@tech007 

Looks like this information isn't available on the Internet yet.

However, given the pricing of the A6 (and its sister model C6) my guess is that V4 still uses a MediaTek chipset, just a newer one. Potentially TP-Link might have switched the A6/C6 to the same chipset they already use in router's like the C64 and C80.

These lower-end routers usually don't draw a lot of power during normal operation. Probably less than 5 W.

You can check www<dot>tpcdb>dot>com/list.php?type=11 to get an idea. 

So, in best case you might be able to save another Watt by selecting a certain router version, which will save you maybe 1 KWh per month.