandisk SD's that i've collected over the years seem to hold up better and the shells feel more solid.