Dave upgraded his MacBook Pro with a Samsung SSD and it was running TRIM. But OS X Yosemite has a new security requirement called Kext Signing, and it only allows drivers that are approved by Apple. Leo says he can download TRIM Enabler, but he does have to disable kext signing to use it. And that's dangerous because it could open the door for malware. TRIM is built into Yosemite, but it only works with Apple Hardware.