Are Generic USB Flash Drives Just as Good as the More Expensive Brand Name Drives?
We know flash storage wears out after too many writes. But are vendor claims to be trusted? Researchers at Northeastern University decided to find out. Here’s what they found. Simona Boboila and Peter Desnoyers’ Write Endurance in Flash Drives: Measurements and Analysis (pdf) used chip-level testing, reverse engineering, whole device testing and analytic approaches to test 3 different USB thumb drives to see how they hold up. The problem Flash storage isn’t like disk storage, so flash controllers have to go through some intricate contortions to make it look like a disk. The firmware that does that magic is called the Flash Translation Layer or FTL. USB drives typically use Multi-level cell (MLC) flash that crams 2 or more bits into each cell – at the cost of much lower write specs: 1,000 to 10,000 writes. Generally writing to flash requires that an entire block of flash – 128 KB to 256 KB – be erased and the entire block written again. You may only want to write a 6 KB text file, but t
