We’ve seen photos and video of the prototype Nokia RM-626, but it was hard to determine the actual size of the display without a solid comparison. Thanks to Techno Buffalo’s latest video, they confirmed it has a 4-inch capacitive multi-touch display.

We don’t know the commercial name for this prototype yet, but my guess is Nokia N8-01. Others say N9, C7, etc, but right now, there’s no official confirmation.

The video is embedded below. Head to the blog if it’s not visible in your RSS reader.

Some other things that are worth mentioning are the 640×360 resolution, front-facing camera with LED flash (is that world’s first?), and HDMI out.

Nokia RM-626 next to iPhone 4 and HTC EVO 4G

I’m concerned that the resolution isn’t good enough for a display this size. Keep in mind the Apple iPhone 4 with a 3.5-inch screen has a 960×640 resolution while a Samsung Galaxy S with 4-inch screen has 800×480. Without even holding the actual device, I can tell you right now that the display on this prototype RM-626 isn’t sharp.