The ubiquitous, tiny memory card format is becoming available in increasing capacities. While 256G versions are available, they are expensive due to their recent entry onto the market.
What to do? Why, use a 200G capacity card, of course! Its much lower price point (compared to a 256GB card) and larger capacity over a 128G card offers plenty of space for digital goodies.
The SanDisk Ultra 200GB MicroSD card is a class 10, UHS-1 card that has received much favorable praise for its fast read speeds and reasonable price per gigabyte, but is it compatible with Linux? If so, what are benchmarks like?
Packaging is simple and minimal like most other microsd cards.
The ten-year warranty sounds good, but I have yet to see any microsd card fail.
The 200G Card
Is the SanDisk 200G Compatible With Linux?
The first thing I did was plug the card into a USB 3.0 port using a microsd USB 3.0 card reader(Plugable). Linux Mint 18 recognized the card immediately.
The card ships blank. There is no bloatware or trial software of any kind installed.
Like Linux, the card works without a fuss and offers stable performance. I have not experienced any disconnects or corrupted files during the time I have been using this card and swapping it among devices.
200G – 7% ≈ 183G Usable Space
The card might be labeled as 200GB, but the 7% rule applies. Usable space will be 7% less than the quoted capacity, so expect 183GB of usable free space after formatting no matter what filesystem is chosen. (You will need to set the reserved blocks to 0 if using ext3 or ext4.)
The point is to not have high expectations for 200G of free space as quoted on the package and then feel disappointed after formatting while thinking that your 200G card is defective. It is not. This is typical marketing practice for all kinds of hard drives, USB devices, and SD cards.
I benchmarked the card using a USB 3.0 card reader on different test systems in Linux Mint 18 and Windows 7. Since CrystalDiskMark tests abound online, let’s look at the Windows 7 tests first to see if the card is performing within a reasonable range.
Read speeds show 90MB/s with writes around 20MB/s (FAT32) and 25MB/s (exFAT). From this test, exFAT seems to improve write performance a little.
Disks Benchmark (Linux Mint 18)
Again, we see the slight increase in write speed with exFAT over FAT32 with the SanDisk 200G. Read speeds remain consistent around 86 MB/s.
Disks revealed something other online reviews have demonstrated also: The write speeds start with a bang, but they soon drop to low speeds and remain there.
In both cases, the write graph begins around the 9-18MB/s range, but as the writing continues, writes drop to 4-6MB/s for the rest of the benchmark. While low, this is actually similar to other microsd benchmark write speeds.
This makes me suspect the accuracy of the CrystalDiskMark test and its 20MB/s results. This card might transfer a few files at first at ~20MB/s, but remaining writes continue at a slower 4-6 MB/s. Certainly not class 10 (10MB/s) write speeds. Then again, Disks will always report lower numbers than CrystalDiskMark because they are two different benchmarking programs.
exFAT or FAT32?
From these benchmarks and from everyday, usage, there is practically no real-world difference in performance between exFAT and FAT32. exFAT tended to show a 2-5MB write speed increase over FAT32 in both Linux Mint 18 and Windows 7, However, FAT32 is far more universal and enjoys much greater compatibility with various devices, so FAT32 is my preferred choice.
How Fast Are Real-World File Copies?
To test this, I copied a few thousand miscellaneous files from a mechanical drive (~85MB/s read/write) to the SanDisk 200G connected via a USB 3.0 adapter. Command line was used with time.
time cp -R * /media/thecard
It took 127 minutes to copy 106GB worth of data to the SanDisk 200GB microsd. This averages to about a 13.9 MB/s write speed (almost 14 MB/s). Hmm… This is still a reasonable write speed for a class 10 microsd card, but much higher than the Disks and CrystalDiskMark benchmarks show.
13.91 MB/s * 7620 seconds ≈ 106GB
- 127 minutes = 7620 seconds
- 106GB ≈ 106000 MB
- 106000 MB / 7620 s ≈ 13.9 MB/s
(Read this as: “If you write data at a speed of 13.9 MB/s for 7620 seconds, how much data will you have written?” The result of 105918MB (almost 106GB) is close to the actual 106GB of written data. Calculate 1GB = 1000MB like the SanDisk package does.)
Benchmarks and real-world writes are reporting two different write speeds, but real-world numbers (~14MB/s writes) measured during everyday file writes to the card seem more consistent.
Does the Card Work with the PlayStation Portable?
Two 64G microsd cards in a dual Memory Stick adapter successfully gives the PlayStation Portable (PSP) 128G of storage capacity (118G after formatting) while a single 128G microsd does not work with the PSP. Will the SanDisk 200G microsd work with the PSP?
Like a single 128G microsd card, the SanDisk 200G microsd card is unusable with the PSP.
The SanDisk 200GB microsd is a high-capacity card with fast read speeds. From my tests and everyday use so far, this tiny wonder lives up to its claims and is exactly what I was expecting. True, the write speeds are low, but write speeds from many microsd card are similar. This is still a fast card to read from.
200GB is plenty of space, and approaches hard drive capacity. Think about it, this tiny card has a read speed equivalent to the read speed of a 7200 RPM mechanical hard drive.
For those needing a high-capacity microsd card (greater than 128G) that has excellent compatibility with Linux and ~90 MB/s read speeds, the SanDisk 200G microsd is worth a try.