A little performance review of the new Acer CB3.
I want to say up top that this is mainly about the Bay Trail n2830 chip, since we're seeing it in so many Chromebooks. I don't think I'll write up my thoughts on the casing, screen, and stuff like that of the Acer CB3 itself, but feel free to ask about them and I'll answer as best I can.

I made a video for some of these tests, so why not watch and read on: Samsung Chromebook 2 vs Acer CB3

The two Chromebooks I used in this test are the Samsung Chromebook 2, 11" version with 4GB of memory, and the new Acer CB3 with 2GB of memory. Both are on the latest Stable channel. The Bay Trail n2830 found in the Acer CB3 should hopefully be fully representative of other Bay Trail n2830 powered models, though you may have a different experience when paired with more memory or a higher screen resolution. The Samsung 2, 11" is the slowest of the new generation of ARM powered Chromebooks, where the 13" Samsung 2 is clocked faster, and Chromebooks with the ARM based Nvidia Tegra K1 should also be faster. So, if we see the Samsung 2, 11" perform better in a particular test here, then it's practically guaranteed that Tegra K1 powered Chromebooks will also perform better than a Bay Trail n2830 model.

There are already benchmarks for the Bay Trail n2830 out there, so I haven't added them here. Instead, I wanted a more "real world" test of a few tasks that aren't hard to measure.

Start up Time
The Bay Trail boots up faster. Simple enough. It's definitely within a second difference in time, though.

Loading a single webpage
The Bay Trail also does this faster, but the gap is extremely slim. The results of a benchmark like Sunspider would have made me guess the gap was larger.

Loading up seven webpages at once
Some people like Chrome OS to open on several webpages right when they turn it on, or ask it to resume the pages they last had open before they turned it off. This is meant to test that out. I'm not informed on how Chrome OS handles webpages you have or haven't visited already, so for this test I let both computers load up each page, exited all browser windows, then opened the pages all at once again:
The Samsung 2 handles this faster, which shouldn't be a surprise because it has twice as many CPU cores running at once. The difference was about 4~5 seconds faster.
For reference, it took about 25.5 seconds on the Samsung 2, 11" opening the following pages: Engadget, Google+, OMG!Chrome, Gmail (webpage), Spotify web app, YouTube home page, and the Chrome Web Store.

720p Youtube video
For this test I paused the same video on each machine as soon as possible, then set the video quality to 720p and opened up the "Stats for nerds" info box, so I could see dropped frames over time.
Over the course of three and a half minutes (or 6300 frames) the Samsung 2 dropped 0 frames, while the Acer CB3 dropped 44 frames.
What does this mean? Well over the course of three and a half minutes it's hard to notice a frame missing every once in a while, but it can stutter during scenes with lots of movement. They're both essentially smooth.

1080p YouTube video
Most Chromebooks are equipped with very near 720p screens, but one upcoming model will have a variant with a 1080p screen paired with the Bay Trail n2830 the similar but faster Bay Trail n2840; the Toshiba Chromebook 2.
The set up was the same as the 720p video test.
Over the course of three and a half minutes (6300 frames) the Samsung 2, 11" dropped 0 frames, while the Acer CB3 and the Bay Trail didn't fair so well, dropping 1014 frames. This video was quite choppy, especially during scenes with lots of movement. The GPU would be the difference here.

For reference, I used this video: People Are Awesome Women's Edition 7 2014 Full HD 1080p

60 frames per second YouTube video
High framerate video is fairly new to YouTube, so I'll go ahead and say that it's potentially not optimized for all devices or 64-bit versions of Chrome OS. High framerate video is mostly interesting for video games and competitive play, in fact most people don't like the look of it for real-life footage.
The high framerate version of the video used for testing is only available on 720p and 1080p settings, so I used the 720p setting.
Over the course of one minute and twelve seconds (4,320 frames, remember there's 60 each second this time) the Samsung 2 dropped 4 frames, while the Acer CB3 and its Bay Trail processor dropped 798 frames. The video did not look like 60 frames per second most of the time on the Acer, so it wasn't handling this one well.

Video used: Battlefield Hardline: Multiplayer Trailer 60 FPS

Scrolling smoothness on various, single webpages
I might need some requests here, and I'll go ahead and mention that I have plug-ins set to "click to play" unless the page needs it like Spotify does.
For the following tests I turned on Chrome OS's fps counter, found at chrome://flags/#show-fps-counter, to watch frame rates on these pages.

Google+: Both Chromebooks kept framerates almost always over 50 for smooth results. Both Chromebooks stuttered as they neared the bottom of the page, which is when more content begins loading in.
TheVerge: Both Chromebooks kept framerates almost always over 50 for smooth results.
Gmail: I experienced framerates of between 18~23 on the Samsung 2, 11" and framerates of between 20~25 on the Acer CB3. Neither feels perfect, but the Bay Trail n2830 handles it just that much better.
Sample Google Doc: I experienced framerates of between 26~32 on the Samsung 2, 11" and framerates between 20~22 on the Acer CB3. This document, for reference: https://docs.google.com/document/d/1lQf7Vj9Q-1woSza5una3AjjBB2yEzBVoI2HUAlSw-Qw/edit?usp=sharing

Scrolling smoothness on one webpage while an "HD" video is displayed on second monitor
I do this fairly often when I can't cast a video to Chromecast, but I don't know if this is all that common among Chromebook users. I want to mention that a video playing in another tab of the same window doesn't usually render the video content when you're not viewing that tab (this may depend on the video player and website), so it's important to move the video out to another window to replicate this test.

On Google+, I got framerates of between 33~38 on the Samsung 2, 11", framerates between 25~29 on the Acer CB3, and both with stuttering as you near the bottom (where it begins to load more content).
For reference, I used this video after turning on the HD video quality: http://www.polarisgo.com/video/2beGpqd10YoR/category/shows/tag/table-flip/series/table-flip

Scrolling smoothness on one webpage while casting a tab to a Chromecast
Something I do less often, because honestly tab casting hasn't worked on my Samsung 2, 11" for the past several iterations of Chrome OS, but luckily the latest version is working. Both are using the normal version of the Google Cast extension set on 480p casting quality.
On Google+, I got framerates of between 19~23 on the Samsung 2, 11" with very poor framerates on the Chromecast, and framerates of between 6~15 on the Acer CB3 with an often smooth 30 frames on the Chromecast.

Android Apps?
The fps counter stays open on the new Android app ports so I thought I would test them out.
Vine: Stays above 50 fps on both after settling on a Vine to watch, a little stuttering while loading/scrolling through Vines.
Evernote: This was a little harder to find something to test, so I just found a note and scrolled on that; on the Samsung 2, 11" I saw framerates stay around 44, and on the Acer CB3 I saw framerates stay around 38.
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