You can refer to our article called Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology In Depth for details on this test. We will just list the specific modes we measure the power consumption in:
- Start (the current the drive consumes when starting up)
- Idle (the drive is not accessed at all, but it is turned on and ready to work)
- Random Read and Write
- Sequential Read and Write
Let’s check out each mode one by one.
Funnily enough, the weakest controller is not the most economical. The JMicron-based products need less power than the top-performance X128 and X25-M to start up, but are not as economical as the Corsair P128.
This peak startup consumption is not crucial for flash memory, though.
What is more important, the three JMicron-based models are the most voracious in idle mode. This controller seems to be as simple as to lack any reduced-consumption modes.
Corsair’s SSDs are the most economical here: the P128 needs a third of a watt, and the X128 needs half a watt.
Note that this power consumption is not very low by the standards of HDDs of the same 2.5-inch form-factor. 2.5-inch HDDs need about as much power in idle mode as the more voracious of these flash-memory drives.
We’ve got similar standings when doing random-address reading and writing, but the X128 takes first place. We wonder how it manages to deliver the same writing performance as the X25-E while being as economical as the P128.
As opposed to HDDs, SSDs consume more power when writing. The difference between reading and writing is almost twofold. As a result, the SSDs reach a power draw of 2.5W (and the PQI needs even more) which is the maximum amount that a single USB 2.0 port can yield. SSDs and 2.5-inch HDDs are comparable in power consumption in this operation mode.
When data is sequential, the SSDs need more power for reading (multi-channel access puts a load on the controller as well as memory chips) but less for writing it. The only exception is the Intel X25-M whose power consumption grows up at writing, too. Like the low speed of writing, this must be the tradeoff of its architecture which is so effective at processing small data blocks. Corsair’s drives win this test with almost identical results.