JoeyD

Dota 2 is pretty easy to run, you could probably get a RX 480 or GTX 1060 depending on which one is cheaper for you and still be able to play triple A games at 60fps.

750Ti maybe?
I've heard about a GTX 950 that doesn't require power connector but I'm not so sure about it.

this is the only suitable gpu:
https://www.asus.com/au/Graphics-Cards/GTX950-OC-2GD5/
 
this exact model
 

take the side off and get a photo we need to see how much clearance the GPU will have and the motherboard model number if visible
 

Inter Iris Pro graphics is better than 80% dGPU
AMD A-10 APU series is designed with e-sports in mind

there's 750ti and there's also this:
http://www.pcper.com/news/Graphics-Cards/EVGA-Releases-NVIDIA-GeForce-GTX-950-Low-Power-Cards
 
actually if you look closer on the picture of that ASUS card posted above, it actually requires an additional 6-pin connector, so don't use that, get a 750ti or this 950 from EVGA
it will improve performance radically

@TrigrH @apacheprotocol @DXMember Really thank you guys. I'll install AMD driver and use HDMI. Never seen people helping this much for nothing

@TrigrH @apacheprotocol @DXMember Really thank you guys. I'll install AMD driver and use HDMI. Never seen people helping this much for nothing