I'm looking at two laptops. A Dell Precision and an Alienware M14x. Both have the i7 3840QM available. When building the Precision, they list it with a clock speed of 2.8ghz. When building the M14x, they list the 3840QM as "up to 3.8ghz" with turbo boost.
So here's my question, does Intel make multiple 3840QM's... one with turbo boost and one without? Or does Dell just not highlight the clock speed boost when building the Precision for some reason, but not highlight it when building the Alienware? All things being equal, I'd probably go with the Precision, but I want to make sure I'd be getting the clock boost feature with it (even though it's not spelled out on the build).
The specs provided are just a bit inconsistent, but both are correct.
The i7-3840QM's standard clockspeed is 2.8GHz. If Turbo Boost is enabled and the temps are not very high, then the CPU can clock itself up to 3.8GHz if only one core is being used. It will be slightly lower if two core are used and a little slower again if all 4 cores are used. This is basically done to keep the CPU from overheating which means it will under-clock itself (throttling); i.e. run slower than 2.8GHz if the temp is too high.