unity dash is eating up power (>1W)

[Colin Ian King]

When running without the dash showing, unity on an idle system is consuming the following:

CPU: 3.11 Watts (std.dev. 0.17)
GPU: 0.65 Watts (std.dev. 0.30)
CPU is 96.8% resident in lowest C7 state
CPU is 98.9% idle, 709 context switches/sec
CPU @ 1.27 GHz (average)

(measured using sudo powerstat -Ra 5 12)

When I pop the dash up using the meta key, the system on idle consumes the following:

CPU: 3.40 Watts (std.dev. 0.14)
GPU: 1.27 Watts (std.dev. 0.27)
CPU is 97.216 resident in lowest C7 state
CPU is 98.0% idle, 776 context switches/sec
CPU @ 1.27 GHz (average)

So I'm seeing ~1/3 a Watt extra being used on the CPU and ~2/3 Watt extra on the GPU, or about 1 Watt extra overall. This is quite an overhead.