Yes, the speeds of the two processors you mentioned are correct, although they both have turbo boost, the i5-470Um to 1.86GHz, and the i5-520M to 2.93GHz. Intel currently has 20 Core i5 Mobile processors on the market, the "UM" versions having a different application than the "M" versions. The UM CPUs are intended for small, low power usage tablet PCs. These are all the Intel Core i5 Mobile Processors:
What type of PC is the i5-520M used in? A standard laptop or a tablet? The EP121 is a Tablet PC, a smaller, lighter, and more portable than a laptop. Tablets simply will be a less powerful PC than a good laptop, just as a good laptop is less powerful than a good desktop PC. The i5-470UM CPU has a maximum TDP of 18 Watts, that is incredible for it's performance, the i5-520M's maximum TDP is 35 Watts, and could not be used in a tablet PC. Comments I read about the EP121 said it is "... almost a laptop...", which is a great compliment for a device of this type and size.