SanDisk 4TB Extreme Portable SSD - Up to 1050MB/s, USB-C, USB 3.2 Gen 2, IP65 Water and Dust Resistance, Updated Firmware - External Solid State Drive - SDSSDE61-4T00-G25

I've owned several of these SanDisk 1TB Extreme Portable SSDs, and the only reason I keep buying more is because I let people borrow them—and they never come back. That’s how much people love using them.What I love:Blazing Fast Speeds: With up to 1050MB/s read and 1000MB/s write speeds, file transfers are lightning quick. Perfect for large media files, backups, or running apps directly from the drive.Compact & Durable: The small form factor makes it ultra-portable, and the IP65 rating means it’s water- and dust-resistant—great for travel or field work.USB-C & USB 3.2 Gen 2: Modern connectivity that works seamlessly with my laptop and other devices.Reliable Firmware: The updated firmware has kept performance consistent and stable across all the units I’ve owned.Bottom line: This drive is fast, rugged, and incredibly convenient. Just be warned—if you lend it out, you might not get it back!

I am absolutely thrilled with the SanDisk 4TB Extreme Portable SSD! This powerhouse of a drive has completely transformed the way I manage my data. The speed is nothing short of phenomenal—transferring large files is a breeze, and I find myself saving so much time compared to my old hard drive.The compact design makes it incredibly easy to carry around, which is perfect for someone always on the go. Plus, the rugged durability ensures that my data is safe, no matter where I take it. I couldn't be happier with my purchase! If you're in need of reliable storage that delivers exceptional performance, look no further than the SanDisk 4TB Extreme Portable SSD.

I picked up the SanDisk 2TB Extreme Portable SSD, and I’m really happy with it. This SSD is super compact, which is perfect for me since I’m always on the go. It fits easily in my bag, and I barely even notice it’s there. I’ve been using it with my MacBook, and it works like a charm. There are no issues with compatibility at all—just plug it in, and it’s good to go. The speed is impressive too. Transferring files is quick, whether I’m backing up large projects or just moving files around. There’s no waiting around, which I really appreciate. Being an SSD, it’s pretty durable. I’ve dropped it once or twice, and it’s held up great. I also love the fact that it’s water and dust-resistant. It’s nice to know I don’t have to baby it. SanDisk is a brand I trust. I’ve used their products for years, and they’ve never let me down. This SSD feels just as solid and reliable as their other products. If you need a fast, portable, and durable SSD for your MacBook, this is a great option. It’s the perfect size, works seamlessly with my Mac, and the performance is exactly what I was looking for.

I got this for my video production class for college because they wanted me to store my edited videos into the 1TB drive. As expensive as it was for a broke college student like me, it was pretty worth it. It portable and really easy to use. Just a simple plug in the computer and it's instantly there. I really like how small it is, only problem with it is that it heats up a little bit fast. If you are thinking about getting this for anything gaming related, DO NOT. It not worth it, you're better buying a better external drive. This drive is for storing stuff like videos and photos or documents.

Product is performing at the level of quality I have come to expect from SanDisk. Despite knowing the specifications prior to purchase, it is surprisingly small and lightweight. Easy to connect. Makes no noise. It has extended my storage capabilities for a number of years. It is worth every penny.

This SSD uses TLC NAND memory, which is a good feature. However, it seems it lacks an internal DRAM cache, which is not very good. I'm not 100% sure tbh about the absence of the DRAM cache, it's difficult to find detailed specs for this drive, but from what I googled, it seems it doesn't have a DRAM cache.The main issue for me—and the reason I deducted one star—is that once the drive is partially filled, the write speed for large files drops to approximately 438 MB/s.When the disk is empty, CrystalDiskMark reports sequential read and write speeds of around 1 GB/s. However, CrystalDiskMark is not a good test for real-world performance, at all (I’ll explain this in more detail below). In actual use, writing large files to an empty disk achieves speeds of about 736 MB/s. As mentioned earlier, the write speed decreases noticeably as the drive fills up. While this behavior is somewhat normal for SSDs, the speed drop can be much less pronounced in more expensive or higher-quality SSDs.That said, reading large files remains consistently fast with this drive, maintaining speeds of around 1 GB/s regardless of how full the disk is.Recently, I realized I didn’t know as much about SSDs as I thought and had been relying too heavily on CrystalDiskMark for testing. Since then, I’ve educated myself on SSDs, learned how to test them properly, and even acquired several different SSDs for testing and experimentation.If you’re interested in learning more about SSDs and proper testing methods, feel free to read on.A lot of people use CrystalDiskMark for testing storage speed. You should know that using CrystalDiskMark is not a good way to test speed. It's a pretty limited test. It can't emulate the real-life use case of copying large files. Even if you choose 64 Gbyte test file size, CrystalDiskMark will simply create a 64Gb test file, but then it will only write or read a small part of that file.So if you want to copy large files with high speed, you need to test it by... no surprise here... by copying large files. Although I think it can be a surprize for a lot of people who rely on CrystalDiskMark. Make sure you will copy from another very fast SSDs, so that the read performance of that other SSD will not be the real bottle neck. I used my fastest internally isntalled NVME SSD to copy large files from (TLC NAND memory, SLC cache, DRAM cache, up to 7 Gbyte/s read & write speeds).Storage drives have different kinds of caches. SSD drives can have an SLC cache (SLC = Single-Level Cell, the fastest and most expensive type of NAND memory) and/or a DRAM cache (for example, an SSD can have 1Gb DDR4 internal cache).Consumer SSDs usually use QLC (Quad-level cell, stores 4 bits per cell, one of the slowest and less reliable types on NAND memory. Used in cheaper SSDs) or TLC (Triple-level cell, stores 3 bits per cell, faster and more reliable than QLC. Used in more expensive SSDs). You can see how an SLC & DRAM caches come into play, for example, here: https://www.techpowerup.com/review/silicon-power-xs70-1-tb/6.htmlMore expensive SSDs also have an internal DRAM cache, which is used before the SLC cache (if present) is used. In 2024-2025 DRAM cache usually uses DDR4 memory. DDR4 cache is a few times faster than TLC for sequential reads & writes and has about a 1000x lower latency than TLC (nanoseconds vs microseconds).So when choosing an SSD, if you want high sustained write-speeds, you need to make sure the drive has the following characteristics (which often can be found in the SSD database on this website: https://www.techpowerup.com/ssd-specs/silicon-power-xs70-1-tb.d707 ):1) TLC type of NAND memory (faster than QLC)2) SLC Cache and the larger, the better (good drives nowadays have 100+ Gbytes of an SLC cache). You can see how an SLC & DRAM caches come into play, for example, here: https://www.techpowerup.com/review/silicon-power-xs70-1-tb/6.html3) DRAM Cache and the larger, the better (1Gb+ DRAM cache is a good size)I'm sorry for this long text, I just hope I can help some people to understand SSDs and how to test them better and make better choices when buying SSDs and SSD adapters.