One of the longstanding differences between OS X and Windows 10 has been the degree of support for the solid-state drive TRIM command. TRIM is a method of performing garbage collection in SSDs, it's been part of Windows since the release of Windows 7, but Apple has historically only supported TRIM on its own OEM drives. This issue became more pronounced last year, when the company forced users to disable driver signing and other OS security features if they wanted to use third-party applications to enable TRIM. Now, that problem should be rectified -- the latest version of OS X El Capitan, OS X 10.10.4, includes support for TRIM on non-Apple hardware.
TRIM, for those of you who aren't aware, is a garbage-collection method that allows the operating system to inform the SSD which blocks of data are no longer in use and can be wiped. SSDs also perform their own internal garbage collection, but the TRIM command allows the drive to avoid write amplification by not re-writing data that's actually been cleared for deletion. Combined, garbage collection and TRIM are two methods for improving overall drive performance while minimizing wear-and-tear.
According to Ars Technica,(Opens in a new window) TRIM can now be enabled via a simple command-line executable, dubbed "trimforce." Running it earns you a giant scary wall-of-text, but the activation is simple and the site observed no problems thereafter:
Image courtesy of Ars Technica
Samsung and Crucial SSD owners should be aware, however, that trimforce doesn't support all SSDs and that some models appear to perform poorly or are vulnerable to data corruption. A lengthy report from Algolia(Opens in a new window), a search API company, indicates that there are significant problems with how certain Samsung and Crucial drives handle the command. Some have said that the issue is confined to queued TRIM, but Algolia disputes this, noting that they observed the problem using both queued and unqueued TRIM.
Samsung, apparently, has previously refused to diagnose or examine the problem, since it's only an issue under Linux. The company prioritizes drive support for Windows, which makes sense, since that's the overwhelming majority of the market, but may have left users who want to use Samsung's high-end 850 Pro and a non-Microsoft OS out in the cold. The Algolia blog post steps through the problems the company detected and notes that Samsung is now investigating these issues itself.
If you don't have a Crucial or Samsung SSD, rejoice! Better SSD performance on Apple hardware is now yours for the taking.
