You need to understand that the CPU and GPU frame times depend highly on the scene, the mission and settings (both in DCS and external software/drivers). Be sure to test different maps, missions and settings as these can create totally different results.
If the GPU ends its frame creation it still has to wait for the CPU to display it and vice-versa. Thus best case is when the two match more or less. But it's not possible for all cases. If you see "CPU bound" most of the time it means you can use higher graphic settings without affecting the fps.