if u are comfortable in oc then pick the r9 270 as already said above the 270x has more factory clock speed than the r9 270 so u have the option for ocing the 270 to match up with 270x and the performance difference between then is just about 5% at stock clock speed so its up to u .....are u willing to pay the extra 40 $ or 2500 for 5% difference or not...