Do TLC MicroSDs and SSDs need a special tuning for proper alignment?

Question

TLC flash memory has three bits per cell, so block sizes (at various levels) are divisible by three. As a result, when you align the partition just like “use a power of two, 1GiB will be surely enough”, you can easily end up with a wrongly aligned partition, as no power of two is divisible by three.

But aligning for a block size seems to be tricky in general. Well, I might start partition on a position divisible by three. But I can't set an allocation block size to multiple of three on some filesystems (e.g. ext4). Actually, I am not sure that there is any filesystem capable of setting such allocation block size.

Is this solved somehow on today's MicroSD and SSD drives? FWIW, I have both TLC MicroSD and SSD.

By the way, both of them seem to lie the OS about their actual block size. The fdisk shows sector size (logical/physical) 512B/512B.

Answer 1

SSDs that are not aligned will suffer a serious performance degradation - up to 3 times slower than an aligned SSD. You can align a SSD with Windows command prompt. These are the commands:

Diskpart

List disk

Select disk n (where n is the number that was given for your SSD in List disk)

Clean

Create partition primary align=1024

Format fs=ntfs quick

Active (assuming you want to install an OS)

Exit

The Format can also be FS=Fat or FS=Fat32 and 'Active' is optional.

Note that the FAT and FAT32 files systems impose the following restrictions on the number of clusters on a volume:

FAT: Number of clusters <= 65526 FAT32: 65526 < Number of clusters < 4177918

There are also a variety of programs that have an alignment function - e.g. Partition Wizard.

And when you install a Windows7 system or higher, the installer aligns the SSD automatically.

I am not aware of an alignment requirement for MicroSD cards