Back End Bound

Back End Bound

TITLE: Back End Bound



This category reflects pipeline slots where no uops are being delivered due to a lack of required resources for accepting more uops in the Backend of the pipeline. Backend describes the portion of the pipeline where the out-of-order scheduler dispatches ready uops into their respective execution units, and once completed these uops get retired according to program order. Examples of issues attributed to the Backend include data-cache misses or stalls due to the divider unit being overloaded.  To calculate this, we apply the remaining slots not attributed to any of the other three categories:

Backend Bound = 1 – (Frontend Bound + Bad Speculation + Retiring)


This metric can be used to determine at a high level if you are bound in the back end of the machine.


For instance, if you had LLC misses, you would see a high back end bound percentage.


Drill down into the lower level back end metrics to find the specific performance issue.



EQUATION:  1 - (Frontend+BadSpeculation+Retiring)

1 post / 0 new
For more complete information about compiler optimizations, see our Optimization Notice.