Sonnet SF3 CFexpressB/XQD Pro Thunderbolt 3 Card Reader – All that Speed!


Crystal Disk Benchmark is used to measure read and write performance through sampling of random data which is, for the most part, incompressible. Performance is virtually identical, regardless of data sample so we have included only that using random data samples.




The above result tests the SanDisk Extreme Pro 512GB Cfexpress Type B card with both the Sonnet SF3 and SanDisk CFexpress Card Reader.  Remember, data is being read from the CFexpress Type B card and not written to, so these read speeds are very important.


Having said that, we thought it just as important to validate data transfer speeds for this drive, in comparison to that of the AIC card that we were using with the integrated CFexpress card shown above.  The only reason we wanted to test this is for our future CFexpress testing directly from the Sonnet SF3, rather than popping our integrated Cfexpress AIC solution in and out of the system.


A rather interesting result…  If you look back at our report of the SanDisk Extreme Pro, you will remember that we had noted that they had set this SSD to thermal throttle to a lower speed around the 65C mark.  This is what has occurred here.  The card had maintained just under a sustained transfer rate of 800MB/s for the first part, suddenly dropping back down to that 453MB/s mark.  No fault of the card whatsoever as it is still much higher than the in-camera maximum write speed, and as well, we pushed it a bit before this test as we wanted to demonstrate thermal throttling once again.


The Sonnet SF3 Series CFexpress B/XQD Pro Card Reader is one of the few on the market today that will allow you to use your CFexpress card to its full performance capabilities.  Its build is beyond reproach with a smooth brushed aluminum exterior with ribbing that acts as a heatsink, two ports in the front that will accommodate CFexpress Type B or XQD cards, as well as two Type-C Tbt3 ports at the back to allow for daisy chaining as Thunderbolt 3 does.


The SF3 comes with a .5m Tbt3 Type-C cable that worked fine and we found that our Plugable .8m cable worked fine as well.  The SF3 comes with a two-year limited warranty, lifetime technical support, and we were rather impressed with the ThunderLok connector that allows for a secure Type-C cable fit onto the device.  Our testing proved that the Sonnet technology SF3 gave identical results to our AIC card and left us with the belief that it provides true Thunderbolt 3 data transfer rates, regardless of the card used in the reader.

Last but not least, we will be the first to say that the SF3 is expensive.  It is a premium build that was envisioned initially for camera professionals holding something like the Canon 1DX Mk III that happens to house two CFexpress type B cards. We simply now find ourselves with the canon R5 at the enthusiast level, not to mention other brands using XQD.  Amazing gear Sonnet!

Check Sonnet SF3 CFexpressB/XQD Card Reader Pricing at Amazon


Sonnet SF3 Series CFexpressB/XQD Tbt3 Card Reader

Product Build
2-Year Warranty
Pricing and Availability

ThunderBolt 3 Speeds!

The Sonnet SF3 Series CFexpressB/XQD Tbt3 Card Reader is one of very few on the market today that allows maximum datat transfer speeds from CFExpressB. It is the only with dual card slots, dual ports and a 2-year warranty.

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