Trim and SSD Performance: Why is it Important?

Recently we’ve received multiple calls about the Trim feature and how it relates to Crucial® SSDs. In a nutshell, Trim is a feature that helps increase the efficiency of your SSD by preparing data blocks for reuse. 

On hard drives and solid state drives, data is stored in blocks. Each data block has data from more than one file, and on a hard drive the blocks can be split whenever necessary. When you delete a file in your operating system, for example, the hard drive deletes only that specific file’s information from the data block, leaving the rest in place. When a file is deleted in the computer’s file system, the data stays on the block until the next time that block is needed. At that point the drive swiftly deletes that particular piece of data from that part of the block, and writes the new file there. Essentially, hard drives are able to delete information from part of a data block – they don’t have to delete the whole thing.

In contrast, SSDs have to delete an entire data block before they’re able to reuse it. When an SSD is trying to clear a data block, it puts a copy of everything on the block into a cache and makes the necessary changes there. The SSD then deletes all of the data on the original block and writes the new data that it was trying to write in the first place.

Understandably, going through all these steps takes a lot longer than it would have taken to simply write data to an empty block. Because the SSD knows this, it simply locates an empty block and writes there. This works great – as long as empty blocks are still available on the drive. When all of the blocks are filled up, the SSD has no choice but to start deleting blocks and reusing them, resulting in a drop in write speeds. This problem, however, can be overcome with Trim – a feature that prompts the SSD to clear previously used data blocks. With Trim, the next time an SSD’s filing system wants to write to those blocks, they are already empty and ready for use.

Dato che non tutti i sistemi operativi supportano Trim, gli SSD Crucial hanno una funzionalità speciale chiamata Active Garbage Collection. L’Active garbage collection (raccolta dati superflui) è un processo che aiuta un'unità SSD a mantenere ottimali le prestazioni, liberando aree della memoria che non sono più utilizzate. La Garbage collection è parte dell’SSD e non è dipendente dal sistema operativo del tuo computer. Dato che la garbage collection è parte del firmware dell’SSD, funziona indipendentemente dal sistema operativo o sistema di archiviazione usato dal tuo computer.

Nota: la garbage collection funziona solo quando il tuo SSD Crucial è inattivo, quindi assicurati di configurare il tuo sistema di modo che non vada in sospensione quando non è in uso. La Gargabe collection impiega del tempo a fare il suo lavoro ma, se ha del tempo per rimanere inattivo ogni tanto, il tuo SSD Crucial manterrà l’alto livello di prestazioni nel tempo.