Alik Griffin

Transcend is one of the better memory card brands when it comes to performance. They're UHS-I cards aren't quite as fast as what you can get from Sandisk, Kingston and Delkin, but they are all around decent cards and Transcend is a very reliable brand that has been making memory cards for a very long time. They also have a wide range of cards that run at different speeds for different applications. I only use and test the fastest Transcend cards.

The Lexar 600x has just about the same performance as the 633X but is a touch slower. The 600x is also only available in the U1 speed class where as the 633X can be found as both the U1 and U3 class.  In terms of performance and speed, the card is about average, it's not a very fast card but not slow either. The only reason you would be buying this card is if you wanted something inexpensive for a camera that didn't require high speed memory cards.

The Delkin 633X U3 is an incredibly fast UHS-I SD memory card and gives even the top brands like Kingston and Sandisk a run for their money. The Delkin 633X is often in the top of the list with the in-camera memory card speed tests and Delkin is a very reliable and trusted brand. This makes the Delkin 633X a great buy for those looking for an alternative to the Sandisk Extreme Pro.