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A 1TB laptop hard drive has ~100MB/s of I/O usually (unless its dying). Newer hard drives tend to be pretty snappy under Debian, unless your disk is degraded (e

by mehhh 7y ago

A 1TB laptop hard drive has ~100MB/s of I/O usually (unless its dying). Newer hard drives tend to be pretty snappy under Debian, unless your disk is degraded (eg: dying blocks causing I/O to chug, watch for SMART errors).

deleted 7y ago
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wtallis 7y ago
> A 1TB laptop hard drive has ~100MB/s of I/O usually (unless its dying). For sequential transfers, yes. But that's hardly ever the relevant figure for whether your system feels fast. You should be looking at the random read performance, where your hard drive is good for ~120 IOs per second and your SSD is good for several thousand at a minimum.
- amichal 7y ago
  This. Last magnetic laptop drive I had was measuring under 10MB per second with small random reads. On a fragged old OS install it’s unbelievably impactful. Back in windows 98 days simply copying my data to a second partiton, erasing and reinstalling the OS and copying ALL the data back would get me back to like new for a few months. When a drive is nearly full “defrag” is not that successful. Similar things happen with nearly full SSDs via other mechanisms
  - wtallis 7y ago
    If you were getting multiple MB/s, then your random reads weren't particularly small. A 1TB 3.5" 7200 RPM hard drive gives only 0.25–0.6MB/s for 4kB random reads depending on how much it is short stroked.
lathiat 7y ago
The problem with HDDs is rarely the sequential speed but the IOPS; of which you get around 100 per second. The problem is that since the majority of machines have SSDs now developers no longer optimise the number of IOPS or care about it; or notice it at all - as SSDs have orders of magnitude more IOPS performance than a HDD. Combine that with many people having quite a few background programs that will spew IOPS randomly you'd be surprised how fast the disk gets slow. Even MacOS which until recently (and maybe even now) sells machines with a HDD as standard; with pretty much no extra software installed is unbearably unusable on a HDD. SSDs are basically required at this point.
pixl97 7y ago
100MB/s of sequential transfers. Change that to 4k IO's and it can drop to 500KB/s on a laptop hard drive easily.

by mehhh 7y ago

deleted 7y ago

[deleted]

wtallis 7y ago

> A 1TB laptop hard drive has ~100MB/s of I/O usually (unless its dying). For sequential transfers, yes. But that's hardly ever the relevant figure for whether your system feels fast. You should be looking at the random read performance, where your hard drive is good for ~120 IOs per second and your SSD is good for several thousand at a minimum.

amichal 7y ago
This. Last magnetic laptop drive I had was measuring under 10MB per second with small random reads. On a fragged old OS install it’s unbelievably impactful. Back in windows 98 days simply copying my data to a second partiton, erasing and reinstalling the OS and copying ALL the data back would get me back to like new for a few months. When a drive is nearly full “defrag” is not that successful. Similar things happen with nearly full SSDs via other mechanisms
- wtallis 7y ago
  If you were getting multiple MB/s, then your random reads weren't particularly small. A 1TB 3.5" 7200 RPM hard drive gives only 0.25–0.6MB/s for 4kB random reads depending on how much it is short stroked.

lathiat 7y ago

The problem with HDDs is rarely the sequential speed but the IOPS; of which you get around 100 per second. The problem is that since the majority of machines have SSDs now developers no longer optimise the number of IOPS or care about it; or notice it at all - as SSDs have orders of magnitude more IOPS performance than a HDD. Combine that with many people having quite a few background programs that will spew IOPS randomly you'd be surprised how fast the disk gets slow. Even MacOS which until recently (and maybe even now) sells machines with a HDD as standard; with pretty much no extra software installed is unbearably unusable on a HDD. SSDs are basically required at this point.

pixl97 7y ago

100MB/s of sequential transfers. Change that to 4k IO's and it can drop to 500KB/s on a laptop hard drive easily.