Bug ID 475997: SSL stream throughput slows down when hardware SSL offloading is in use

Last Modified: Oct 07, 2023

Affected Product(s):
BIG-IP All(all modules)

Known Affected Versions:
11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,,,, 11.6.4, 11.6.5,,,

Opened: Aug 19, 2014

Severity: 3-Major

Related Article: K16687


When performing LAN-speed transfers of large files (hundreds of MB) over SSL, or transfers of small ssl records, the throughput speed of the transfer significantly drops if the hardware SSL offloading is performed. The performance drop is from ~30% - ~50% depending on the cipher suite used.


The performance degrades from ~30% - ~50% depending on the cipher suite used.


This issue occurs when hardware SSL offloading is turned on.


To work around this issue, you can modify the High-Speed Bridge (HSB) scheduler. To do so, perform the following procedure: Impact of workaround: Performing the following procedure should not have a negative impact on your system. Modifying the scheduler.hsbpollmode.ltm db key Log in to the Traffic Management Shell (tmsh) by typing the following command: tmsh To set the db key value to always, type the following command: modify /sys db scheduler.hsbpollmode.ltm value always Save the changes by typing the following command: save /sys config

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips