SDXC SD cards come at a big premium; too bad we can't slide an M.2 SSD into our cameras

Subject: Storage | February 27, 2017 - 05:23 PM |
Tagged: sdxc, sd card, patriot, lx series

You may recall a while back Allyn put together an article detailing the new types of SD cards hitting the market which will support 4K recording in cameras.  Modders Inc just wrapped up a review of one of these cards, Patriot's 256GB LX Series SDXC card with an included adapter for those who need it.  The price certainly implies it is new technology, $200 for 256GB of storage is enough to make anyone pause, so the question becomes why one would pay such a premium. Their benchmarks offer insight into this, with 83Mb/s write and 96Mb/s read in both ATTO and CrystalDisk proving that this is a far cry from the performance of older SD cards and worthy of that brand new ultra high definition camera you just picked up.  Lets us hope the prices plummet as they did with the previous generations of cards.


"Much like Mary Poppins bag of wonders, Patriot too has a method of fitting a substantial amount of goodness in a small space with the release of their 256GB LX Series SDXC class 10 memory card. Featuring an impressive 256GB of storage and boasting this as an “ultra high speed” card for QHD video production and high resolution photos."

Here are some more Storage reviews from around the web:



Source: Modders Inc
Subject: Editorial, Storage
Manufacturer: PC Perspective

What you never knew you didn't know

While researching a few upcoming SD / microSD product reviews here at PC Perspective, I quickly found myself swimming in a sea of ratings and specifications. This write up was initially meant to explain and clarify these items, but it quickly grew into a reference too large to include in every SD card article, so I have spun it off here as a standalone reference. We hope it is as useful to you as it will be to our upcoming SD card reviews.

SD card speed ratings are a bit of a mess, so I'm going to do my best to clear things up here. I'll start with classes and grades. These are specs that define the *minimum* speed a given SD card should meet when reading or writing (both directions are used for the test). As with all flash devices, the write speed tends to be the more limiting factor. Without getting into gory detail, the tests used assume mostly sequential large writes and random reads occurring at no smaller than the minimum memory unit of the card (typically 512KB). The tests match the typical use case of an SD card, which is typically writing larger files (or sequential video streams), with minimal small writes (file table updates, etc).

Speed Class


In the above chart, we see speed 'Class' 2, 4, 6, and 10. The SD card spec calls out very specific requirements for these specs, but the gist of it is that an unfragmented SD card will be able to write at a minimum MB/s corresponding to its rated class (e.g. Class 6 = 6 MB/s minimum transfer speed). The workload specified is meant to represent a typical media device writing to an SD card, with buffering to account for slower FAT table updates (small writes). With higher bus speed modes (more on that later), we also get higher classes. Older cards that are not rated under this spec are referred to as 'Class 0'.

Speed Grade

As we move higher than Class 10, we get to U1 and U3, which are referred to as UHS Speed Grades (contrary to the above table which states 'Class') in the SD card specification. The changeover from Class to Grade has something to do with speed modes, which also relates with the standard capacity of the card being used:


U1 and U3 correspond to 10 and 30 MB/s minimums, but the test conditions are slightly different for these specs (so Class 10 is not *exactly* the same as a U1 rating, even though they both equate to 10 MB/sec). Cards not performing to U1 are classified as 'Speed Grade 0'. One final note here is that a U rating also implies a UHS speed mode (see the next section).

Read on as we decrypt all of the many specs and ratings present on SD and microSD cards!

SanDisk Launches 512GB SDXC Card for $799.99

Subject: General Tech, Storage | September 12, 2014 - 04:08 PM |
Tagged: sandisk, sdxc, sdhc, sd card, 512GB

Assuming your camera, card reader, or other device fully conforms to the SDXC standard, Sandisk has developed a half-terabyte (512GB) memory card. Beyond being gigantic, it can be read at up to 95 MB/s and written at up to 90 MB/s, which should be enough to stream 4K video. Sandisk claims that it is temperature proof, shock proof, water proof, and x-ray proof. It also comes with a lifetime warranty and "RescuePRO Deluxe" recovery software but, honestly, I expect people would just use PhotoRec or something.

It should be noted that the SDXC standard covers memory cards up to 2TB so it will probably not be too long before we see another standard get ratified. What is next? SDUC? SDYC? SDALLTHEC? Blah! This is why IEEE assigns names sequentially.

The SanDisk Extreme PRO UHS-I SDHC/SDXC 512GB memory card should be available now, although I cannot yet find them online, for $799.99 MSRP.

Source: SanDisk