4/16 - 250 bpm
No this is not impossible; it's what you would call a "blast beat". Just listen to 
 Dark Funeral or any other speedy kinda Black metal or Death metal band. 
And yes, I know how easy this beat is to understand and figure out, it's just a 
 matter of physical endurance and speed that makes this a very hard beat.


  1 e & a 2 e & a 3 e & a 4 e & a

R|o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-|
S|oooooooooooooooooooooooooooooooo|
B|o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-|


And no, this is not a snare roll. The snare is hit with one hand the whole way through. You'll find that it is impossible to play as a snare roll.