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I am not entirely sure that HAMR will be too different from CMR/PMR drives. The premise of HAMR is that they heat the area under the head, expanding it, for re
by pclmulqdq 3y ago
I am not entirely sure that HAMR will be too different from CMR/PMR drives. The premise of HAMR is that they heat the area under the head, expanding it, for reads and writes, and otherwise they are essentially CMR devices. This isn't like SMR, which had huge implications for drivers (due to the overlap in the bit lines). There must be a significant durability cost to HAMR, but I don't think the difference in drivers will be nearly as big for HAMR as it was for SMR.
- robotnikman 3y agoI'm guessing then that they will probably use a little bit more power then, but otherwise similar to CMR/PMR in performance. That heated head element though seems like a massive point of failure, though I have no idea how durable the technology it.
- dgacmu 3y agoThe heating is done by a solid state laser diode. It should be very reliable other than adding one more thing to an already complex drive head. (Which undoubtedly means the first generation or two will have some kinks to work out, but that's not a fundamental decrease, just engineering). And there shouldn't be much of an impact on durability. The heating is very brief - a nanosecond or so. The idea is not to expand the material physically, it's to increase its magnetic permeability temporarily so that you can write the bit to it and then it becomes stable again.
- rainbowzootsuit 3y agoThe nanoscale heating manipulates the magnetic coercivity of the platter coating to allow the magnetic polarization to be manipulated. It seems somewhat analogous to modern day Magneto Optical but much finer scale and the readout is via a magnetic signal vs MO using an optical readout.