Hi, I would like to disable HT from my MacBook Pro Retina running on 10.8 (Mountain Lion) I found some solutions on the Internet but they don't work or not enough for me On 10.7 (Lion) this solution works fine but doesn't on 10.8 OFF: sudo nvram SMT=0 ON: sudo nvram -d SMT The second works on Mountain Lion but it's not permanent. Install Xcode->Open Instrument App->Preferences->Disable Hardware Multi-Threading. It's not permanent unfortunately, after restating the Mac everything returns to normal. The last one (Last Hope ) works but..... sudo nvram boot-args="cpus=4" This solution gave me 4 Cores at Activity Monitor (But I'm not sure if it's 2 Cores + 2 Threads or 4 Cores + 0 Threads) I beleive it's 2 Cores + 2 Threads because I felt the Mac little bit Slow. Now I'm looking for a permanent deactivation of HyperThreading on Mountain Lion. Help Please???? Edit: Why Disable HT From 10.8 ? When I disabled HT with Xcode Instrument, my Mac became tooo fast, all applications started fastly even Apple Video Editing apps like iMove and Final Cut Pro. Why permanent ? For Bootcamp Windows 7. I tried Assassin's Creed 3, works fine on rMBP but when I checked Ubisoft Forums, some users said that HT slow down games, also Ubisoft Recommend to disable HT.