The Discovery tablet and the test
At AMD's campus in Austin, we were given a few hours to test the Discovery Project tablet, an 11.6" slate powered by the fastest Mullins variant. The device featured a 1920x1080 display resolution, 2GB of memory, a 64GB solid-state drive, Bluetooth, Wi-Fi, GPS, and all the other bits and pieces one would expect to find in a Windows 8.1 tablet. AMD described the Discovery tablet as a "fully featured product with everything Mullins has to offer." This was no product, of course. It was an "internally developed" reference machine intended as a showcase for the press and AMD's partners.
Still, it worked well, and it didn't look half bad.
The system was set up with Windows 8.1 and a number of applications intended for us to test. We didn't use the AMD-provided benchmarks, though. Rather, we came armed with a USB 3.0 solid-state drive containing our own test apps and games. We brought the latest versions of 7-Zip, LuxMark, Musemage, TrueCrypt, the x264 encoder, 3DMark, BioShock Infinite, DiRT Showdown, and Tomb Raider. We also ran the latest SunSpider and Kraken web benchmarks.
We didn't have time to install a clean version of the operating system, but we did check the "Uninstall" and "Power Options" control panels, among other things, to make sure the test conditions were as clean as our schedule would permit. We also configured the operating system the way we usually do, disabling things like Windows Defender and System Protection, to ensure fair and comparable results.
For comparison, we ran the same tests on Asus' Transformer Book T100 convertible tablet, which is based on Intel's Bay Trail processor, and the Kabini whitebook AMD sent us last year. (A small caveat: while the AMD systems both ran Windows 8.1 x64, the Transformer was stuck with Windows 8.1 x86, since it lacks 64-bit support.) For our web and 3DMark tests, we also threw in data from Google's second-gen Nexus 7 slate and from Nvidia's Shield handheld, which both ran Android 4.4 KitKat. The Shield may not be a tablet, but it provides a glimpse at the unbounded performance of Nvidia's Tegra 4 processor, which is helpful as a point of reference.
Memory subsystem performance
The Mullins tablet had the least memory bandwidth of the three systems we tested. That's not too surprising, because the A10 Micro-6700T is limited to a single channel of 1333MHz memory. By contrast, the A4-5000's single-channel controller supports faster 1600MHz RAM. The Atom Z3740 is limited to a 1066MHz memory speed, but its second memory channel more than makes up the deficit.
Low memory bandwidth or not, Mullins performs pretty nicely in these productivity tasks. The A10 Micro-6700T actually matches or outperforms the A4-5000 despite its lower base clock speed and tighter TDP. Credit for that performance should probably go to the new Turbo mechanism, which can push the Micro-6700T from its base frequency of 1.2GHz to as much as 2.2GHz—well above the A4-5000's 1.5GHz maximum.
Mullins fares quite nicely against the Atom, too. It's faster in x264 and TrueCrypt, and it's not very much slower in 7-Zip. Of course, the Atom does have a lower SDP: 2W, compared to 2.8W for the A10 Micro-6700T.