The biggest reason why you'll get different responses is because everyone likes different results.
Medium rare steak 130F/54.4C for 2-6 hours
Time will vary according to thickness, cut, age of beast and required texture of result.
Beef fat will start to render at 130F however, much like the collagen to gelatin process for tenderness, it is a process which proceeds slowly at these temperatures. Higher temperatures will render more fat from the matrix more quickly.
Ribeye steak is naturally tender being from a low working muscle group (relatively speaking). As such it contains very little collagen than needs converting to gelatin to make it suitably tender for enjoyment. If you're looking to cook it for fat rendering at 130F you will likely need to cook it for longer than is required for enjoyment of the meat.
So, you need to decide which is more important, the texture and moutfeel of the meat or the rendering of the fat.