Best microSD card for Surface Pro 4

Conclusion

Here’s a simple test of my own. This test consists of copying 1.14GB worth of files, 180 of them. Then copy the same files back to the Surface Pro 4 internal hard drive. Obviously, this test is sequential – only one file is being copied at any given time. Once again, each card was fresh formatted before running each test.

Here are the results:

• Samsung 128GB EVO microSDXC (UHS-1): Write – 1 min 12 secs, Read – 52 secs.
• Patriot LX 128GB microSDXC (UHS-1): Write – 1 min 11 secs, Read – 48 secs.
• Silicon Power microSDXC (UHS-1): Write – 1 min 12 secs, Read – 50 secs.
• Samsung 128GB EVO+ microSDXC (UHS-1): – Write – 1 min 11 secs, Read 49 secs.
• SanDisk Ultra 128GB microSDXC (UHS-1): Write – 1 min 12 secs, Read – 47 secs.
• Lexar 633x 64GB microSDXC (UHS-1): Write – 1 min 5 secs, Read 51 secs.
• SanDisk Extreme 64GB microSDXC (UHS-3): 44 secs, Read – 47 secs.

UPDATED on August 9, 2016

I had to re-run all tests again because it was pretty clear that the speed of my Surface Pro 4 SSD drive was impacting the time measurements. SSD cards generally become slower as you fill up its space. When I ran the tests for the first couple of cards, the device was new so there were virtually no other files present except for Windows system files. This resulted in extremely fast write speeds. This is no longer the case hence all cases have been retested.

And the result?

Both the read and the write times are almost the same for all of the above cards with UHS-1 spec. Clearly, for sequential operations, they all hit similar bottlenecks. Even the new UHS-1/U3 card – SanDisk Extreme, reads at about the same speed. This probably means the read speed of the cards are exceeding the write speed of my SSD in the Surface Pro 4. But there is clearly a winner in the write speed race. Clearly, the UHS-3 card wins this race and by a good margin.

This test once again proves that the Surface Pro 4’s sdcard reader is NOT the bottleneck when UHS-1 cards are used.

Kent Beck

Kent Beck is an American software engineer and the creator of extreme programming, a software development methodology that eschews rigid formal specifications for a collaborative and iterative design process. Wikipedia
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