Hello, it’s me again. I read a lot about how unreliable micro SD cards are if you use your RPi to selfhost some stuff. Now I wanted to ask if some of you might have recommendations for cheap but reliable external SSDs. I did some research on Amazon but there are some brands I never heard before (Intenso, SSK, Netac, etc.) and don’t know if they can be trusted.
Most enterprise drives are TLC these days, MLC just doesn’t provide the storage density that enterprises require anymore. I only mentioned MLC because you’ll occasionally find mSATA drives in the <=256GB range that use MLC. You have to check the datasheet for each model, look for endurance rated at 5DWPD or higher, those will typically be MLC or heavily over provisioned TLC. If you want enterprise drives with greater endurance than the usual 0.5 or 1 DWPD look for the over provisioned models with capacities like 400GB, 800GB, 1.6T or 3.2T. those are 512GB, 1TB, 2TB and 4TB raw capacity drives with a bunch of flash set aside for wear leveling purposes. You don’t often see 300GB, 600GB, 1.2T or 2.4T drives anymore but those are often very high endurance (write intensive, 10 DWPD or so) models.
Check the datasheets for drives when you’re shopping and you can get a pretty good idea of what their durability is like, I usually buy 1 DWPD drives for write occasional bulk storage and 3+ DWPD for anything with a serious write workload. You can also help the drive controller a bit by running blkdiscard against the entire device before partitioning, then only partition and use ~80% of available space. The drive controller will typically grab free unused blocks and use them for wear leveling but only if they’ve been marked free (TRIMmed) and never allocated after. If you can’t find or can’t afford high endurance drives you can usually buy a larger lower endurance drive and over provision it in this way to extend its lifespan.
(The last time MLC flash was really common was back in maybe 2014-2015, some of the older Samsung pro drives like the 850/860 pro were built using MLC. Those had legendary real world endurance, I think they’d get up to 10+PB written before actually failing. It’s a shame they didn’t have PLP because they would have made good budget array storage if they did.)