SanDisk Professional 2TB PRO-G40 SSD - Up to 2700MB/s, Thunderbolt 3 (40Gbps), USB-C (10Gbps), IP68 dust/Water Resistance, External Solid State Drive - SDPS31H-002T-GBCND

Purchase to use with my 2018 15" MacBook Pro, specifically for the Thunderbolt 3 transfer speeds (40Gbps). The drive has worked flawlessly for the past 18 months. I do a lot of astrophotography image processing (stacking hundreds of 60MB images at a time) using this drive, so throughput speed is important for me. The drive design is stylish and rugged, being in a rubberized aluminum case. It is small, light weight and obviously quiet. It was super easy to set up and use, 100% compatible with my MacBook. At 2TB, it provides plenty of capacity for working with my large photo files. This drive is not used for archiving my files, for that I use larger, slower HDDs. Overall this SSD is a great value for the price and I would definitely buy again.

BLUF: I've had quite a few other external drives and this one is by far the best yet. In spite of punishing demands, this one has been a solid performer. This is the model I will return to for repeat purchases.Pros:- It is always plugged directly into a 2025 MacBook Pro with a M4 Max CPU and does not drop (unlike others, including some of SanDisks').- The speed has been impressive and I've not had temperature throttling occur.- The status light is a nice touch (almost all others do not come with one).Cons:- It's a little on the bulky side.- It costs more than others at same capacity.

**** BEWARE *** If I could give this item negative stars I would. I watched a review on solid state drives and this is a $400 piece of junk. From the moment I plugged it in there were problems with this drive. It would freeze up and I couldn't unmount the drive and then it would freeze up my Finder. So then I have to do a hard restart and then I get scolded that I didn't eject it properly. This happens every time I walk away from the computer for more than 10 minutes. All my other external hard drives have no issues going to sleep, but not this one. Then it got so hot I felt like it was going to cause a fire. Even when the drive is not in use, it is burning hot. And now once it gets hot it un-mounts the icon from my desktop and freezes my Finder again. There is something seriously wrong with this drive.So I try contacting SanDisk. They are willing to replace the drive, but I have to send the old one back first. And since I don't have a printer they'll charge me an additional $1 to mail me a label. Why am I paying for something that's not my fault?? And where do I transfer my data to while I'm waiting for the new drive to arrive?? It was already several days late arriving the first time. So I tell them that I don't trust their product anymore and I just want to return it. I'll take my business elsewhere. And the response I got was "once you return the item, we will send you out a new one." Seriously?? What part of RETURN for a REFUND didn't you understand?So I try and do a return on Amazon. But my only choice is to print out a label and return it through the USPS. Except I don't have a printer anymore.So next I contact Amazon customer service by phone and have to deal with that stupid robot which is a colossal waste of time going around in circles who just wants to text me stuff. I don't own a cell phone, and apparently it took an act of God to finally get to a real person. Except I can't hardly understand a word she says in her high squeaky voice. English is obviously not her first language. Then I get conflicting instructions. Kohl's is overrun with returns, so I can take it to Staples. Nope. Scratch that. You have to take it to an Amazon center or a UPS Store. Nope. Scratch that too. So all I'm left with is printing out a label from Amazon, but since I don't have a printer anymore, I can't. I'm so tired of replacing all this stuff because it doesn't work. Why is the answer always to throw more of my money at it? I'm out of money. I am sooooo over spending a fortune on this crap that doesn't work that they expect you to keep replacing. For a $400 drive, I expected a whole lot more.Ultimately I found a friend who said they could print the label for me once they purchase more ink. SanDisk lost my business. I won't be back. I hope it was worth it. And I won't be purchasing anything electronic off of Amazon anymore either. Buyer beware!!

I used this as an external startup disk for an iMac that had become painfully slow due to small ram and large swap file. The memory swapping was slowing it down to an unusable crawl. This fast drive solved that problem completely. The iMac is now super responsive. Highly recommend.

Finally a portable SSD with Thunderbolt speeds! It really is three times faster than the USB 3.2 Gen 2 drive from SanDisk I bought just last year (and, for Mac, also three times faster than USB 3.2 Gen 2x2 drives since the Thunderbolt ports on Mac won't use the second lane at all).At times, plugging it directly into a Thunderbolt 4 port on an M2 Mac mini with the provided cable, it connected using USB 3.1 rather than Thunderbolt. I verified this by looking at the USB and Thunderbolt buses using System Report; also BlackMagic disk speed tests were much slower when this happened (700-800MB/s rather than 2400ish). I'm not sure if that flakiness is caused by the drive, the Mac mini, or the cable—but I'd guess it's the cable. Other times, it connected to the Thunderbolt bus as expected.Mostly I will have this connected to a Thunderbolt 4 hub that nets me two more Thunderbolt 4 ports. I've found that this setup, with otherwise base M2 but upgraded to 24GB RAM, plus the external TB4 ports and storage, is very cost effective for my needs. Note that there is no decrease in speeds having it connected to the hub vs. directly to the Mac.Update 1: Because this SSD (the 4TB version) is **both 50% faster and 15 times larger** than the internal SSD on my 256GB M2 Mac Mini, I have turned it into a bootable drive and am running macOS from it. No complaints! Upgrading the Mac Mini at time of purchase to 2TB (half the space!) internally would have cost a whopping $800 extra with Apple's pricing, and I'd have less space. Not to mention it's impossible to upgrade the internal storage after the fact. Setting up as a bootable drive was simple and painless for me. More benefits of the big, fast bootable drive include plenty of space for memory swapping at higher speeds than the internal SSD if I run out of RAM, plus being able to keep large cloud storage drives fully available offline (Apple's FileProvider forces many of them to live in a particular location on the same volume macOS is installed on, which was too small for them until I moved to this drive).Update 2: If you're looking for a Thunderbolt drive that's a lot faster than this, don't bother looking. Theoretical max data transfer speeds over Thunderbolt 3/4 are limited to something like 22 Gbps (maybe 24 Gbps for Thunderbolt 4?) which translates to 2750MB/sec for Thunderbolt 3. The rest of the 40 Gbps bandwidth of Thunderbolt is reserved for other things. With this drive, I've gotten around 2480MB/sec read and 2400MB/sec write in BlackMagic disk speed benchmarks, which is close enough to top speed that I've stopped looking at, say, external Thunderbolt SSD enclosures + NVMe SSD sticks to try to get faster speeds than this.

It's a great product. I really like it. I’ll have to repurchase it later.