Ještě jsem se podíval na minimální požadavky té hry:

Dota 2 Minimum System Requirements:

* OS: Windows® 7 / Vista / Vista64 / XP
* Processor: Pentium 4 3.0GHz
* Memory: 1 GB for XP / 2GB for Vista
* Graphics: DirectX 9 compatible video card with 128 MB, Shader model 2.0. ATI X800, NVidia 6600 or better
* Hard Drive: At least 2.5 GB of free space
* Sound: DirectX 9.0c compatible sound card


http://gpuboss.com/gpus/GeForce-GT-520-vs-GIGABYTE -GeForce-6600-GT-Dual-details#features-body