normally most laptops do not have a very wide range of available processors, having issues with either internal mb/socket form factors/thermal envelope, or inadequate graphics. What few speed grades of cpus might be supported are normally not enough to make a noticeable difference. With brand new quality laptops with SB cpus, 4 gb of RAM, etc., available for $600, a 100-200 MHz increase and corresponding 2% performance increase for $200 does not seem cost effective.