SanDisk Extreme Pro UHS-II Memory Card Review – Fastest SD Card on The Planet!


At The SSD Review, we test our storage devices slightly different depending upon the device’s marketed purpose.  Our goal is to test in a system that has been optimized with our SSD Optimization Guide, however CPU C State alteration may or may not have occurred depending on the motherboard and BIOS configurations. Benchmarks for our tests are that of fresh devices, so that we can verify that the manufacturer’s specifications match the device. Additionally, we also try to include links to the benchmarks used in our report so that you as the reader can replicate our tests to confirm that your device is top-notch.

System Feb 2014


This Test Bench build was the result of some great relationships and purchase; our appreciation goes to the below mentioned manufacturers for their support in our project. All of the components we use for testing and evaluation can be easily purchased at a relatively affordable price. The links provided below can assist in pricing, as well as availability for those of you who may find interest in our equipment.

PC CHASSIS: InWin 901 Mini-ITX Chassis
CPU: Intel i7 2600 CPU
CPU COOLER: Corsair H80 CPU Cooler
POWER SUPPLY: Cooler Master M2 Silent Pro 850W
SYSTEM COOLING: Corsair Chassis Fan
MEMORY: Crucial Ballistix Tactical Tracer 1600 MHz


The software used for today’s analysis is typical of many of our reviews and consists of Piriform SpeccyATTO Disk Benchmark, Crystal DiskMark, and Quickbench.  In consumer reports, we prefer to test with easily accessible software that the consumer can obtain, and in many cases, we even provide links. Our selection of software allows each to build on the last and to provide validation to results already obtained.


Piriform Speccy is a great tool for checking the status and health of your computer system. It provides you with brief summary, or a detailed look, at your operating system, CPU, RAM, motherboard, graphics, storage, optical drives, audio, peripherals and network.

Sandisk SD Card and Reader

Speccy shows us that the SanDisk SDHC card has a total capacity of 16 GB, yet the actual amount usable storage is 14.2 GB. Since the capacity is less than 64 GB, we can see that the file format is FAT32, greater than 64GB we would see exFAT as the file format.


ATTO Disk Benchmark is a relatively easy-to-use benchmark tool, which happens to be the benchmark of choice for many manufacturers. ATTO uses compressible data rather than random data, which results in higher performance and thus, higher benchmark scores. In our testing, we have selected the transfer size to range from 0.5KB to 8192KB, and have set the total length of the test to be 256MB.


Our first benchmark test looks at the performance of the SD card using compressible data, where we can see that the read speeds reached 245 MB/s and the writes speeds reached 193 MB/s. Ok, so not as high as what is listed on the packaging, but … where else are you going find an SD card with read and write speeds this fast? It’s pretty astonishing to see.

You might also notice that we don’t see the full performance of the SD card until we reach 8K file size. This is similar with all SD cards.  Unlike the typical system SSD, SD cards are not used for the storage, execution and saving of smaller system files.  SD cards are built for larger media files such as photography and video, these files being highly incompressible in their makeup.


Crystal Disk Benchmark is visually straightforward, and is used for measuring the speeds at which your storage device reads and writes in both compressible (oFill/1Fill) and random, mostly incompressible, data. Random data is more consistent with everyday use of a computer, such as transferring videos, pictures and music. We run the benchmark twice, using oFill data first, and then proceeding to test with random data. Since results typically return with nearly identical scores, we only include the results for random data samples.


Now switching over to incompressible data as our test samples, we can see that the SanDisk SDHC card still performs at an elite level. We can also see similar performance at the 4K level as we saw in ATTO. SD cards are designed and manufactured with the transferring of large incompressible data files in mind, so they perform much faster at higher file capacities.


Anvil Storage Utilities is essentially an all-in-one tool for all of your SSD benchmarking needs. Anvil can be used for basic consumer testing, as well as endurance testing and threaded I/O read, write and mixed tests. It displays data regarding the SSD, and even about your system.


With our Anvil Storage Utilities benchmark test, the SanDisk SDHC card received a read speed of 230 MB/s and a write speed of 183 MB/s, these are the lower level of speeds we have seen thus far throughout testing. However, the results are still coming in much faster than we could have ever have imagined. The SD card also achieved a total score of 631, which is pretty decent for a SD card.


  1. It seems the bottleneck for most current DSLRs, including the 6D, is the controller card. So if you were to test the write speeds of the cards in the cameras, you’ll find that 50MBs will be the write speed limits so any card with a minimum write speed higher than that is superfluous on the currents cameras. The in-camera benefits of UHS-2 cards will not come until at least the next generation of semi-pro Canon or Nikon DSLRs. So far only the Fuji X-T1 will take advantage of UHS-II.

  2. Wow, thats a wicked fast card. Too bad, pretty nothing supports UHS-II at the moment ;(

  3. Writes and smaller reads are still limited by low IOPS. Sure a benchmark can get >180MBps with large sequential blocks but the smaller+random IOPS rates mean it is FAR FROM being SATA SSD performance.

  4. Is there a currently selling camera that has these additional contacts (UHS-II), to take full advantage of this card?

  5. Could the bottleneck be the operating system? Windows 7 does not support USB Attached SCSI. This command set can significantly speed up flash storage access over USB by allowing commands to be queued, allowing the controller to execute them back to back instead of waiting for another command to be sent when the previous command is finished, and also allows the controller to execute commands out of order if that can be done safely and can speed things up. Windows 8 and later support USB Attached SCSI.

  6. SanDisk and Kingston makes some of the best SD and Micro Sd cards on the market I have had my SanDisk for years, 2 of them with no issue.

    R. Gardener:

  7. Thanks. Such SD memory card is really helpful for me to store my phone photos and files.

    Hope it is not too expensive.

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