On windows movie maker it takes about 30 minutes to upload a 10 minute 1080 60fps video on minecraft..However it takes two hours to render the same 10 minute video on vegas pro? Also I notice that vegas pro's quality is alot better than windows movie maker...(less blotchyness) Does that mean the better the video quality, the more time it will take to render?
Also my system can be the cause of it too
CPU: Intel pentium g3220
GPU; r7 250x 1gb ddr5
ram: 1x4 gb ddr3 1600 mhz
OS: windows 7 64 bit
*also I only edit it by cutting it up for both of the programs*
Short answer: Yes because it is more computationally intensive to produce a better quality video for a given file size. Of course you can always trade off filesize (increase bit rate) for a faster compression while achieving the same quality. Vegas pro probably offers some way of adjusting the compression speed.
BTW neither of these programs are opensource software.