Yes that is normal. I have the HD7950 and it gets the same performance. The r9 280 is just a rebrand of the HD7950. If you are having stuttering issues, lower the water details to medium, and set the v-sync to 1 frame, and also set the buffer to 1 frame for best perfromance. I don't run any anti alising either. You may also have to drop to very high instead of ultra on some settings as well.