📅 August 8, 2018
MicroSD cards continue to increase in capacity, decrease in price, and increase in speed.
I purchased my own PNY Elite-X, and here are my results.
(Nobody sponsors this. I am only sharing my results when using it with Linux in case this knowledge helps somebody else. The link to Amazon is a paid link intended to help others locate the item and to help support the time writing this article.)
Sure there are other factors at play that affect speed, but guaranteed minimums would be a huge help.
The Card Itself
UHS-I and U3
Actually, there are guaranteed minimums printed on the box that we can use to find out the minimum write speed that the card should perform at.
Notice the U3 (3 in the letter U)? This is the UHS (Ultra High Speed) write speed rating that guarantees a minimum write speed of 30 MB/s. The real-world performance might be higher, but 30MB/s for writes should happen with this card.
The C10 refers to Class 10. This is an SD designation that guarantees that the card will write at least 10MB/s.
The uppercase “I” marks this as a UHS-I microSD card. UHS refers to the bus interface, not the read/write speed. UHS-I is what most people are probably familiar with. If you look on the back of the card, there is only one row of contacts. A UHS-II card (denoted by “II”) would have two rows of contacts.
UHS-II cards are much, much faster than UHS-I cards and can usually reach ~250MB/s for reads and writes, but they are also much more expensive. The PNY Elite-X is a UHS-I card, and it costs less.
Notice that the formatted capacity is 236GB, not 256GB as mentioned on the package. This is another marketing trick found on almost every hard drive, SSD, and storage device sold. Just note that the card is not defective. This is normal.
The card ships empty. There is no bloatware or software of any kind preinstalled.
CrystalDiskMark 6.0.0 (Windows 7)
First, I tested the card in Windows 7 using CrystalDiskMark 6.0.0.
So far, I would say that the box claims are close to actual performance. Next, let’s see how this performs in Linux Mint 19 Cinnamon using the built-in Disks benchmark.
For comparison with the 5x100MiB test from CrystalDiskMark.
For comparison with the 5x1000MiB test from CrystalDiskMark.
Real World File Transfer
Benchmarks are fine, but what can we expect when transferring files from a mechanical hard drive to the PNY Elite-X via USB 3.0?
Here, I transferred about 230GiB of various files of varying sizes to the 256G PNY Elite-X microSD card using time rsync.
To calculate bytes written for verification, convert 80 minutes into seconds (80 * 60 = 4800 seconds). Then, multiply 4800 seconds by the rate 48,000,000 bytes/second (rounded). This results in 230,400,000,000 bytes, which is close enough to the source total.
Total bytes transferred = (seconds)(bytes per second)
230,400,000,000 bytes transferred = (4800 seconds)(48,000,000 bytes/second average)
I am happy. The PNY Elite-X microSDXC card was a worthwhile purchase that met my expectations. While I never reached the “up to” 100MB/s read speed printed on the package, I would say that 85-90MB/s is fairly good for read speeds.
The writes are where the PNY shines. At 60-68MB/s for write speeds, this becomes important if you find yourself updating a microSD card with new data frequently, and it definitely beats the measly 5-17MB/s write speed of the Samsung EVO Plus if transferring small files. I would certainly recommend the PNY Elite-X over the Samsung EVO Plus because of this. In addition, the PNY Elite-X average access times were almost half those of the Samsung EVO Plus in every test.
From my everyday usage, the PNY has become my favorite microSD card since it writes in less time than the Samsung. This saves real-world time.
The technology of today has improved greatly. Think about it. We now have itty-bitty, teensy-weensy solid state cards the size of a small fingernail that hold more data and perform faster than bulky mechanical 7200RPM drives from a few years ago. Impressive.
Best of all, the PNY is 100% compatible with Linux out of the box.