is it only me?
i purchased a cracked iMac 2015 27 inch 5k on the purpose of learn how to replace the screen and at the same time found out that you can upgrade the 3.5 hard drive to SSD so runs faster.
well not only that
i was able to install a blade apple 256GB SSD and replace the original hard drive with samsung 850 pro SSD 500GB hard drive.
everything runs great! NO need of the thermal sensor cable needed.
i have been using for 3 months no problem, using iMovie and other video softwares. fan runs normal.
i believe saw someone saying that after 2013 iMac you don't need the thermal sensor cable anymore while i was doing research before i started. so i never order one.
after replacing the hard drive. everything runs great !
but here is what i found. using the black magic app i tested the 3 possible update storage methods
1) original apple 3.5 hard drive 1T
2) upgrade 3.5 hard drive to 2.5 SSD hard drive (samsung 850 pro 500 GB)
3) install a thunderbolt enclosure with 2.5 SSD hard drive (samsung 850 pro 500 GB)
4) apple blade SSD hard drive.
here is the result
1 => 100 MB/s
2 => 350-450 MB/s
3 => 300-400 MB/s
4 => 600-700 MB/s
As you can see, there is not much difference between changing the original hard drive to SSD and using an external thunderbolt enclosure with SSD.
so after this i learned that if you are going to update just the internal hard drive. don't bother!! just get an external thunderbolt enclosure with SSD and you still keep your iMac warranty or no need to take the risk of any damage. The internal HD just keep it as extra storage.
If you are going to open the iMac. then you better install a blade SSD that is a high risk high reward.
also for people looking for the Blade SSD
i use the 2013 macbook air SSD works!!!
Oh one more thing! after doing research. only the 27 inch iMac model 2015 5k comes with the PCIe port on the logic board (this i can be sure other i don't know).
on the 21.5 inch iMac, they don't have the PCIe port. so i recommend don't bother to replace the hard drive to SSD, just install a enclosure with SSD instead. you save the trouble.