Go Micro-SD Capacity Limit?
- Thread starter Oj37
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- microsd card
In theory - 2TB but not many of those in the wild
City Builder
New Member
I'm currently using a 512GB but the microsd actually is only usable to about 466GB. One has to wonder where that other 50 or so GB went to.
This question still comes up a lot. The reason is that hard drive, SSD drive, and SD card manufacturers inflate the size by counting in a decimal (instead of binary) way. What I mean is that they count, a kilobyte (KB) as 1000 bytes of space, a Megabyte (MB) as one million bytes, a Gigabyte (GB) as one billion bytes. In the computer world things are to the power of 2, so 1 kilobyte, is 2 to the power of 10 (2^10) = 1024 bytes, an MB is 1024 Kilobytes, and a Gigabyte is 1024 Megabytes.
Your drive manufacturer uses the decimal way, and your computer then reads the space and presents it in the binary way.
I do view this as pretty dishonest, since if the drive companies where honest they wouldn't market their drives in increments of the binary system (i.e. SD cards of size 16GB, 32 GB, 64GB, 128GB, 256, 512, 1TB) unless the space also matched the binary size. The actual sizes I think are like 117GB (binary) for the 128 GB (decimal) cards, 233GB for the 256 ones, 466 for the 512 ones. They should really size them and label them in a consistent decimal way, maybe like 15, 30, 60, 125, 250, 500, 1 TB so it would be clear.
I got a SanDisk Extreme 512GB micro SD card to work, which is U3 and A2 compliant, so UHS-2 should work too. I tried the Extreme Pro, which has the same ratings (but has faster read / write) and it was not recognized in the Surface Pro 4 slot, but was via a USB adapter.
Hope this helps!
Snapshot
New Member
No, not supported but a UHS-II card should work at UHS-I speeds.
