Compressor vs MPEG Streamclip file sizes

I took an 18 GB ProRes 422 24 minute master and made two H.264 transcodes -- one in Compressor v.3.0.5 and one in MPEG Streamclip v.1.9.1.

Size results:

Compressor: 1.63 GB

MPEG Streamclip: 750 MB

I can understand there would be some variation, but over twice the size in Compressor. Does that mean that Compressor is doing a better job - or perhaps a worse one?

I am also curious that with Compressor running QMaster on all 8 cores of my Mac, it took far longer to transcode than with MPEG Streamclip running normally. Unfortunately I didn't time it.

What's going on?

Lost in space,

Harry.

Harry

Just to be sure you are comparing the same compression parameters try looking at both files with this little utility:

[mediainfo.sourceforge.net]

Check data rate, audio compression, etc.

Vance

Thanks very much. Will try.

Best

Harry.