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Re:How “latency numbers everybody should know” decreased fro... by ZainRiz on Thursday March 03, 2022 @08:10PM (#30549303)
Actually, this data is all false from 2012 onwards.

The code was written back in 2012 and is using numbers from back then to _guess_ what future numbers would look like!

(I was fooled by it too)

See https://github.com/colin-scott/interactive_latencies/issues/...

Re:How “latency numbers everybody should know” decreased fro... by Dylan16807 on Thursday March 03, 2022 @10:25PM (#30550329)
Even the 2012 data is suspect.

"Seek + rotational delay halves every 10 years" just isn't true. We got rid of the >7200 drives and are basically sitting still on that metric. And hard drives weren't at 400MB/s in 2012 either. (The disk bandwidth section also cites a 2012 presentation with correct numbers, but something went wrong in translation.)

Re:How “latency numbers everybody should know” decreased fro... by marcan_42 on Friday March 04, 2022 @02:46AM (#30551830)
Yeah, I was wondering where the heck 2ms disk seek times came from. That's not a thing and will never be a thing; disks only spin so fast, and nobody even uses >7200RPM drives any more (because we've all moved to SSDs instead).
Re:How “latency numbers everybody should know” decreased fro... by bufferoverflow on Friday March 04, 2022 @04:26AM (#30552457)
Oh 7200 drives are used. Mainly for large data storage. If you deal with high quality videos (RAW 4K or 8K), SSDs are way too expensive to store them.
Re:How “latency numbers everybody should know” decreased fro... by mjochim on Friday March 04, 2022 @04:41AM (#30552557)
GP was likely refering to extraordinary disks with more than 7200 rpm
Re:How “latency numbers everybody should know” decreased fro... by thisisnico on Friday March 04, 2022 @11:10AM (#30556655)
10KRPM SAS drives in my SAN.
Re:How “latency numbers everybody should know” decreased fro... by quietbritishjim on Friday March 04, 2022 @04:40AM (#30552554)
The parent comment said no one uses drives strictly faster than 7200.
Re:How “latency numbers everybody should know” decreased fro... by bufferoverflow on Friday March 04, 2022 @05:02AM (#30552680)
Pretty sure 10K RPM drives are used too.
Re:How “latency numbers everybody should know” decreased fro... by vidarh on Friday March 04, 2022 @05:10AM (#30552748)
They're used, but rare because they got to a weird position in between slower drives that are cheaper to produce and operate and SSDs. E.g. 15K RPM drives were a thing but while you can still buy some models they're typically more expensive than SSDs, so you mostly buy them to replace drives in existing arrays.
Re:How “latency numbers everybody should know” decreased fro... by quietbritishjim on Friday March 04, 2022 @05:05AM (#30552705)
I have no opinion on the matter, just pointing out that your comment doesn't follow from the previous one. But I imagine that when they said "nobody" uses faster disks, they were exaggerating a bit. The question is whether the default set of "latency numbers everyone should know" should reference SSDs or uncommon spinning disks.
Re:How “latency numbers everybody should know” decreased fro... by ChuckMcM on Thursday March 03, 2022 @11:56PM (#30550855)
Looks like a fun project to bring it up to date.
Re:How “latency numbers everybody should know” decreased fro... by gurjeet on Friday March 04, 2022 @12:35AM (#30551059)
Where would one lookup such data, if one is interested in updating the code.
Re:How “latency numbers everybody should know” decreased fro... by ChuckMcM on Friday March 04, 2022 @12:41AM (#30551094)
I would start by going through the Anandtech reviews of the major processor and storage announcements. They generally do a great job of benchmarking and go into pretty good detail. Datasheets from manufacturers would also be useful although not all data is routinely provided.
Re:How “latency numbers everybody should know” decreased fro... by saagarjha on Friday March 04, 2022 @01:08AM (#30551248)
This is the kind of thing you’d typically experimentally verify rather than look up.