SanDisk Cuts ExtremeFit 512GB USB-C Drive to $99 in Prime Day 2026

Q: This coin-sized drive promises convenience, but do its hidden performance flaws make it a frustrating purchase for its intended users?

For most of its target buyers, no—the SanDisk ExtremeFit’s weaknesses are real, but they are unlikely to make it a bad purchase unless you expect SSD-like sustained performance. The main hidden drawback is write speed under heavy use. While the drive can hit its advertised read speed of up to 400 MB/s, independent testing shows write speeds can fall from roughly 130-189 MB/s to around 80-100 MB/s during long, continuous transfers, likely because of heat and limited cache. That makes it a poor fit for users regularly moving very large files, shooting constant 4K footage, or doing sustained backup jobs. But that limitation matters less for the audience this product is actually aimed at. As a tiny, plug-and-stay storage expansion device for laptops, tablets, and phones, it is better suited to occasional file transfers, media storage, document libraries, photo offloads, and light editing. In those uses, reviews suggest the slowdown is noticeable but not deal-breaking. There are also practical trade-offs beyond speed. Its ultra-small body makes it easy to lose, and despite the compact design, it may protrude enough to snag or block a neighboring port on some devices. Buyers are also paying a premium for size rather than raw performance. At $99 for 512GB, the Prime Day deal is decent rather than exceptional. Users who value minimal bulk and broad USB-C compatibility will likely be satisfied. Buyers who need consistently fast writes should skip it and choose an external SSD instead.

3 articles · Updated · ZDNet · Jun 24

$99 buys SanDisk's 512GB ExtremeFit USB-C flash drive during Amazon Prime Day, trimming $20 from its usual $119 price through June 26.
The coin-sized drive targets buyers who want extra laptop storage without a bulky SSD, offering plug-and-play setup and read speeds of up to 400 MB/s.
SanDisk sells the ExtremeFit line in capacities from 128GB to 1TB, but the discounted 512GB model is positioned as the most practical balance of space and price.
ZDNET rated the offer 3 out of 5, saying the 17% discount is solid but would look stronger if the price fell below $99.