“‘Sire, I believe we should save them for–’ The human said nothing more. The front of his face came free with a sickly crack, the flesh and jagged bone crunching in the Night Lord’s fist. Talos ignored the body as it toppled, spilling the insides of its halved skull onto the decking. No one had even seen him move, such was the prophet’s speed, clearing ten metres and vaulting a console table in the time it took a human heart to beat once.”
The Night Lord (just a standard Space Marine despite being called a "prophet") managed to travel "10 meters and the length of the desk in the time it took a human heart to beat once."
So, we'll assume 15 meters, 10 for the stated distance, 5 for the table. Timeframe is less than 1 second (as the average human heart beats 70 times a minute.) Soldiers are fit and heart beats slower according to this.
So, 15 meters in .9 seconds for the low end.
16.5 Meters per second turns into 36.91 Miles Per Hour. Subsonic Space Marines.