SanDisk Professional 1TB PRO-G40 SSD - Up to 3000MB/s, Thunderbolt 3 (40Gbps), USB-C (10Gbps), IP68 dust/Water Resistance, External Solid State Drive - SDPS31H-001T-GBC1D [exFAT Version]

Minimal packaging. Light and compact. Ready to use on a MacBook. What’s not to love?

This is a very nice build of external hard disk. I use it for file transfer and storage, it is very fast, and with good form factor. It's a bit pricey but I feel it is reliable that's more important. It will become a bit hot when you transfer a lot of files, and that will slow down the speed a little, overall good external hard disk.

I have always used external back-up drives to avoid a disaster with my personal/work computer. My only complaint was how long it took for a complete back-up which sometimes caused me to procrastinate and put off backing up. This SSD with it's Thunderbolt port has completely changed that. The transfer speeds were so fast I went from a nearly two hour transfer process to just over 20 minutes. I basically clone my computer hard drive on the SSD back-up drive and some folders copied so fast I wasn't sure it even copied. I had to go to the directory and make sure the files were actually there. It's not the cheapest option but when it comes to irreplaceable files and the time to transfer them this thing is worth every penny. Plus, at the speeds this thing performs at there is no excuse not to perform regular back-ups to avoid ever losing your files.

Rugged and well built SSD by SanDisk - really does feel like it can take a decent drop. Speeds are quick with the supplied cable! Hard drive did run a little bit hot, but that's not that big of a deal. What is a big deal though is a major issue I ran into. I tested this across two computers and noticed that after the first few transfers and letting the hard drive sit for a little bit - it seemed to idle out and crash the computer when initiating a file transfer, almost like it was leaking memory. The freezing situation starts by me moving a file out of the SSD and in to the computer. It then does not move the file (stays at 0% the whole time while not fully freezing) and gradually slows Windows Explorer until the whole system slows down and comes to a halt. It did this on BOTH computers. Eventually, I found the fix was to force shut down the computer, unplug the SSD, turn the computer back on (wouldn't turn on with the SSD still plugged in), and then I'd initiate the transfer of the file out of the SSD again with no issue. I went ahead and unplugged it as soon as I was done with it. The hardware itself is fine and worked great when it was actually working. Hopefully the flaw above can be resolved with a firmware update! Will update the review if that ever changes!

This first thing to know about the Pro G40 is to discard the included cable and use a true Thunderbolt 4 cable if you are using a Mac M1 or above. The second thing is to ignore the results from other reviewers who didn't use a fast cable to run their tests. See the results I obtained with a TB4 cable and a Mac Mini M2Pro in the included graphic. It actually exceeded the 3000MB/s rating and also properly identified the internal WD-Black SSD that SanDisk is using (lower left corner). Initially I used the included cable as did another reviewer, but those results didn't quite make 1000MB in sequential reads. Something had to be wrong. I don't know why such a feeble cable is included with this very fast drive...but that's the reality. For readers of this review I held my breath and dropped the G40 from waist high first on carpet, then on a floor protector as one uses under an office chair, and finally on a very hard floor. The performance before and after was identical for practical purposes. The accompanying performance chart numbers are the results after the 3 drops. This drive puts my SanDisk Extreme Pro 4TB and Costco SanDisk Extreme Go 2TB in the rear view mirror, each performing at roughly a third of the speed of the G40. And for those of you who are curious, the Costco SanDisk Extreme Go is a slightly slower performer compared to the SanDisk Extreme Pro. I hope this review makes clear how to obtain the best performance of this very fast and rugged portable drive. I tested 5 TB4 cables each under $20 from Amazon and found they all performed identically, so take your pick, it's a good investment. Otherwise it makes no sense to buy this expensive drive. Highly recommended.