ProGrade Digital 650GB Cobalt 1700 CFexpress B Card & Dual Slot CFexpress/SD Card Reader Review



Having tested a number of CFexpress Type B cards to date, it is nice to see that high temperatures seem to be becoming the exception rather than the norm.  All ProGrade Digital CFexpress Type B cards tested had low temperatures that we would expect to see become the norm.

This chart shows the cards we have tested and the temperatures each have reached during sustained write data transfer. Anything in the area of 80°C leaves ones camera rather hot to the touch and you definitely don’t want to be removing the CFexpress card right away. 45°C-58°C is normal. It may leave the camera a bit warm but the card can be removed or switched with another.


Our sustained write performance of the ProGrade Digital 650GB Cobalt 1700 CFExpress Card was 1.31GB/s.  We test this by transferring an 85GB 8K media folder to the CFexpress card and obtaining the speed at about the 85% mark once it has leveled off for some time.

With our previous reviews of the SanDisk Extreme Pro and the Lexar Professional CFexpress Type B Cards, we were rather impressed with the sustained performance that we were seeing, topping 1GB/s in fact. The ProGrade Digital 1700 Cobalt is our top result to date, but that 650GB Cobalt isn’t far behind.

This is a great time to see exactly what we mean by differing sustained write performance not being recognizable in normal testing.  Check out the sustained write of the first place card, the Prograde 1700 Cobalt, compared to the other end of the spectrum with the ProGrade 1700 Gold at 357MB/s.  Would you believe these have almost exact specs with respect to ‘peak’ performance?  Don’t get me wrong.  As much as that 1700 Gold CFexpress card may be the slowest on the chart, it performs fine in digital cameras, has an excellent reputation… and is an amazing 1TB in size.


For our Real World File Transfer Comparison of the world’s top CFexpress Type B cards, we have included all cards that we have received to date. This test is conducted through the transfer of data from one spot on the test drive to another to give us the truest of transfer speed results for that device.

Not only did both ProGrade 1700 Cobalt CFexpress B cards have the best showing of all drives tested thus far, but also, their small file OS transfer times were out of the park.


The ProGrade 650GB Cobalt 1700 CFexpress Card just might be the best CFexpress card on the market today.  With speeds in the area of 1650MB/s read and 1420MB/s write and 300k IOPS, this card even pulls off 1.3GB/s sustained writes while maintaining an average temperature of 47°C.

The card comes with a laser-etched serial number on the back for additional security and software is available to keep the card in top running shape, as well as for any recovery needs one might encounter. Pricing for the 650GB version of the Cobalt 1700 on Amazon right now is $749 which is right around what we might expect for this capacity.

We also spoke about and took a look at the ProGrade Digital USB 3.2 Gen 2 CFexpress B/SD Card Reader which is a great alternative to those that haven’t got Thunderbolt 3, USB 3.2 Gen 2 becoming the norm in today’s PC systems.  It is available, as well, on Amazon for $79.99

In consideration of the performance and temperatures displayed by the ProGrade Digital 650GB Cobalt 1700 CFexpress Card, and the incredible build of the CFexpress/SD card reader, we are awarding these products our Editor’s Choice Award.


ProGrade 650GB Cobalt CFexpress Card Ratings

Product Build
3-Year Warranty
Pricing and Availability

Cool Running!

The 650GB version of ProGrades Cobalt 1700 CFexpress family provides top speeds to include sustained performance, maintains great temperatures, comes with a three year warranty, as well as additional software availability at a decent price.

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  1. What speeds did you get with ProGrade Digital USB 3.2 Gen 2 CFexpress B/SD Card Reader?

    Waiting for Angelbird cards and reader tests!

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