Re:Is sequential IO dead in the era of the NVMe drive?
by wtallis on Tuesday May 09, 2023 @07:37PM
(#35881750)
No, there really are invisible buffers resulting from this discrepancy. The raw flash chips have nominal capacities that align with power of two sizes, but the drives use decimal-based units. So a drive advertised as 1TB will have a usable capacity of approximately 1TB, but is assembled from flash chips with a total capacity of at least 1 TiB.
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Re:Is sequential IO dead in the era of the NVMe drive?
by cfinnberg on Wednesday May 10, 2023 @01:12PM
(#35890300)
Yes, there are invisible buffers, but the discrepancy doesn't come from this. Drive makers count the space in 1000 -multiple units (i.e. 1GB = 1000*1000*1000 bytes) whereas in computing units are usually count on 1024 -multiple (i.e. 1GiB = 1024*1024*1024 bytes)
So 1TB = 1000*1000*1000*1000 bytes/1024/1024/1024 = 931GiB (or 0.9TiB)
Re:Is sequential IO dead in the era of the NVMe drive?
by wtallis on Wednesday May 10, 2023 @05:57PM
(#35894053)
Did you notice the part where I explained how drive makers use the decimal units but the chips they source to build those drives are built in binary capacities?
I don't give a shit whether your operating system likes to show you disk usage in binary or decimal units, because I'm not talking about software at all. I'm explaining how the hardware is built. I especially don't need another person to try to explain what the binary and decimal units are, after I've repeatedly used both correctly.