This is an extended alternate picking exercise given to a guitar student. The original was basically finished on beat 3 of bar 2 shown in this video. The extended version gives some more fingering variety, and is good for endurance work.
For pure speed work, I recommend breaking this up into smaller pieces. Breaking it up into smaller pieces is something I did in order to work this thing up to a speed I wanted, and you can see the steps I took in the Guitar Log on the YouTube channel.
Here is the Guitar Pro 6 tab for this lesson:
John Taylor - guitar and bass instructor for Mile High Shred.