microSD UHS-II Dual-Slot Memory Card Reader by ProGrade Digital | USB 3.2 Gen 2 for Professional Filmmakers, Photographers & Content Creators

I purchased the dual MicroSD card version to try and cut the time it takes me to transfer video from two GoPro cameras I use to record my motorcycle riding days. When I go on multi-day tours, it would take significant time to transfer video at the end of each day when I reach my destination hotel.To determine value of spending not inconsiderable amount on money on this gadget, I tested its performance immediately on arrival (30 minutes ago) and here is what I found.Transferring video from a single MicroSD card (SanDisk Extreme 256GB A2) average transfer speed to a MBPro (late 2016) onto the on-board SSD was 54MB/sec. This represents 3 times transfer speed compared to low cost card reader I used to date.This result in good. Not great. I expected it to get closer to advertised 100MB/sec to 120MB/sec which would make it great. 3x faster transfer is good, even very good but short of great.Second test was transferring from 2 MicroSD cards at the same time. I used identical MicroSD cards (again, SanDisk Extreme 256GB A2), each with 30GB of GoPro video.THIS IS WHERE THIS CARD READER SHOWED WHY IT COSTS SO MUCH.Average transfer speed was 61.9MB/sec for the first transfer and 62MB/sec for the second transfer.Why the individual speed of dual transfer is higher than speed of a single transfer I cannot tell but this result moved it from good to very good, to great.I am looking forward to 2021 touring season where I expect to be able to reduce my video copying time from 8 hours each night to 1 hour 30 minutes (512GB transfer at 55MB/sec vs 17MB/sec).

I purchased this item because it's supposed to be the best / fastest micro SD card reader out there and it would only read my Sandisk Extreme cards at 90MB/s. Now it will do both at 90MB/s simultaneously, which is cool, but I can also plug my cards into a CalDigit reader and it'll more or less max out at 150MB/s there, so it seems ProGrade throttles Sandisk cards or lies about how fast they read. On top of that, after about 4 months it just stopped working completely. I called ProGrade and they were happy to replace it and did. That new one worked the same for about 4 months and died again today. My conclusion? Junk.

love how easy it is to use

The product is very well built.The magnet can be very useful and works well.The speeds on this are not the best.Using the B09X7CRKRZ and B09X7MPX8L (SanDisk 512GB or 1TB Extreme microSDXC UHS-I Memory Card) as test subjects with both this reader and the B07G5JV2B5 (SanDisk MobileMate USB 3.0 microSD Card Reader- SDDR-B531-GN6NN) card reader.The Scandisk came back with ~130MB/s writes and ~175MB/s reads with a 4GB file.This unit managed ~90MB/s writes and ~112MB/s reads with a 4GB file.This was done on a USB3.1 Gen2 port and a ESATA drive (transferring between drives was upwards of 700MB/s speeds for the same 4GB file.)The device does not stand up to the speed tests but is reliable and recognized by devices quickly. It hasn't had any problems reading various Micro SD cards.If you need the fastest thing look elsewhere but if you just need something sturdy and reliable this is a good device. There are also cheaper solutions on the market.

I purchased this directly from ProGrade. Ironically, i was previously using the Lexar card reader which used USB 3.0 speeds for the CF card, but it did not apply to the micro sd port. My computer uses USB 3.0 Gen 2 as well, so i was sure it was the reader.I haven't tested two cards simultaneously yet. This reader does its job well has maxed out the read speed of the micro sd cards i've tested. A surprising bonus is the magnetic body. At first i considered it a gimmick, but it's actually pretty convenient to mount on top my Mac Pro.The only complaint i could find is that the face of where you insert the cards is a glossy reflective material and scratches easily. Purely aesthetic though. Also that the cable supplied is a aimed at laptop use and is a little short for desktop use.Overall this should be a good investment for quite a while until micro sd card speeds surpass USB 3.0 Gen 2.

Update August 31 2023: One of the ports no longer works after using it about 10 times. Manufacturer does not answer calls and voicemails are not answered.Original review: Works good and does not slow down when copying from both slots at the same time. I tested it in Windows 10 Pro.

it is very disappointing to find out the card reader actually shares the speed between 2 slots...it doesnt read max speed from each card..for example if u read 1 card it will download 60mb/s, and if 2 card it cuts it in half...30mb/s

Broke in 3 months-just stopped working, sent back. Piece of crap, don't buy, waste of money and time.