96 of 103 people found the following review helpful
Works Great for my Galaxy Tab,
Verified Purchase(What's this?)
This review is from: Transcend 32 GB Class 4 microSDHC Flash Memory Card TS32GUSDHC4 (Personal Computers)
I bought this Transcend 32GB MicroSD card for use in my 7" Galaxy Tab. It's a class 4 speed, which means that it has to have a read/write speed that is at least 4MB/s sustained. I clocked mine at around 4.5MB/s to 5MB/s which is consistent with their claims. It's been working well in my Galaxy Tab and I really can't complain. I've had great luck with Transcend brand memory cards in the past. They are cheap, reliable, and high quality cards. I don't think I've ever had one fail on me yet. I like that this card comes with an included adapter that lets you use this as an SDHC card too. This means that you can use it in Micro-SD and regular SDHC devices.
Here is some more information about SDHC cards and speed classes. This excerpt is taken from my own review of the 8GB Transcend SDHC card.
IMPORTANT SPECIAL NOTES ABOUT SDHC MEMORY CARDS:
-SDHC cards are not compatible with most older SD cameras, SD devices, or SD card readers.
-SDHC cards are rated by speed using different "classes". There are currently 4 data transfer speed classes available for SDHC cards. These classes are "class 2, class 4, and class 6, and the new class 10. For example, "Class 2" would have the slowest read/write speed while "Class 10" currently has the fastest read/write speed. So if you have a device in which speed may play a crucial role, make sure you buy a higher "class" SDHC card. Please note that this SDHC card no longer has the fastest read/write speed available. There is now a new class, called "Class 10". Class 6 has a minimum read/write speed of 6MB/sec... while Class 2 has minimum speed rating of 2MB/sec, and Class 4 is 4MB/sec. Starting to see the pattern?
-SDHC cards are not only for digital cameras. Any device that is compatible with SDHC cards should work with this card. Just make sure that it takes a full-sized SDHC card. For example, there are some devices that use smaller cards... like Micro-SDHC or Mini-SDHC. If you have a Micro-SDHC or Mini-SDHC card already and want to use it in a full sized SDHC device, you can buy an adapter that can make those cards larger so that they can fit into a full sized SDHC card slot. However, you cannot make a full size SDHC card fit into a Micro-SDHC or Mini-SDHC slot.
SO WHAT'S THE DIFFERENCE BETWEEN "SD CARDS" AND "SDHC CARDS?
SDHC is basically an upgrade to the older SD cards. The reason they upgraded it was to achieve greater data transfer speeds AND capacity than previously possible with normal SD cards... and to do this, they had to redesign the card (which is why it's not compatible with normal SD devices). This was necessary because digital cameras and digital video cameras these days have higher resolutions, which equate to larger file sizes and faster data transfer needs.
Now that many digital cameras also can record HD video, you may consider getting a larger capacity card because video takes much more space than photos. The size of the video varies from camera to camera depending on what resolution and video compression the camera uses. If you plan on taking lots of video (especially HD video), I would consider getting at least a 16GB card. Check your camera specifications to see how many minutes per Gig of memory your camera can capture ...to gauge how big of a memory card you'll want to get to meet your needs.
Special Note on regular SD Cards:
If you primarily take casual photos and don't need a exceptionally fast read/write capable card, you should know that newer cameras that take "SDHC" cards will also work with older normal "SD" cards. These older cards are cheaper than the new SDHC cards, so this may be something to consider. So to sum things up, newer cameras will take SDHC and regular SD cards, but older cameras that use SD cards may not be able to use SDHC cards. This is because newer technology is usually made to be compatible with older technology (the technical term used to describe this is "backwards compatibility") ... but older technology may not have the hardware necessary to run newer tech (technical term used is "obsolete"... just kidding! ;)
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Showing 1-7 of 7 posts in this discussion
Initial post: Nov 18, 2011 2:31:59 PM PST
This is a really helpful review. Thanks for breaking it down to the basics!!
In reply to an earlier post on Nov 18, 2011 3:12:29 PM PST
Wow! Thanks for all the great info on the different card speeds and card types. I was lost about all the different 'classes' and the differences between sd/sdhc. Thanks for the lessons!
Posted on Apr 5, 2012 5:10:22 AM PDT
M. H. says:
SD cards have a limit of 4GB due to physical pinout. So you'll never see a SD card with a larger capacity.
SDHC cards can go much larger due to physical pinout. There are some other technical internal differences of voltages, timing, etc. If a device does not say SDHC then it probably won't work. Some transitional devices may with a driver upgrade (like my Palm TX).
Note that it's hard to find a 4GB card that true SD (i.e. they're mostly all SDHC) so if you want a 4GB card for a SD only device be sure to very carefully check the specs (vs labeling, ads, etc) and then buy a bunch so you don't have to search again.
Do otherwise consider speed. For example, an inexpensive class 4 card that is 4GB is OK to load up. But consider how long that 32GB class 4 card will take at 4MB/s - more than 2 hours. Or an hour+ for a 16GB card; even the 8GB card is getting annoying to load. So do consider ponying up for a faster card.
Posted on Jul 14, 2012 9:21:04 AM PDT
D. Nalepa says:
There are two types of "speed". Reading from the card and writing to the card. I know of no cases where writing is faster than reading, for the obvious reason that writing requires a change to the card. For viewing pre-loaded content, reading is important, but you still have to download (and write) that content at some point. Similarly transferring from the card (reading) can also be time-consuming with slow read speeds. My opinion is that write speed is most important.
In this, the Class ratings are being gamed by the manufacturers. The write speeds of some Class 10 cards can be well below minimum depending on file size. For the most part it seems that the Class rating is measured on large (100 MB) files - which are directly applicable to video capture (taking movies). For smaller files (for instance a typical photo at 10 MB resolution ) the write speed is typically LESS - and in some cases substantially less. My point is this: assuming a higher Class will give you faster write speeds is *wrong*, especially if you need it for photos and other small files (eg. music). Many of the card reviews on Amazon have "user images" that show benchmark speeds - unfortunately many of those only list speeds with large (100MB) files where we can expect better conformance with the requirements of the industry's Class rating. In general, large SD cards will be faster than micro, and smaller capacity cards will be faster than large capacity cards. Unless your needs are strictly for viewing movies or making videos, the information that you need to make an informed choice has to be hunted down.
Posted on Jul 26, 2012 3:30:28 PM PDT
Amazon Customer says:
Thanks for the details! Good overview!
Posted on May 26, 2013 1:14:42 AM PDT
Last edited by the author on May 26, 2013 1:16:12 AM PDT
So much of that was so wrong. SD and SDHC and SDXC have nothing to do with transfer speeds and everything to do with creating SD cards with higher capacity with different pin layouts. A SD or SDHC and SDXC can all be equally fast or slow and a SD can beat a SDHC in transfer speed because it has zero to do with sped. HC- High capacity XD-extreme/extra capacity
Edit: pay attention to Harris whom at least knows what he is talking about.
In reply to an earlier post on May 26, 2013 3:39:04 PM PDT
Last edited by the author on May 26, 2013 3:43:53 PM PDT
Although you're correct about older SD cards theoretically being able to match the speeds of the newer SDHC or SDXC, the reality is that most of those older cards have slower read/write speeds and the speeds (between different model SD cards) were inconsistent. This meant consumers had to look thoroughly at each cards specifications to see if it was fast enough to meet their needs. Even worst, many older SD cards didn't even state their read/write speeds and only denoted speeds as 10X or 20X speed. For consumers with no technical background, this was probably frustratingly confusing to them. That's why the newer cards started standard "classes" of speed, which helps customers make better decisions. For example, if someone was looking to buy a card for an HD Video Camcorder, I could simply tell them to make sure they buy a class 10 card... instead of telling them to make sure to check specifications on a card which can write at a minimum of 10MB/sec. This also keeps the manufacturers of the cards more honest by requiring them to state the standard speeds of each card they make. Nobody wants to buy an overpriced SD card that has a super slow read/write speed when this is not clearly communicated by the manufacturer. These new speed standards help clear some of the confusion. But yes, it's also true that these newer cards were designed more for increased capacity than for speed. Although I would argue that the newest and fastest SDHC cards far out pace the older SD cards that were available. There are cards now that can read/write up to 95MB/sec. (Sandisk Extreme Pro SDXC I). I don't remember any older SD cards capable of those speeds, but I could be wrong. Find me an example if you can ;)
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