My GF 730GT not work then render out (standard/maincocept mp4). I test Magix Vegas Pro = ok (GF730 NVENC render). I test Ashampo studio4 = rendering GF730 ok
Hardware encoding in MEP (This is not a Vegas forum) is only done with the Intel graphics chipset and the HEVC codec that is free is the playback codec. Not the recording one.
Because Magix have not implemented the use of NVENC in their Movie Edit Pro software. This may be because of some licensing agreement conflict with Intel, or something else. NVENC is enabled in Magix Video Pro X but only for H.265 encoding and timeline preview. Vegas can use it for H.264 and H.265 encoding as you have mentioned.