Everything I Know About SSDs • Hacker News Board

Re: Everything I Know About SSDs

#31

Post by winrid » Wed, Jan 15, 2020, 4:45 PM UTC

trymas wrote: post #21

cattlemansgold wrote: post #8

There are a few technologies that I’ve tried very earnestly to understand, only to find out that it’s basically black magic and there’s no use in trying to understand it. Those things are modern car transmissions, nuclear reactors, and SSDs.

> Those things are modern car transmissions, .. Even though it may be off-topic, but could you elaborate on this a little bit more?

Not OP but in my experience people tend to have trouble comprehending systems of planetary gear sets.

Although modern automatics are probably a bit easier to understand than old ones, especially CVTs? As long as you're ok with "the computer just triggers this solenoid.." rather than understanding a big hydrualic computer.

Re: Everything I Know About SSDs

#32

Post by occamrazor » Wed, Jan 15, 2020, 4:45 PM UTC

cbdumas wrote: post #30

I love a minimal, text-only website as much as the next crotchety HN reader, but a little bit of CSS goes a very long way in terms of readability. Edit: Upon further inspection I see that this page was designed to be hard to read. Very curious.

Reader view helps a lot, and with such a simple website it is guaranteed to give a good result.

Re: Everything I Know About SSDs

#33

Post by leetcrew » Wed, Jan 15, 2020, 4:46 PM UTC

cm2187 wrote: post #22

leetcrew wrote: post #15

Earlier quoted context omitted.

I believe all major OSes support trim in a reasonable way now. afaik it needs hardware support though, so idk how it would work for an SD card.

Unless you have a RAID card in the middle.

I don't mean to say it wouldn't work, just that I don't know enough about sd cards to say whether it would/should.

Re: Everything I Know About SSDs

#34

Post by fareesh » Wed, Jan 15, 2020, 4:47 PM UTC

cptskippy wrote: post #18

fareesh wrote: post #11

I wonder if anyone here has experienced something similar: I have a Samsung Evo 860 SSD. Sometimes after powering on my desktop the BIOS either "forgets" the drive (sets some other drive as primary boot drive) or doesn't recognize it at all. The non recognition issue goes away after I power off and power on. It's been this way for about 8 months. Happens every 1/15 times I power on. I've heard it may have something t…

That sounds like the drive is failing to initialize in time. Have you tried enabling a POST test or Boot Delay? I suspect the problem might magically go away if you do.

I'll try it out

Re: Everything I Know About SSDs

#35

Post by zzzcpan » Wed, Jan 15, 2020, 4:47 PM UTC

24gttghh wrote: post #14

cattlemansgold wrote: post #8

There are a few technologies that I’ve tried very earnestly to understand, only to find out that it’s basically black magic and there’s no use in trying to understand it. Those things are modern car transmissions, nuclear reactors, and SSDs.

A very basic nuclear reactor can be explained pretty simply I think. You enrich a bunch of let's say uranium. Pack it together in a rod, and put a bunch of those rods in a pond. Those rods have controlled (ideally) nuclear decay from their being in close proximity to other rods which generates a lot of heat, which is transferred to a separate cooling loop that boils water to make steam which drives an electric turbin…

You can explain SSD as a controller you send commands to that writes data to and reads from a log structured storage on top of raw flash.

Re: Everything I Know About SSDs

#36

Post by monocasa » Wed, Jan 15, 2020, 4:49 PM UTC

leetcrew wrote: post #15

creeble wrote: post #13

Anyone know how TRIM works with Linux? I find myself copying entire partitions between SSDs from time to time, is there a utility to clear the destination SSD before copy? Is it possible to do the same for an SD card, so that writing a new Raspi OS to it doesn't do unnecessary garbage collection?

I believe all major OSes support trim in a reasonable way now. afaik it needs hardware support though, so idk how it would work for an SD card.

MMC defines trim as an optional command. But maybe to your point I've generally only seen it implemented on eMMC chips, not SD cards.

Re: Everything I Know About SSDs

#37

Post by quartz » Wed, Jan 15, 2020, 4:55 PM UTC

cattlemansgold wrote: post #8

There are a few technologies that I’ve tried very earnestly to understand, only to find out that it’s basically black magic and there’s no use in trying to understand it. Those things are modern car transmissions, nuclear reactors, and SSDs.

There's a pretty succinct (2 minute) non-engineering description of how a nuclear reactor works in the Chernobyl miniseries you might want to check out: https://www.youtube.com/watch?v=BpwU4mtWXAE

Re: Everything I Know About SSDs

#38

Post by cm2187 » Wed, Jan 15, 2020, 4:55 PM UTC

leetcrew wrote: post #33

cm2187 wrote: post #22

Earlier quoted context omitted.

Unless you have a RAID card in the middle.

I don't mean to say it wouldn't work, just that I don't know enough about sd cards to say whether it would/should.

Sorry, I meant for TRIM being passed down to an SSD.

Re: Everything I Know About SSDs

#39

Post by Kirby64 » Wed, Jan 15, 2020, 5:02 PM UTC

bitexploder wrote: post #20

cattlemansgold wrote: post #8

There are a few technologies that I’ve tried very earnestly to understand, only to find out that it’s basically black magic and there’s no use in trying to understand it. Those things are modern car transmissions, nuclear reactors, and SSDs.

My car doesn't even have a transmission. Seriously though, a long time ago, I tore down a 1990 Mustang Automatic transmission and rebuilt it myself and, even back then, it was an amazing piece of machinery. The planetary gear systems are really cool. I don't think I completely understood it, but it was a lot of fun. It did take me two months, heh.

I assume you have an EV? Even EVs have transmissions (unless it's some weird niche car that's completely direct drive). They're just vastly simpler than modern automatic/manual gearboxes, usually a single gear reduction.

Re: Everything I Know About SSDs

#40

Post by ololobus » Wed, Jan 15, 2020, 5:03 PM UTC

"As for writes, at 1 gb a day - far more than my current rate of data use - it would take the same 114 years to reach 40 tb."

Maybe it works for author's very specific system or use-case, but on my personal MBP laptop with very occasional usage pattern--some days I do not use it at all during the week--I end up with 10 GB per day of writes on average. That way it will be 11.4 years already, not so many. And I do not do something very disk-expensive on it like torrents downloading or database testing, only some general development task, watching online videos, web surfing, docs, etc.