Intel's Galileo Development Board features the Intel Quark SoC X1000 Application Processor with a Pentium-class 32-bit 400MHz processor. The board retails for just over $50 USD and has 10/100 Ethernet, USB 2.0 support, and other options. The Intel Quark SoC X1000 is single-core and runs at 400MHz and has a 16KB cache. Again, it's main focus is on the very low power envelope and to be used in wearable computing devices and other very low-power, low-performance-requirement situations.
Kurt Keville over at MIT who I've collaborated with on various Linux performance projects -- most notably with a 96-core ARM solar-powered super computer -- through their use of the Phoronix Test Suite and OpenBenchmarking.org, has been running some Phoronix benchmarks on the Intel Galileo Board with Quark X1000. The benchmarks were done from a Debian 6.0 chroot and using the Linux 3.8 kernel.
Those curious about the Quark SoC X1000 Linux performance, there's benchmarks via Kurt's 1402191-SO-1402118PL06 result file. The results are compared against some of my recent low-power Linux testing for the Intel Bay Trail NUC Kit, etc. Embedded below are just some of the results.
Interestingly, the Intel Galileo runs Wayland's Weston.
The max TDP on the Quark X1000 SoC is just 2.2 Watts, so on a performance-per-Watt basis the numbers should be more interesting.
Unfortunately I don't have an Intel Galileo Board right now for running my own Linux benchmarks of this System-on-a-Chip.
See the rest of the benchmarks.