[KPhotoAlbum] Performance observations

Robert Krawitz rlk at alum.mit.edu
Sun May 13 22:10:41 BST 2018

I stuck about 92 GB (10839 total files, 9997 JPEG, 3 .mov, 839 .cr2)
on my SSD and put kpa to work on it.  My laptop has 32 GB of RAM, so I
should be blowing out physical RAM.

It took just about 6 minutes to load the images.  kpa was getting
pretty good CPU utilization (from one core).  That's 360 seconds, or
255 MB/sec, which is pretty close to the speed of my SSD (around 300
MB/sec).  Unfortunately, I don't have an NVMe drive to play with; that
would be interesting.

It's still building the thumbnails, but that looks like it's taking
about 2x as long.  iostat 5 is showing throughput of about 90 MB/sec.
What's worrisome is that it's showing about 650-700 IO/sec.  So 11000
thumbnails takes about 12 minutes; at that rate, 270,000 images should
have taken in the vicinity of 300 minutes (5 hours) rather than the
11.5 it actually took me yesterday.  This is definitely not up to
snuff; it's at best very I/O-inefficient.

I notice that the say it snapshots videos is to run ffmpeg multiple
times on each file (presumably once for each snapshot frame).  I'd
sure like to find a more efficient way of doing that.
Robert Krawitz                                     <rlk at alum.mit.edu>

***  MIT Engineers   A Proud Tradition   http://mitathletics.com  ***
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