Would SSD drives benefit from a non-default allocation unit size

formathard drivessd

The default allocation unit size recommended when formatting a drive in our current set-up is 4096 bytes. I understand the basics of the pros and cons of larger and smaller sizes (performance boost vs. space preservation) but it seems the benefits of a solid state drive (seek times massively lower than hard disks) may create a situation where a much smaller allocation size is not detrimental.

Were this the case it would at least partially help to overcome the disadvantage of SSD (massively higher prices per GB).

Is there a way to determine the 'cost' of smaller allocation sizes specifically related to seek times? Or are there any studies or articles recommending a change from the default based on this newer tech?

(Assume the most average scattering of sizes program files, OS files, data, mp3s, text files, etc.)

Best Answer

If you are looking for an good article I recommend

The Hows and Whys of SSDs by Robert Hallock

I linked to page 2, which contains the part which discusses clustering and block size.

[...] The solution to the problem is to increase the cluster size, for which there are several advantages:

  • Reduced file system complexity; less clusters means less to organize.
  • Increased read and write speed as cluster size approaches parity with block size.
  • Decreased slack space if the system is primarily composed of large files.

Yet increased cluster size is not a magic bullet for solid state disks, as most people have a mix of information. Games often contain a myriad of small files and operating systems are the sum of small files almost as a rule; yet movies, music, archives and MMOs are perfect candidates for enlarged cluster sizes. More frustrating than the anchor of small clusters is the complicated process to get larger clusters under modern Windows operating systems. Such a feat requires premeditated use of programs like Acronis Disk Director which can increase cluster sizes prior to the installation of Windows. It is also possible to resize existing clusters, but such a procedure is accomplished with a frighteningly varied degree of success.