Antony, so you did all the things you listed, and then ran the Processor Identification Utility, and it still reported 0.79GHz? I'm sure you did, that is to bad.
The i5-3317U, is a processor from Intel's Ultra segment, meaning Ultra low power usage. This CPU can also be configured into LPM (Low Power Mode), with a driver from Intel. The specified LPM speed of your processor is 800MHz, or 0.80GHz, which is what you are seeing. I cannot be 100% sure your processor is operating in LPM, since the clock speed of your processor can be set manually, for example, but it seems to be LPM.
Intel describes LPM as not a battery power saving feature, but as a means to adjust the processors performance to match a certain situation, and can be changed dynamically, when something special occurs. But, LPM can also be used for scalability, as Intel calls it, which is adjusting the processor to fit more than one usage situation, like a low power use, light weight ultra book, etc.
In your experience, the processor speed does not change when running under a higher load, so it seems to me it has been configured to operate in LPM, because the designers (Samsung) decided that is as fast as it needs to be for its intended use. They can then make the PC's case smaller, and use a smaller fan, so it is quieter.
Does the PC seem slow to you? Does it not perform well?
