Techquickie on SSD overprovisioning

[Enderman]

 

Script @39 seconds: "Why does your computer tell you the actual capacity is far lower??"

 

It doesn't.......

It literally says in the middle of the screenshot "512,108,785,664 bytes"

That is 512GB.

The number on the right is GiB not GB, windows just shows it as GB.

 

For example with the 850 Pro, you pay for a 512GB SSD and you get exactly 512GB, not 476.

Any overprovisioned space is not shown through file explorer or disk management.

Whoever is writing these scripts probably needs to be a bit more informed on the subject of GiB vs GB and how to properly see how much space their drive has.

[desertcomputer]

Well for most average users/consumer they think it actually lower ... As the box said "128GB" and the drives shows around "115" on windows or mac at a glance. 

 

I presume the video script was written for novice users. 

[79wjd]

15 minutes ago, MrUnknownEMC said:

Well for most average users/consumer they think it actually lower ... As the box said "128GB" and the drives shows around "115" on windows or mac at a glance. 

 

I presume the video script was written for novice users. 

But the video is saying that part of the reason it says 476 instead of 512 is because over overprovisioning....which isn't the case at all. 512GB = 476GiB. 

 

Overprisioning is the fact that the drive might have 600GB in NAND chips on the board, but only 512GB is actually usable by the computer and the rest is for the drive to ensure it doesn't go below that 512GB mark.

 

Saying that Windows shows 476 instead of 512 because of overprovisioning isn't simplifying anything for the lamen, it's just misinforming them -- saying that Windows and drive manufacturers use different units would be simplifying it. 

 

 

@LinusTech @nicklmg

[Shimejii]

I also noticed this, im suprised Linus didnt point this out. Id assume he would know that, but apparently it went over his head. They are two different values, GB and GiBi.

 

 

[KenjiUmino]

now i have a question: if the "odd" numbers (60gb instead of 64, 120gb instead of 128 and so on)  come from factory applied overprovisioning (= making that last 4 or 8 gb not show up to the OS?) does that mean that a drive wich has 64 or 128 gb capacity accessible to the OS (minus formatting overhead and stuff) does NOT have this factory applied overprovisioning? 

[Enderman]

6 minutes ago, KenjiUmino said:

now i have a question: if the "odd" numbers (60gb instead of 64, 120gb instead of 128 and so on)  come from factory applied overprovisioning (= making that last 4 or 8 gb not show up to the OS?) does that mean that a drive wich has 64 or 128 gb capacity accessible to the OS (minus formatting overhead and stuff) does NOT have this factory applied overprovisioning? 

The odd numbers are what is shown in windows.

64GB is 60GiB

128GB is 120GiB

The 4 or 8GB ARE showing up to the OS, it's just that windows file explorer displays the storage in different units, GiB instead of GB.

When you go into the properties and see the big number that says "128,532,234,239 bytes" or whatever, that is the value in actual gigabytes (128GB).

 

The confusing thing is that windows and software like Magician show GiB as "GB" and then everyone thinks there is less storage than there actually is.

 

[KenjiUmino]

26 minutes ago, Enderman said:

The 4 or 8GB ARE showing up to the OS it's just that windows file explorer displays the storage in different units, GiB instead of GB.

that is not what i mean.  i know that windows does that. windows also may add a partition or two by default that are not seen in file explorer so the space shown as available after formatting is even less. does not matter. 

 

what i mean is this: i bought a 120gb SSD, that's what it says on the store page, thats what it says on the box and the sticker on the drive. BIOS also detects it as a 120gb drive so that is what i have to play with and the OS does whatever the OS does.

 

if i buy another SSD that says 128gb on the store page, box, sticker and BIOS also detects 128gb - does this drive have factory applied overprovisioning or not?

 

 

[79wjd]

7 minutes ago, KenjiUmino said:

if i buy another SSD that says 128gb on the store page, box, sticker and BIOS also detects 128gb - does this drive have factory applied overprovisioning or not?

Yes. All SSDs have overprovisioning -- they have extra NAND chips which makes the physical NAND total capacity >128GB.

[KenjiUmino]

5 minutes ago, djdwosk97 said:

Yes. All SSDs have overprovisioning. 

mkay, that's good to hear.

 

so next time i will be getting a 128gb for my boot drive. i have been fine with 120gb so far and i don't want to go the extra mile for a 240+ gb SSD because i don't feel like i need it any time soon. 

 

... but another 8gb on top for little to no extra money won't hurt.

[Enderman]

2 hours ago, KenjiUmino said:

that is not what i mean.  i know that windows does that. windows also may add a partition or two by default that are not seen in file explorer so the space shown as available after formatting is even less. does not matter. 

 

what i mean is this: i bought a 120gb SSD, that's what it says on the store page, thats what it says on the box and the sticker on the drive. BIOS also detects it as a 120gb drive so that is what i have to play with and the OS does whatever the OS does.

 

if i buy another SSD that says 128gb on the store page, box, sticker and BIOS also detects 128gb - does this drive have factory applied overprovisioning or not?

They should all have additional chips on them that are used for overprovisioning, however this extra storage space is only visible to the drive itself and not to the OS or BIOS.

 

You still should not fill an SSD over 90% because TRIM requires some free space to work, and the overprovisioned space is used for when nand chips run out of writes, not for garbage collection and other maintenance functions.

This is why an SSD will severely slow down when it fills up too much, regardless of how much extra nand it has from the factory.

[KenjiUmino]

2 hours ago, Enderman said:

the overprovisioned space is used for when nand chips run out of writes, not for garbage collection and other maintenance functions.

ok, so the overprovisioned space is ONLY there to take over when a cell from the usable area has died out and does NOT get touched at all to do anything else?

 

that means in the end i still have to make sure that the space i can use does not get filled up completely so all the maintenance functions can still work as intended.

 

now i could partition the drive so that a certain amount is left unnassigned to make absolutely sure i never fill up the drive completely, but what if i DO make a partition, format it and use it exclusively for the pagefile (linux creates this "swap partition" by default, why not do the same on windows?) 

 

my system with 16gb RAM should very rarely need to write to the pagefile so this would in theory be "unused space" (but not wasted space because it CAN be used if needed) and therefore have about the same effect as simply leaving that spot unallocated - right?

[Enderman]

28 minutes ago, KenjiUmino said:

ok, so the overprovisioned space is ONLY there to take over when a cell from the usable area has died out and does NOT get touched at all to do anything else?

 

that means in the end i still have to make sure that the space i can use does not get filled up completely so all the maintenance functions can still work as intended.

Yes.

 

I'm not sure if an SSD's garbage collection algorithms will use unallocated drive space if the partition it is cleaning is full, you might want to research that.

Don't mess with the windows page file stuff, just install windows and leave it as it is, otherwise sometimes it will screw itself up during updates or whatnot.

[woowee]

Does partitioning matter?  Drives don't see the file system so I doubt it, I just tend to keep 100GB empty to really give it extra space to work.  compact lzx is your friend!

 

As for over provisioning, they are probably cheaping out on that area on budget drives now.

[TommyTwommy]

I have a 250GB SSD and one max size partition.. it is showing me 232GB (249,XXX,XXX,XXX bytes)

[Enderman]

3 hours ago, berny22 said:

I have a 250GB SSD and one max size partition.. it is showing me 232GB (249,XXX,XXX,XXX bytes)

232GiB, 249GB

 

It's probably something like 249,5xx,xxx,xxx bytes because manufacturers round to the nearest gigabyte.

So yes it does have 250GB.