Which CPUs will you find in the Surface Pro 3?

The official spec sheet for the Surface Pro 3 is short on details about the components found inside. I've uncovered details about the exact i3, i5, and i7 CPUs used in the new devices, as well as their support for multiple monitors.

The official spec sheet for the Surface Pro 3, announced earlier this week, says that it will be available with "4th generation Intel Core i3, i5 or i7" processors.

That level of detail might be sufficient for some buyers, but judging by my inbox most ZDNet readers want more details. So I spoke with Microsoft engineers and got the inside story.

Inside the Surface Pro 3, introduced this week in New York by Microsoft's Panos Panay

The Surface Pro 3 is currently available for preorder in a total of five configurations, with three low-power 4th-generation Intel Core (Haswell) CPUs and a mix of memory/storage options. All configurations use solid-state storage and have MicroSD slots for expansion.

The base model, available for pre-order now and shipping in August, has an i3-4020Y processor, running at 1.5 GHz, with Intel HD4200 graphics. This model has only a single configuration, with 4 GB of memory and 64 GB of storage.

First look: Thinner, lighter, more flexible

You've got Surface Pro 3 questions, I've got answers

The model that Microsoft showed off at its press event on May 20 contains an i5-4300U processor, running at a clock speed of 1.9 GHz and Turbo boost up to 2.9 GHz, with HD4400 graphics. (This is the same processor used in the Surface Pro 2.) It's available in two configurations, one with 4GB of memory and 128 GB of storage and the other with 8 GB of memory and 256 GB of storage. Both configurations will ship in the U.S. and Canada on June 20 and will be available worldwide in August.

The top model in the new line has an i7-4650U processor, running at a clock speed of 1.7 GHz with a maximum Turbo frequency of 3.3 GHz and HD5000 graphics. Like all Intel mobile processors in the 15W category, this is a dual-core part. Both configurations include 8GB of memory, with a choice of 256 GB or 512 GB of storage, and will ship worldwide in August.

Like its immediate predecessor, the Surface Pro 3 has a 42 watt-hour battery in a physical package that has been redesigned to fit in the much slimmer body. Microsoft made other changes to shrink the size and weight of the Surface Pro 3 motherboard to roughly half the size of its predecessor. One interesting detail: the motherboard has thin components on one side and thicker components on the other side to reduce its thickness substantially.

For those concerned about multiple monitor support, Microsoft engineers tell me they've tested these scenarios thoroughly. The i3-based model can comfortably drive two Full HD (1920x1200 at 60 Hz) displays, while the i5 and i7 models can power two external displays at a maximum resolution of 2880x1800 each at 60 Hz.

In all cases, you need to make the connection to the external monitors using the mini-DisplayPort adapter on the side of the device. For a single monitor, you can use an adapter to output to HDMI, DVI, or VGA. For dual displays you need either a DisplayPort hub or monitors that support DisplayPort chaining. The docking station (available in mid-August) includes a single mini-DisplayPort adapter and also allows the use of the matching adapter on the device itself, making multi-monitor support easy. In any configuration, you can continue to use the built-in touchscreen in addition to the external displays.