i have a newly built pc it has a intel i5 3470 CPU, gigabyte ga-z68p-ds3 Motherboard, AMD rtx 570 sapphire 8gb GPU with 1 ddr3 stick of 4gb g.skill sniper and 2 ddr3 2gb sticks of Samsung ram. i have a tp link wn781nd WiFi card and it is running at under 10% of its capacity but my download speeds are horrendous. at its peak i am getting maybe 250kb per second and that lasts for about 10 seconds then goes back down to about 150kb per second. what can i do to speed this up?