it works fine, i played at least 15 minutes and it didnt crash. 900 and 1030, should it try 910 or else ?
Leave it at 900 for a while and see where you are at. You can try 910, but OCing is like babysitting a 7 year old with ADHD. You have to keep watching it and even though everything seems fine for a while, it could spaz out anytime. 900 is a nice round number. You can probably get 1050 or more on the memory. I like round numbers to work with, OCD kicks in.
Try OCCT's GPU stress test for an hour, turn on error checking to. 900/1050 seems like a solid OC.