Word is going around that some ultrabooks feature a slower version of the NVIDIA GeForce MX150 video card. The new model is underclocked but is not advertised as a different model, so consumers may be getting something something less powerful than expected.
HardOCP reports the difference is quite substantial. The regular version has a device ID of "1D10", while the underclocked "1D12" model has a 36 percent lower base clock. This results in a 20-25 percent performance hit.