When reading from a flash device the device can only read whole blocks at a time right? And 1 block of that drive is probably like 1MB, right?
No, you only have to read 512 bytes at a time (or on new sata drives it's 4k).
addbuffers gives more buffers to the filesystem, if that buffering is fast then adding it to the device as well is not worth it.
FFS gets slower if you add a lot of buffers & someone did do some device patching software that allowed you put buffering at the device layer.
My understanding is that SFS/PFS don't suffer from this.
