Nvidia claimed its numbers for the K1 are on par with the Apple A7, but experts remained skeptical. If you, too, had some doubts about the power efficiency of the Tegra K1, these latest revelations would only further fuel them. SemiAccurate looked back at earlier demonstrations of the new chipset and spotted some interesting details from Nvidia’s CES demo. Namely, the fact that the gigantic system demoed at CES is not just large in size, but also - actively cooled.
This disturbing fact alone is enough of a red flag, but SemiAccurate also gleaned at the power brick for the Tegra K1 demo box, and it reveals a truly shocking power draw. With a voltage of 12 volts and 5 amps of electric current, we arrive at a total peak power draw of 60 watts for the entire demo box! Truth be told, the actual power draw of the system is not likely to reach that peak - it was probably running at around 35 watts to 40 watts, according to SemiAccurate’s rough estimates. This is the power draw for the whole system, including all other on-board components (and the fan), but the Tegra K1 is obviously one component drawing a sizable amount of that power. It’s also no coincidence that it’s the only component with a heatsink on it.
This huge power consumption of the Tegra K1 is definitely shocking - after all, we have seen the perfectly regularly sized, 7-inch Nvidia Tegra K1 reference tablets running without any huge overheating issues, so we know that at least that is possible. We don't know whether there were any differences between the clock speeds of the Tegra K1 developer box examined by SemiAccurate and the K1 reference tablets, but still, with all this new information, we’d take a slightly more conservative stand on the Tegra K1.