Storing a sample library on an external SSD is not only beneficial for saving internal space on your Computer, but can also provide performance improvements as well. This is due to the ability to reference more voices simultaneously than standard hard disk drives.
First things first, SSDs are typically formatted as ExFat whenever they are initially purchased. The reason being is so that the drive can be plugged into either type of operating system and then reformatted so that the drive is then the optimal format for the operating system. ExFat has limitations on the amount of information that can be read and written at a time, which will cause serious performance issues if using a drive formatted to ExFat as a result.
The optimal formats for MacOS is APFS or Mac OS Extended Journaled. For Windows, the optimal format is NTFS.
Instruction on how to reformat an external drive can be found here.
Random Read & Write Speeds
This is the most important factor to take into consideration when purchasing an SSD, as this has to do with the handling of smaller files. This is measured in IOPS and is typically found alongside the sequential read and write speeds in the drive's specs.
In a similar fashion to Sequential Read and Write speeds, a higher speed is better. For example, a drive with a read speed of 10,000 IOPS will outperform a drive with a speed of 6,000 IOPS.
The specific random read and write speeds that need to be looked for are QD1.
For example, the random read and write speeds for the Spitfire SSDs:
RANDOM READ (4KB, QD1)
Up to 10,000 IOPS
RANDOM WRITE (4KB, QD1)
Up to 42,000 IOPS
How This Affects Everything
The random read & write speeds of your drive can greatly affect library performance, and can sometimes be detrimental based on buffer settings. With slower hard drives, this results in disk errors during playback and requires more of the content being loaded into RAM. This can cause an issue when using a machine with a lower amount of RAM installed.
Using an SSD with a higher random and write speed will reduce the reliance on the amount of RAM needed as it will allow for the preload buffer size to be lowered. This essentially allows for more of the sample content to be streamed directly from the drive and saves on the amount of RAM being used.