It may seem silly to spend more than $200 on a single drive when there are several great deals on SSDs on Prime Day. But these two offers are a bit special, offering 4 TB of NVMe storage for as low as $0.05 per GB. That's right, just 5 cents per gigabyte. Amazing.

What I've got here is a great choice between high-capacity but not super-fast and high-capacity and super-fast, and the difference between the two is only $21. So just pick the latter.

The cheaper offer is the Silicon Power UD90 SSD. It is difficult to tell exactly what NAND flash and controller chip is used in this model, as Silicon Power uses a variety of suppliers for components. But whatever is listed under the label, this SSD is not the fastest PCIe 4.0 SSD, and its lack of DRAM means that it will not maintain performance when processing hundreds of GB of files.

However, it is fine for general storage, such as backups, documents, and games, and will serve you well for many years. Just be sure to install it on a motherboard that has a heatsink in the M.2 slot to prevent the drive from getting too hot.

Silicon Power has a full-speed 4 TB SSD, a larger version of the 2 TB XS70 we reviewed last year. It doesn't offer hardware encryption, but it is ridiculously fast and stable thanks to the pre-installed rugged heatsink. It is also suitable for maximum PlayStation 5 storage.

For a gaming PC, it's a near-perfect storage solution, and with Micron's TLC flash memory chips and Phison controller, performance is no issue. It can be used as an expansion drive just to store games, or it is perfectly fine in its role as the sole SSD hosting the operating system, applications, and games.

This large heatsink is very easy to remove and can be attached to any motherboard that comes with an M.2 slot heatsink. Personally, I really like the unobtrusive design and the way it looks with the cooler. [Of the two Silicon Power SSDs, I would choose the XS70. For only $21 more, you get much better performance and probably longer life.

It wasn't that long ago that SSDs were considered big at 1TB. Now you can get one four times that size, large enough to store more than 25 copies of “Baldur's Gate 3”. That's progress for you.