“Micro SD Card specifications: SDHC vs SDXC, class 6, 10, & UHS class, R differences speed, or physical too? My Nook HD+ Guide shows 3 types of SD cards are supported: Micro-SD, Micro-SDHC, & Micro-SDXC, The instructions include the following limits: 1) "micro-SDHC cards up to 32GB, Class 6", (no class 10 mentioned.); 2) "micro-SDXC cards up to 64 GB" (class is omitted); & 3) "The UHS speed for micro-SDXC cards is not supported". What is the difference between SDHC class 6, SDXC class 10, & SDXC UHC, What is UHS? Are these “old” guidelines”, are they now interchangeable, and if not, why? Is this a speed issue, a design issue, or is there a physical difference? Under these guidelines, will a micro-SDXC 64GB class 10 (that does not list or include any UHS reference), work? Is UHS-1 the same as Class 10 or something new and "physically" different? If the nook is limited to a 32GB class 6 SDHC card, but can also use a 64GB Class 10 SDXC card, where does this UHS definition fit? The nook info is recent. The limited explanations of SDHC; SDXC, and UHS terms leave me too confused to confidently choose the right SD card for this situation. I didn’t find Class 6 microSDXC cards, will a (faster) class 10' SDXC work, most of them also list UHS, what is the difference? To add the Android to a nook requires an SD card, I’d prefer to use the larger 64GB instead of 32GB. Your guidance would be appreciated. Thank You.”
Answer This Question
1-4 of 4 Answers
The differences are speed and format. The difference between SDHC Clas. 6 and SDXC Class 10 is that SDHC is a FAT32 formatted card with a write speed of 6Mbps, where as SDXC is a exFAT formatted card with a write speed of 10Mbps. SDXC UHS is just a higher speed version with a different specification that is not always supported due to design constraints. The cards are not quite interchangeable. They have made design chages that limits hardware and software accessibility to the full feature of the cards. As for UHS-1, it is the same write speed but uses a different technique to read at that speed. You could get a SDXC card class 10 or lower and up to 64 Gb in size, or the older SDHC Class 6 or lower up to 32 Gb. Hope this helps.
Sorry, there was a problem. Please try again later.If you STILL need this question answered, I'll explain to you: Classes determine how fast the read/write operations can be using a certain card. Your Nook states it supports up to class 6, so it's not a very fast device, as class 6 is a meager 6MB/second read and write minimum, ON THE CARD. So your device can be faster than that, or slower than that. The MicroSDXC classes were omitted because they're likely Class 10 minimum, or UHS-I~III maximum. So they will be a lot faster than your device can handle, that's why the class didn't matter. Like you say "The UHS SPEED for MicroSDXC cards is not supported" Aside from speed and storage size, and brand colors, there's no physical difference between the MicroSD-HC-XC cards. If your Nook supports SDXC cards, you can use 64GB cards, or even 128GB cards for that matter, you'll be OK. Just remember that your Nook will treat them as Class 6 cards because it can't handle more speed than that.
Sorry, there was a problem. Please try again later.HC stands for High Capacity. That standard maxes out at 32gb on average. XC stands for Extra Capacity and can go to 256gb. UHS stands for Ultra High Speed and can transfer data in a fully compatable slot at speeds surpassing 40 mbps. In general UHS is interchangable to XC, and work in ports that support XC standards, but will not use their maximum speed. Class numbers refer to the speed the card can transfer data at. A Class 10 card will work in a Class 6 in general, but if the port is limited to a Class 6 speed, the card will work at that speed instead of the Class 10 rate. The cards will scale down to match a speed, but will not scale up. But a Class 2 card will work in a Class 6 rated port also, but can't get the higher speed. Hope that makes it a tad easier to understand.
Sorry, there was a problem. Please try again later.Currently in my Nook HD I have a 128GB SanDisk Micro SD card with no issues. I also just tried out the Samsung evo 64GB micro SD with no issues. The SanDisk that I normally have in my Nook is: SanDisk - Ultra 128GB microSDXC Class 10 Memory Card Best buy part number: Model: SDSDQUA-128G-A46A SKU: 4471009
Sorry, there was a problem. Please try again later.