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Everything I Know About SSDs

kcall.co.uk

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Re: Everything I Know About SSDs

#11

Post by fareesh »

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 to do with "sleep mode" or something like that. I always shutdown via software though.

Re: Everything I Know About SSDs

#13

Post by creeble »

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?

Re: Everything I Know About SSDs

#14

Post by 24gttghh »

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 turbine.

Now I'm no nuclear scientist so please be forgiving with that description, but that's how I understand them to work :)

I can't even begin to explain how an SSD works, but I know there are no moving parts besides electrons.

edit: moved the "(ideally)"

Re: Everything I Know About SSDs

#15

Post by leetcrew »

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.

Re: Everything I Know About SSDs

#16

Post by _hao »

cptskippy wrote: post #12

The CSS of this site manages to making reading this article equality inconvenient and painful on both Mobile and Desktop.

Same experience for me. Text seems readable and can be easily followed at 250% zoom (at least for me)

Re: Everything I Know About SSDs

#17

Post by notacoward »

Ariez wrote: post #3

I was under the impression that if you do not encrypt an SSD from the first use, then any attempt at overwriting with 0s is futile, as well as any other method to securely delete the files. The files will be easily recovered. This guy seems to say the opposite, in that the files are "simply not there anymore", contrary to everything I've read: who's right here?

The big problem with erasing SSDs is that when you think you're overwriting something you're actually writing new blocks (because of the translation layer). How many iterations do you have to do before you're certain to have actually hit every physical block? Nobody knows. Maybe infinite. Non-zero data blocks might not be readable through the flash drive's front-end interface, but they're still sitting there on the actual NAND chips. That's why secure erase was added (and even that seems to be less than fully trustworthy).

Re: Everything I Know About SSDs

#18

Post by cptskippy »

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.

Re: Everything I Know About SSDs

#19

Post by leetcrew »

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…

might be an innocent config issue, but this usually means the drive detection timed out during boot, which can be an early sign of drive failure. one of my old ssds behaved this way for a while before never being detected again. make sure you have anything important backed up.

Re: Everything I Know About SSDs

#20

Post by bitexploder »

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.
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