WHY the Difference in Driver Version?

[SiHawk]

Recently I upgraded my Drivers for me HD 7850 to the 16.10.1 and on their site they say that the
Driver Version of this is 16.40.2715. BUT in Device Manager I see my Driver Version is now 21.19.151.3!
I wrote AMD Tech Support but have not heard back....don't think I will. Does anyone here know why this
anomaly?
[Recent History: I have one of the no longer supported integrated CPU/GPU's - the A10 5800K, w HD7660D on board + I added a discrete Card - HD 7850. When I unknowingly upgraded to Driver 16.9.2 Device Manager told me NO Driver installed for the on board GPU, but Driver V. 21.19.137.1 were installed for the Discrete Card........I started getting a lot of CTD's........contacted their Tech Support and was told I would have to go back to 2015 Drivers to enable support for BOTH GPUs! Other choice: Disable/remove the on board HD 7660D GPU from the picture.....then the 16.10.2 Drivers would work w/o problems for the HD 7850. That is what I did......my Device Manager now only displays my standalone G. Card.....but with thi unkown D. Version????]

THANKS

 

[Elixer]

You have a legacy device, that isn't updated much, if at all, so that is why you need the older drivers if you are still using it.
However, since you got a dedicated card, you are better off using that, which has newer drivers.

 

[SiHawk]

You have a legacy device, that isn't updated much, if at all, so that is why you need the older drivers if you are still using it.
However, since you got a dedicated card, you are better off using that, which has newer drivers.

That is what I am doing - using just my discrete Video Card, thought I explained that inn my question....wondering WHY the ODD Driver Version # is associated with updated drivers for my HD 7850 Card?