"There are several situations when the PWC with PLP comes into play, with the main one being when the HDD write cache contains data not yet written to media and a power loss occurs, the data is moved to non-volatile memory."
Does this mean than instead of streaming writes though the flash cache, writes normally go directly from the dram buffer to the platters and the flash cache is only invoked in the event of a loss of external power (and presumably powered by on board capacitors).
Back EMF, not capacitors - basically uses the HDD motor and platter inertia during the deceleration to generate the power needed to flush the DRAM to NAND.
Since this drive is targeted at enterprise customers, the warranty period is fairly standard. Corporate customers are usually more demanding about support after the sale than consumers, after all.
enterprise customers also generally follow through with demands for a longer warranty period vs the typical consumer that grumbles about crappy default options, but who then buys the absolute cheapest product in a category anywhere even though its warranty ends when the picker in the warehouse takes it off the shelf.
Why is the "average latency" at all worth mentioning? It's just the time for half a rotation, (1 / (7200/60)) / 2 = 0.00417, and is only a fixed part of the access time. And it's the same fixed time for all 7200rpm HDDs.
Why is there no mention of the NAND cache that these drives are supposedly equipped with? I understand that it is for data in flight protection but nothing more, this sounds like a standout feature but its given no more than a sentence of coverage....what gives?
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DanNeely - Monday, April 10, 2017 - link
"There are several situations when the PWC with PLP comes into play, with the main one being when the HDD write cache contains data not yet written to media and a power loss occurs, the data is moved to non-volatile memory."Does this mean than instead of streaming writes though the flash cache, writes normally go directly from the dram buffer to the platters and the flash cache is only invoked in the event of a loss of external power (and presumably powered by on board capacitors).
MrSpadge - Monday, April 10, 2017 - link
Very probably. Otherwise I don't see how they would achieve 550 TB/year over 5 years without significant cost.ZeDestructor - Monday, April 10, 2017 - link
Back EMF, not capacitors - basically uses the HDD motor and platter inertia during the deceleration to generate the power needed to flush the DRAM to NAND.leexgx - Thursday, April 20, 2017 - link
its the 128MB of cache that it has is the NANDScott_T - Monday, April 10, 2017 - link
I'm liking the return of warrantys longer than a year. Makes me a bit more confident using these humongous drives.BrokenCrayons - Monday, April 10, 2017 - link
Since this drive is targeted at enterprise customers, the warranty period is fairly standard. Corporate customers are usually more demanding about support after the sale than consumers, after all.DanNeely - Monday, April 10, 2017 - link
enterprise customers also generally follow through with demands for a longer warranty period vs the typical consumer that grumbles about crappy default options, but who then buys the absolute cheapest product in a category anywhere even though its warranty ends when the picker in the warehouse takes it off the shelf.MrSpadge - Monday, April 10, 2017 - link
With it being an Enterprise grade drive expect it to cost about twice as much as an equivalent consumer drive with lower warrenty.ajp_anton - Tuesday, April 11, 2017 - link
Why is the "average latency" at all worth mentioning? It's just the time for half a rotation, (1 / (7200/60)) / 2 = 0.00417, and is only a fixed part of the access time. And it's the same fixed time for all 7200rpm HDDs.creed3020 - Wednesday, April 12, 2017 - link
Why is there no mention of the NAND cache that these drives are supposedly equipped with? I understand that it is for data in flight protection but nothing more, this sounds like a standout feature but its given no more than a sentence of coverage....what gives?