CS6 - Problem editing H.265 and converted H.264 Hero 6 Material

Hey everyone,

I never had any problems working with 4K30 or 1080/120 material using this configuration:

32GB DDR3-1866 DIMM

AMD FX-8350 8x 4.00GHz

750 Watt Inter-Tech Combat Power        

6144MB Gainward GeForce GTX 1060

Gigabyte GA-970A-DS3P AMD 970 So.AM3+ Dual Channel DDR3

2 TD HDD, 500 Gb SSD       

Since I got Hero6 and started shooting in 4k60/1080p240 I was not able to import

any data into CS6. Ok, I use Windows 7 and maybe an upgrade to CC and Windows 10 would be a solution,

but I would like to find a solution working with CS6 and Win7:

I used handbrake to convert H.265 to H.264 and the import worked fine, but

it is ultra laggy and almost impossible to edit the footage in a proper way.

Tried downsizing the footage to 40,20,10 Mbit without any differences.

Maybe my CPU is the problem (it raises up to 80-95% when trying to play converted footage).

Do I need a new computer (I think 8x4,7Ghz is the limit for my mainboard)

or maybe just a new CPU or and ideas how convert H.265 in an other way?