arctic silver 5 is probably better out of the two, but i would honestly go online and get a specially made xbox protection thermal paste from XboxExperts. it is in a green tube and has special nanocarbon technology that helps spread out and disperse heat to the heatsink much more efficiently than even arctic silver, which in itself, isnt bad. i have been repairing for about two years. message me with any questions and ill do my best to help anywhere you would need it. and remember, X Clamp fix is not a fix, it is a preventative measure, do not unplug fan and overheat, it oxidizes the solder and bends the board making for possible permanent damage, and always use a pre-heater to avoid warping. if these key things are not followed, your fix will last probably less than a month and will ultimately just put your console in worse condition. also, dont do the penny trick, it just puts extra pressure on the ram chips and can actually crack them, making the work for the people that actually do fix them, alot harder. (;