08/27/2011, 04:53 AM
I want to clear something up, I've been reading a couple of times.
Just because the "original" Touchpad runs at 1.2 GHz and the new white one runs at 1.5 GHz does not necessarily mean it was underclocked!
The chip in the Touchpad is/was brand new. So new, it was not publicly announced prior to the "think beyond" event.
Now, some basic things about processors: not two are the same! The manufacturers offer different models at different speeds for a reason: some chips have defects (parts are disabled => less cache for instance) or can't run stable at higher clocks.
Why is it important that the chip was brand new? Well, of course Qualcomm can "guess" the clockspeeds based on their design, the information they have from the manufacturer and evaluation samples. The chip inside the Touchpad is probably not made by Qualcomm, but by foundries like TSMC or others. If the chip is brand new the manufacturing is not perfect and design mistakes can result in lower yield.
Now, Qualcomm probably binned hard to find the 1 in 100 chips that runs 1.5 GHz, just to show "hey, we can do it!". But HP would have had to pay for that binning through the costs of the chips. As production ramps up Qualcomm can randomly pick some chips and bin them. When they see the quality of the chips go up they can bin more easily, the price of the 1.5 GHz SoC decreases.
In fact, as the demand for the cheaper chips is higher very often chips are binned lower than what they are capable of. That is the reason why many Touchpads can run 1.5 GHz without an issue. But that may not be the case for everyone.
Now, you probably think back to the original Pre, where the chip was running at 500 instead of 600 MHz. Indeed, there the chip was underclocked to improve the horrendous battery life of the Pre. We know that for a fact because there is no 500 MHz model of the Pre's SoC. For the Touchpad's SoC however, there are 1.2 and 1.5 GHz models available. Consequently, the chips are binned for 1.2 GHz, not underclocked!
Just something I thought should be mentioned. Note that I don't work in this industry, I just have some knowledge about it. So, if you think I'm wrong, feel free to share your thoughts