Video recording
1536 MB for 600 seconds = 2.56 MByte/s = 20 MBit/s avg bitrate.
This is normal for a 4k MP4, even a bit low already (moderate MP4 quality at 4K is reached with 30Mbit/s+ avg bitrate).
To keep quality while shrinking size you could render in 1080p (which would quarter the pixel count per frame) with 5 MBit/s (reduction factor 4 vs. 4K because resolution is quartered) As you said above, you want to upload it in 1080p on Youtube anyway.
1080p@5 Mbit/s would yield a size of 375 MB for 10 Minutes (at the same compression parameters you used for 4K). Youtube seems to downsample the 4K content anyway for the 1080p mode, so you can save bandwidth by doing that locally already.
(edited by Ettanin.8271)
1,5 Gb for 10 minutes is great actually.
I am already used to fraps 1~2gb per minute.
A couple of ways to lower the file size:
1) Record at a lower framerate (25 FPS is actually fine, if you have that option).
2) After you are done recording, re-render it with a video editing program and use the Xvid or DivX codec for the compression. You should be able to find a good balance between file size and quality, but you may need to experiment a bit with the codec settings. I’ve was able to achieve a file size about 15 times smaller back when I was recording WoW videos.