John Galea's Blog

My blog on Gadgets and the like

UHS SD/uSD cards

The speed of an SD card (or micro SD) is defined by it’s class. Each class means 1MB/s. The fastest class is a class 10 card meaning 10 MB/s. I recently started to notice UHS (stands for Ultra High Speed) on some of the cards with advertised speeds well above 10MB/s and was curious so I did a bit of reading. As usual Wikipedia has an article on it. UHS extends speeds well beyond class 10. So I got my hands on a Kingston Ultimate 64GB (Class 10 UHS-I) microSDXC Card, Up to 90MB/s read, 45MB/s write (SDCA10/64GB) when a friend Lance bought one to put it through it’s paces. This card will present itself as a normal Class 10 card to any system that does not support UHS. In this case you will get speeds close to 10 MB/s. So let’s try it out on some of my gadgets.

Asus Vivotab Note 8 R/W speeds
For reference a class 10 card 9.4/10.3 MB/s
UHS Kingston 18.2/18.1
So clearly it supports UHS but there is a bottle neck. Who knows how the SD card interface was designed but that sounds like a bottle neck inside the system, unrelated to the card itself. Now that said, it’s still almost twice the speed of a class 10 card.

MobileLite G3 USB card reader
Plugged into USB 2 26.6/23.9
Plugged into USB 3 72.1/60.4

Samsung Note 3
For reference a class 4 card 29.6/4.2
UHS 20.2/17.1

Samsung note 8
UHS speeds 13/10
So that’s class 10 speeds with no improvement at all

Asus Transformer
A nice little speed boost.

So as you can see, results may vary. So if you are buying one of these, don’t pay a huge premium for the added speed unless you know for sure you are going to get anything from your specific device. I never did get speeds as high as Kingston spec’d it at.

March 9, 2015 - Posted by | Android, Electronic gadget reviews

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