Luthier is the issue of GPUs not properly engaging their maximum clockspeeds for the game being looked at? It has been reported on AMD HD4xxx, 5xxx and 6xxx series of GPUs. Some Nvidia users as well are reporting that their GPUs sometimes downclock during the game also.
I was able to double my framerate in Cliffs of Dover by forcing the normal clockrate using a third-party overclocking program. However many users will not be comfortable doing this workaround so I would consider it to be a fairly urgent issue.
Please look at this thread:
http://forum.1cpublishing.eu/showthr...t=19807&page=3