Crucial has begun offering a new firmware update which will add ATA TRIM support to the company’s lineup of M225-branded solid state disks.

The new firmware is stamped with version 1819 and delivers nearly 20 fixes and enhancements, in addition to TRIM. Supported models include:

Crucial M225 64GB (CT64M225)
Crucial M225 128GB (CT128M225)
Crucial M225 256GB (CT256M225)

The outfit also warned users that they may have to juggle firmware in certain circumstances:

Firmware 1711 – Important Notice: If your Crucial M225 Solid-State Drive has firmware 1711 you must first revert back to the 1571 firmware prior to updating to the new 1819 version. Please download the 1571 firmware and follow these instructions.

What is ATA TRIM?

An SSD’s total size is composed of thousands of smaller units called “blocks,” which average about 512k these days. SSDs deliberately try to spread written data across all of these blocks so as not to prematurely wear out the memory chips, which can only accept a limited number of writes. This technique is called wear leveling. Over time, wear leveling guarantees that every block on the SSD will become filled with a hodgepodge of active and deleted data. Once this happens, new writes force the drive to perform an intensive process called the read/erase/modify/write cycle.

An REMW cycle forces an SSD to scan its blocks for deleted files, copy active data to cache, purge the deleted files, append the new data to the data in cache, and then write the cache back to the new free space. This is called write amplification, and in serious cases, it can force an SSD to shuffle up to 20GB of data just to write 1GB of new information. This causes significant performance issues for SSDs.

The solution to this problem is to let SSDs physically erase files the moment they are deleted in the OS, and that is precisely what the TRIM command does. Windows 7 is the only Microsoft OS that supports it, and it must be used with a TRIM-compatible drive.