Kernel extension signing prevents drivers from enabling garbage collection on non-Apple SSDs



From V3:

The issue, which has come to light since Yosemite was released, concerns the Kernel Extension (Kext) signing capability that Apple has introduced in OS X Yosemite. This is intended to ensure that low level system drivers are approved and unaltered by malware, by blocking drivers without a valid signature.

However, a knock-on effect of this feature is that it can stop the Trim driver for third-party SSDs from running. This driver is required in order to enable an SSD to effectively perform garbage collection processes and keep the drive performing at an optimal level.

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