Sandisk Extreme 64GB - Slower write speeds after system format

This is exactly what the issue is about. Formatting the factory filesystem has absolutely nothing to do with the slowing speeds and I don’t know why it’s being said that causes the problem. I’ve got 2 of these drives and one I formatted to NTFS and the other is still exFAT and both have slowed down in write and reads.

Using SecureErase in PartedMagic has restored it back to normal but surely the flash drive controller should be doing this automatically. I’ve already contacted the retailer I bought it from and requested to return them. You shouldn’t have to manually maintain the drive yourself to keep it working fast. It would have been a great USB drive if it weren’t for this issue.