I had the same issue with the ASUS ROG 702V. You need to turn off Secure Boot and then you will see the option to change the setting to enable the use of the 600p. I haven't tried turning Secure Boot back on but haven't bothered with it.
P.S. Loving the 600p - great, amazingly fast drive for a great price
After checking all the specs of your system we can determine that this one is fully compatible and it should work fine with your SSD.
One recommendation we always provide is to have the latest BIOS installed.
The suggestion Abantech provided is correct, you may want to double check your BIOS settings and disable the option that shows as "Fast Boot", we have seen cases where this feature needs to be disabled so it can be detected.
Please let us know if it works for you.
We are following up the thread and we'd like to know if you require further assistance.
We'll be waiting for your response.
I also had a problem with my 600p SSD on my laptop. I've tried a bunch of solutions previously mentioned on different forums all over the net (EaseUS Todo Backup Free, AOMEI Backupper and other).
What finally worked for me EaseUS Partition Master 11.9 http://download.easeus.com/trial/epm_trial.exe ,
I got a license key from Humble Software Bundle for PC Lovers (pay what you want and help charity) it only cost around 6$ (bundled with additional software, awesome bundle especially since it came with other programs like System Mechanic 16.5 which optimized my system before the actual OS migration).
In EaseUS Partition Master 11.9 I started the option Migrate OS to SSD, it automatically detected the 600p SSD and did all of the following steps on its own. I just clicked restart when it asked to restart, and from there the migration continued. I went to sleep and in the morning the computer was waiting for me with all of the files migrated to the SSD and even didn't had to change the boot priority in the BIOS since the EaseUS Partition Master did that already.
Now I'm enjoying the blistering speeds of the Boot-able SSD and my 1 TB HDD is now my storage drive.
Hope this will help you too.