1024X768 average Medium to high Settings 25-50fps
Will you notice Hiccups when Tabbing out? Yes Use Overwolf that allows you a Browser, Music player and other apps without Tabbing out.
Overall chips on FM1 are not entirely good for gaming, they will game just at reduced Resolutions and much lower settings. If APU's are of interest to you then FM2 or FM2+ should be the socket and a A6-5400K or better with 1866mhz Ram should be considered.
A4-3400 FM1 $35
A6 5400K FM2 $32 Overclockable better performance
A6 6400K FM2 $44 A setup up over a 5400K
A8 7600 FM2+ $75 Overall a good APU will do Minecraft,LOL, DOTA2 @ 1080p near max settings
Athlon X4 750K $77 + GPU $60+ Better performance than above will cost you much more too.
4GB 1866mhz Ram $37
4GB 2133mhz Ram $44
Motherboards of decent quality
FM1 board $35
FM2 board $40
FM2+ board $68 Asus or Gigabyte A88X