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Re: Question: SSD speed



Jeremy Nicoll <jn.ml.dbn.25@letterboxes.org> wrote:
> On Wed, 7 Oct 2020, at 09:39, Hans wrote:

>> I have a little question. Smartctl is telling me, that my ssd drive
>> is 6Gb/sec capable, but the actual speed is only 1,5GB/sec.

> If your SATA (presumably) connection from the machine to the SSD is a
> 6 Gbps one, the maximum data transfer speed in bytes across that
> connection would be one eighth of that (as there's 8 bits per byte),
> so about 760 MBps.

> That's about half of your "1,5GBps".  That makes me wonder if your SSD
> uses two SATA channels at once - is that even possible?

Only with SAS drives. And usually only for redudancy and not for
concurrency.

I question the benchmark Hans did.

Something tells me he either used "hdparm -tT", which is known to
misrepresent the speeds on modern drives, or wrote too little data so he
was benchmarking the Kernel cache and not the drive.

S!

-- 
Sigmentation fault. Core dumped.


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