Chosen Solution
Hi everyone :) Just purchased 27" iMac 2012 without LCD and without Apple HDD (which means no temp sensor in it) iMac is slow - will buying cracked (but WORKING) LCD (I’ll be using in on my 40" TV) fix speed iMac? Do I have to fix HDD sensor too to have “fast” iMac? It is so slow even cursor is barely manage to move :( Thank You for helping me.
There are a number of reasons of why it is slow. The hard drive may be bad or have a low RPM. The iMac also doesn’t see the temperature sensor so it keeps it at a low RPM just in case of HDD overheat. It sounds like you bought this device second hand which means that parts inside it may be broken or some of the RAM may have even been removed/damaged. Hope this helps!
The newer Intel chips support system throttling so the clock of the chip is reduced to prevent the CPU from being damaged from high heat. The newer ‘Thin series’ iMac’s use this signal line. So to answer your question: Yes! Not having the display connected as well as the drive will cause SMC to tell the CPU to throttle.
