The Surface Pro 3's internal construction is both innovative and an industry first, in particular the custom-designed power and cooling systems. But on the other hand, it is of course an evolution of the original Surface Pro design, reinvented for a much thinner form factor. So what's it like in the real world?

Not bad, actually.

Like previous Surface Pro devices, Surface Pro 3 provides both active and passive cooling technologies.

On the active side, there is a very large but flat custom-designed fan, with curved, symmetrical blades that keep noise to a minimum. This one is brand new to Surface Pro 3, and has been "reinvented" for this device, according to Microsoft. Furthermore, it is supposedly "30 percent more efficient than the fan in any product to date," whatever that means.

On the passive side, there is the same perimeter vent all around the device's edges as we saw on Surface Pro and Pro 2. And the interior of Surface Pro 3 was designed such that warm (or hot) air is supposed to flow naturally to all edges, and not concentrate in one or two places, as is common with laptops and Ultrabooks. This system works whether the fan is running or not.

Surface Pro 3 internals

At the Surface Pro 3 event last week, Panos Panay said that one wouldn't feel, hear or see the fan, or the heat coming off the device. In use, however, I've noticed that the top of the right side of the device (looking at it in normal landscape mode, around the USB and mini-DisplayPort ports) gets warm first, while the rest of the device is cool. Once the fan fires up, heat does indeed seem to be dispensed pretty evenly. And you can hear it clearly when it does come on.

Fortunately, that doesn't happen too often. For much of the time, Surface Pro 3 runs coolly and without untoward fan noise. But it's still a PC. And that means that certain activities, many of which don't seem to be directly related to anything the user is doing, cause the fan to fire up. And the low humming hiss that emanates from the Surface Pro 3 fan, while not overly loud, is still noticeable and not what one expects or wants from a tablet. And, yes, the device does get a bit hot around the edges from time to time as well.

Disaster? Hardly. But it's worth noting.

If you're familiar with modern portable computing devices, you won't be surprised to discover that playing back an HD video doesn't ever make the fan fire up. Gaming, however, can, including some fairly innocuous looking casual Modern games. I had sort of hoped—expected, even—that the new Modern mobile apps, written for a platform that is designed to be as energy efficient as possible, would be somewhat immune to the age-old PC concerns like fans and heat. But that doesn't appear to be the case.

Long story short, this is an amazing thin and light device and given the fact that full-powered Intel Core i3, i5 and i7 processors—i5 in my review unit—require a fan for adequate cooling, Surface Pro 3 is pretty impressive in this regard. But it's not like a fan-less device: If you push it, it will get warm and that fan will kick in.

This is something I'll keep my eye on as I work towards my eventual review. But so far, Surface Pro 3 delivers the power and cooling one might expect of the average Ultrabook, not the average tablet. And really, that's to be expected.