Silly suggestion
Why on earth would you need to expose it as two drives? SATA/SAS already queue up tons of requests and the drive is already allowed to service them in non-linear order, as long as it's within the timeout. That's one of the pivotal parts of AHCI that makes it a huge improvement over ATA (Legacy) mode. If you have a parallel workload that wouldn't benefit from the improved random workload, then you can gain no benefit out of the dual heads at all anyway.
Displaying it as two hardware drives just sounds like a good way to confuse the hell out of most operating systems. Just internally split it into zones of some megabytes each, that'll nicely split up data. I suppose include an initialization command so that the OS can see both if it REALLY wants to micromanage it.
Biting the hand that feeds IT
