Author Topic: SSDs are overrated  (Read 3729 times)

SSDs are overrated
« on: 08 September, 2019, 12:39:32 pm »
I've just replaced the hard drive (320gb) on my netbook (Ubuntu Mate) with a 1TB ssd.  Yes, loading from drive is quicker but overall it doesn't make much difference in speed, as most computing processes run from RAM.

So, in speed SSDs are overrated for their price, which is about 5 times more than a spinning disk in £/GB. Ie they are not 5 times better.

And the new ssd cost nearly 5 times what I paid for my 2nd hand netbook. Yes SSDs have other benefits.

Pingu

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    • the Igloo
Re: SSDs are overrated
« Reply #1 on: 08 September, 2019, 12:55:31 pm »
Well, there's no way I'm going back to an HD on this lapdog. YMMV, ATS.

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: SSDs are overrated on Linux
« Reply #2 on: 08 September, 2019, 12:56:43 pm »
Depends on your OS. Init.
It is simpler than it looks.

Gattopardo

  • Lord of the sith
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Re: SSDs are overrated
« Reply #3 on: 08 September, 2019, 01:07:53 pm »
Also depends on the swap file size...

FifeingEejit

  • Not Small
Re: SSDs are overrated
« Reply #4 on: 08 September, 2019, 01:09:02 pm »
Maybe it says more about Ubuntu than the SSD...


But even more importantly... what you're doing matters.
Anything that involves a lot of read/write to storage but little computation is going to gain from higher transfer and access speeds.
Anything that's computationally heavy with little persistence is going to gain from a faster processor.

ian

Re: SSDs are overrated
« Reply #5 on: 08 September, 2019, 01:10:35 pm »
The difference when I fitted one to an old Mac Mini was amazing. In fact, it's still running fine, and it's a decade old. I wouldn't touch a spinning disk now. It might be true that most processes run from RAM these days, but it has to get into the RAM first. Most modern OSes are optimised with SSDs in mind.

FifeingEejit

  • Not Small
Re: SSDs are overrated
« Reply #6 on: 08 September, 2019, 01:13:37 pm »
The difference when I fitted one to an old Mac Mini was amazing. In fact, it's still running fine, and it's a decade old. I wouldn't touch a spinning disk now. It might be true that most processes run from RAM these days, but it has to get into the RAM first. Most modern OSes are optimised with SSDs in mind.

Spinny discs still have their place;
There's limited advantage from keeping your photos (or anything else that can be loaded into memory from spinny disc when required) on an SSD; yes it'll load slightly faster but do you care enough?
It's more likely that spinny disc will be in a SAN, NAS or cloud accessed storage farm these days.

ian

Re: SSDs are overrated
« Reply #7 on: 08 September, 2019, 01:22:24 pm »
I meant inside the computer of the OS – my backups and the external storage drives still giddily spin, there's no need for any kind of speed. All my media and photos sit on a USB connected spinning drive.

fuaran

  • rothair gasta
Re: SSDs are overrated
« Reply #8 on: 08 September, 2019, 02:17:28 pm »
The netbook is probably limited by the processor speed.
And the disk interface. If it is SATA I, that's only 150MB/s, not much faster than a hard drive. SATA III is up to 600MB/s.
Newer SSDs can use M2 NVME, which can be a lot faster.

Re: SSDs are overrated
« Reply #9 on: 08 September, 2019, 02:57:22 pm »
I think it's SATA 2, up to 3 Gbit/s, 300 MB/s.

CPU is Atom N570 1.66GHz dual core.

Kim

  • Timelord
    • Fediverse
Re: SSDs are overrated
« Reply #10 on: 08 September, 2019, 05:06:06 pm »
I've just replaced the hard drive (320gb) on my netbook (Ubuntu Mate) with a 1TB ssd.  Yes, loading from drive is quicker but overall it doesn't make much difference in speed, as most computing processes run from RAM.

So, in speed SSDs are overrated for their price, which is about 5 times more than a spinning disk in £/GB. Ie they are not 5 times better.

"I bought a new car but it hasn't made my bike any faster."

Re: SSDs are overrated
« Reply #11 on: 08 September, 2019, 05:23:04 pm »
I've just replaced the hard drive (320gb) on my netbook (Ubuntu Mate) with a 1TB ssd.  Yes, loading from drive is quicker but overall it doesn't make much difference in speed, as most computing processes run from RAM.

So, in speed SSDs are overrated for their price, which is about 5 times more than a spinning disk in £/GB. Ie they are not 5 times better.

"I bought a new car but it hasn't made my bike any faster."

But it has made my computer faster!

Re: SSDs are overrated
« Reply #12 on: 08 September, 2019, 05:36:00 pm »
I thought (had read somewhere on a forum  when I was thinking of disc replacement for my N 270 netbook)that putting an ssd in a netbook was considered to be always not worth the money as it would be cheaper to buy a new netbook!

I won't pass comment on Mate. I tried it on a Pi and went back to Raspbian very quickly! 

Kim

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    • Fediverse
Re: SSDs are overrated
« Reply #13 on: 08 September, 2019, 05:38:58 pm »
I've just replaced the hard drive (320gb) on my netbook (Ubuntu Mate) with a 1TB ssd.  Yes, loading from drive is quicker but overall it doesn't make much difference in speed, as most computing processes run from RAM.

So, in speed SSDs are overrated for their price, which is about 5 times more than a spinning disk in £/GB. Ie they are not 5 times better.

"I bought a new car but it hasn't made my bike any faster."

But it has made my computer faster!

Well a faster car might give you time for more CAKE when you drive to the start of the ride...


I'd expect a substantial speedup of reads - especially random reads - with an SSD compared to spinning rust, and if my computer was slow due to poor storage throughput, that's what I'd upgrade to speed it up.  If it was slow at some CPU/memory/network-bound operation, I wouldn't expect any improvement.  If someone's given you the impression that SSDs are a magic box of 'more speed' you can add to your computer, then that's a misleading oversimplification - it doesn't mean that SSDs are in general overrated, they're still a step-change in performance compared to magnetic disks, and usually more reliable.

(FWIW, I find that Windows desktop systems seem to spend more time thrashing disk than Linux ones do, which means more IO-bound tasks that can potentially be speeded up with faster storage.)

fuaran

  • rothair gasta
Re: SSDs are overrated
« Reply #14 on: 08 September, 2019, 06:12:40 pm »
I thought (had read somewhere on a forum  when I was thinking of disc replacement for my N 270 netbook)that putting an ssd in a netbook was considered to be always not worth the money as it would be cheaper to buy a new netbook!
You could get a decent 250GB SSD for about £30. A lot cheaper than a new netbook anyway. Gets more expensive if you want a 2TB SSD, but a new netbook won't have a 2TB SSD anyway.
And probably be noticeably faster. Also lower power consumption than a hard drive. And less breakable, if the netbook gets dropped.

Re: SSDs are overrated
« Reply #15 on: 08 September, 2019, 06:34:43 pm »
The netbook is probably limited by the processor speed.
And the disk interface. If it is SATA I, that's only 150MB/s, not much faster than a hard drive. SATA III is up to 600MB/s.
Newer SSDs can use M2 NVME, which can be a lot faster.

My understanding is those interfaces are really only faster in benchmarks where they e.g. read a very large file all at once continuously, but almost no real world application does that often. Everything else is random access and limited by overhead and latency, or limited by the interface of the other device the data is coming from / going to.

Re: SSDs are overrated
« Reply #16 on: 08 September, 2019, 06:45:08 pm »
A lot depends upon what sata interface your machine has.

SSD's use less electrickery, will be faster on i/o if your machine supports this, makes lots less noise and generally will be more reliable.

I would never go back to clunky old platters now.

Kim

  • Timelord
    • Fediverse
Re: SSDs are overrated
« Reply #17 on: 08 September, 2019, 06:53:28 pm »
My understanding is those interfaces are really only faster in benchmarks where they e.g. read a very large file all at once continuously, but almost no real world application does that often.

I expect the bulk of the large continuous reads is copying files.  Not that speeding up copying files isn't a useful thing to want to do, but it's quite specific.

Phil W

Re: SSDs are overrated
« Reply #18 on: 08 September, 2019, 06:58:46 pm »
Magnetic tape drives can sustain 240Mb/s sequential write speed.  The forgotten cousin of storage. Always used to amuse me that for sequential I/O magnetic tape exceeded disk speeds for a long time. So was a good choice for certain applications / situations.

Kim

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    • Fediverse
Re: SSDs are overrated
« Reply #19 on: 08 September, 2019, 07:01:54 pm »
Magnetic tape drives can sustain 240Mb/s sequential write speed.  The forgotten cousin of storage. Always used to amuse me that for sequential I/O magnetic tape exceeded disk speeds for a long time. So was a good choice for certain applications / situations.

Generally the same sort of applications where spinning (or mostly-not-spinning) rust still makes sense over SSD...

Magnetic disk is the new magnetic tape.

Phil W

Re: SSDs are overrated
« Reply #20 on: 08 September, 2019, 07:08:55 pm »
Indeed just as SSD will become obsolete should the new computer architectures which aren't Von Newman based, escape the lab and come into commercial production.  Then talk of disk drives spinning or SSD will be like talking about the days of the Ark.

Re: SSDs are overrated
« Reply #21 on: 08 September, 2019, 07:20:45 pm »
I expect the bulk of the large continuous reads is copying files.  Not that speeding up copying files isn't a useful thing to want to do, but it's quite specific.

Yeah, but where are you copying them to? Unless it's a second internal SSD with just as fast an interface, it's the speed of the other device that's the limiting factor.

(there's the specific edge case of duplicating on the same drive, although some modern filesystems can do that in O(1) regardless of drive speed)

Afasoas

Re: SSDs are overrated
« Reply #22 on: 10 October, 2019, 10:27:00 pm »
I'd suspect the IO bus in the netbook isn't really best placed to capitalise on the SSD ... but I've revived many an old machine with a small SSD.

Been involved in benchmarking a range of SSDs with real world workloads. Published benchmarks are almost meaningless. Seems the SSD manufacturers tend to use the cheapest/slowest TLC NAND for the bulk of the drive and beef it up with some faster SLC or MLC NAND for caching purposes. How much of this faster performing NAND they provide varies broadly in-line with how much you pony up. The cheapest drives are TLC NAND without any cache. Some of the cheaper SSDs that aren't taking advantage of 3D or Vertical NAND are terrible and not much better than HDDs.

Adam

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Re: SSDs are overrated
« Reply #23 on: 11 October, 2019, 04:17:59 pm »
Magnetic tape drives can sustain 240Mb/s sequential write speed.  The forgotten cousin of storage. Always used to amuse me that for sequential I/O magnetic tape exceeded disk speeds for a long time. So was a good choice for certain applications / situations.

Generally the same sort of applications where spinning (or mostly-not-spinning) rust still makes sense over SSD...

Magnetic disk is the new magnetic tape.

20 years ago, at my old work I instigated a document imaging project and we installed HP magneto-optical disks, which were about the size of the old 5" floppies but ½" thick.  Each disk had a capacity of 9.1 GB and we had 2 jukeboxes full of them, so at least 40 disks, meaning a 10 second delay as the mechanism grabbed the correct disk to then load up the scanned file.  They guaranteed the integrity of the data for 100 years, which is handy for financial services stuff.

All got ditched within a few years first to a RAID array, and then into the cloud.
“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein

ian

Re: SSDs are overrated
« Reply #24 on: 11 October, 2019, 08:59:38 pm »
Some in the midden cupboard of IT archaeology I have a Seagate magneto-optical disk, I think the disks might have clocked up to 10 MB. All I remember is that it was big hunk of hardware and connected via RS232 which meant transfer speeds were slower than a vibrating piece of string and each disk cost something extraordinary. I think it was killed by Zip drives. Children, ask your parents.