Depends, I'm not quite sure what you are talking about.
You mean when you are getting hit? Highly unlikely, the person who is nailing you is doing the damage computation on his FE and is sending you the information of what's damaged for your FE to break off.
Only way you could suffer a FR slowdown would be from wav file overload (the wav file for the hit sounds is >200kb and is played 5000 times in a second), or.. actually I'm pretty sure that's the only way.
If you mean on your FE when you are dealing the damage, it's entirely possible using a highly detailed damage model that has to do a lot of calculations/second to compute the damage being done. Good example of this is in FB using the Hurri MkIIb, it has 12 .303 MGs which have a very high ROF. This leads to a LOT of calculations for (supposedly) each round and how it's effecting the plane it's hitting.
I get terrible slow downs when using the Hurri IIbs to attack He111s.
-SW