I have probably identical to your set up or what you're wondering, and ultra is too high. It chops in a lot of instances, but on high it runs well. 3v3s or 4v4s will still chop at high though. 1v1 or 2v2 will be fine at high, not ultra. 1gb of vram is recommended for ultra textures, 512mb for high. Hope this helps, cya in game maybe.
Also check this;
AnandTech - Bench - CPU