I'm not sure what this means, but we have 3 of these SiFive boards doing builds[1], as well as dozens of qemu instances running on Intel hardware supplied by Facebook. We use the SiFive boards for the largest builds however, things like GCC and the kernel, because they're still much better than qemu.
[1] Or we were up to yesterday when we had a hardware failure (on an Intel machine) so our build system is currently down. Four days before Christmas, so the worst possible time ...
[1] Or we were up to yesterday when we had a hardware failure (on an Intel machine) so our build system is currently down. Four days before Christmas, so the worst possible time ...