It is typical for rendering to go to a temp file during the rendering process, then reformatted into the final output file. The temp file is then deleted. Just as you observed. A lot of programs write to temp folders typically without asking. Some of them don't even clean up after themselves.

Vegas lets you pick a folder for temp files. It's in options->preferences:general in the field at the bottom called "Temporary files folder".

There's another configurable folder to watch out for in the File->Properties dialog. It's the "Prerendered files folder".

I see. I have used Vegas 17 Pro before this and that program does not write these huge temporary files, not that I have noticed. I'm editing 4k videos so the file is enormous when done.

Thanks for the help. I will transfer some files to my external drive so C: has enough space.

I see. I have used Vegas 17 Pro before this and that program does not write these huge temporary files, not that I have noticed.

There is no difference whatsoever between versions regarding the rendering of Temp files. It is your output format.

If you want to change the Temp file directory to somewhere on another drive, it's right there on your first page of Preferences:

I see. I have used Vegas 17 Pro before this and that program does not write these huge temporary files, not that I have noticed.

There is no difference between versions regarding the rendering of Temp files whatsoever. It is your output format.

I'm using the exact same settings in the programs. Vegas 17 pro does not write a second file to C:. But Vegas 19 Pro does.

I'm not making things up. I have rendered almost 100 videos in vegas 17 pro and I have never encountered this problem before. Just seems like a step back from earlier versions.

Sure, they may have a back up but not as big as the original rendered file.

I have also been rendering when Vegas was owned by Sony and the program did not write two seperate rendered videos.

This does not happen for example Premiere Pro and other rendering softwares.

If I choose to render to a specific hard drive, I will assume the program will write to that specific place I have choosen.

I am rendering a 4k video that is 8 hours long. The file, when the rendering is done, is 200 gb.

The program, if I do not pick C:, writes two seperate rendered files. One of the files are deleted when rendering is finished. This has never happend to me when using Vegas 17 Pro, never.

As I mentioned above, if I do not change the drive from C:, this will not happen.

@Kristoffer-Holmberg: What build of VP 19 are you using? And what format(s) are you using for rendering out your project?

I'm using build 458.

The format of the original video file is Mp4, H.264.

I'm using the Magix HEVC/AAC MP4 format. I have also tried with Magix AVC/AAC MP4 format with the same result.

I have done some changes to the Template, but only increasing the variable bit rate to

Maximum - 100 000 000

Average - 80 000 000

And also the RC Mode to VBR - high quality.

This is almost the exact same template as I have used in Vegas 17 pro. And I have never stumble upon this before.

This is not a huge problem but knowing that i must always have space on C: is a little bit annoying.

The good news is that this behavior should be altered in the next update. The temporary files for that format should be created in the directory which you have targeted for your final rendered file.