Prioritising AND bandwidh sharing?

if PCQ is enabled on the routerboard should traffic still be prioritized?
if so then how will a request be handled for eg:

if priorities are set:
1st priority: Port 80
2nd priority: Port 25

client 1 ----------port 25 traffic-------------|
------------ 4mb line speed
client 2 ----------port 80 traffic-------------|

will each client get 2mb speed?
or how will it work?