What is the maximum single hard drive capacity windows 10 supports?

[sonyzz]

I would like to replace my 12tb wd gold (and later 2 x 14tb wd gold) drive to 20tb wd ultrastar 'DC HC560' model drives because price is very affordable https://www.scan.co.uk/products/20tb-western-digital-ultrastar-hc560-sata-hard-drive-35-hdd-sata-6gb-s-7200rpm-512mb-cache-512e-4096  (I paid same price for 14tb drive back in 2020 July) and I've read that new wd gold drives are mostly rebadged wd ultrastar drives with modified firmware but same hardware (my 14tb wd gold drives which are newer say 'powered by ultrastar' and have a different label than 12tb gold drive before wd merged ultrastar line and gold). As I started doing a bit of research on those drives and compatibility of them inside pc - I found conflicting answers online... Some websites say that windows support maximum of 16tb drives, others say that GPT partition supports up to 9 exabytes... Which would be the correct answer?

[Oshino Shinobu]

18 exabytes. Windows itself has no limit on capacity AFAIK, it's entirely down the the partition table and GPT caps out at 18 exabytes. 

 

https://docs.microsoft.com/en-gb/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-10

 

EDIT: I believe that's also per partition. It might be possible to have a single drive exceeding that but with multiple partitions. GPT allows up to 128 partitions, so theoretically a maximum capacity of 2,304 exabytes (2.3 Zettabytes). 

[Eigenvektor]

18 minutes ago, sonyzz said:

Some websites say that windows support maximum of 16tb drives, others say that GPT partition supports up to 9 exabytes... Which would be the correct answer?

The 16 TB limit applies when you use MBR (which you shouldn't with Windows 10). So both answers are correct in their respective context.

https://www.alphr.com/mbr-vs-gpt/

 

In other words use GPT and the limit is no issue for the foreseeable future.

[Oshino Shinobu]

15 minutes ago, Eigenvektor said:

The 16 TB limit applies when you use MBR (which you shouldn't with Windows 10). So both answers are correct in their respective context.

https://www.alphr.com/mbr-vs-gpt/

 

In other words use GPT and the limit is no issue for the foreseeable future.

*MBR can't go to 16TB. There's a 2TB limit for MBR, even across multiple partitions it cannot use more than 2TB of capacity. 

 

EDIT: In general at least. If the sector size is 4096 then 16TB is the max, but majority are 512. 

[sonyzz]

4 minutes ago, Oshino Shinobu said:

*MBR can't go to 16TB. There's a 2TB limit for MBR, even across multiple partitions it cannot use more than 2TB of capacity. 

 

EDIT: In general at least. If the sector size is 4096 then 16TB is the max, but majority are 512. 

I'm using GPT for all the drives. WD gold 14tb is only 512e, wd gold 12tb with 'AF' written on it is 512e/4Kn, that ultrastar drive specs sheet says 512e/4Kn at first I was confused that it might not work but, if my 12tb one works just fine - I have nothing to worry then.

[Oshino Shinobu]

1 minute ago, sonyzz said:

I'm using GPT for all the drives. WD gold 14tb is only 512e, wd gold 12tb with 'AF' written on it is 512e/4Kn, that ultrastar drive specs sheet says 512e/4Kn at first I was confused that it might not work but, if my 12tb one works just fine - I have nothing to worry then.

Yeah it'll be fine. We're no where close to reaching the limits of hard drive capacities supported by GPT. 

[sonyzz]

29 minutes ago, Oshino Shinobu said:

18 exabytes. Windows itself has no limit on capacity AFAIK, it's entirely down the the partition table and GPT caps out at 18 exabytes. 

 

https://docs.microsoft.com/en-gb/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-10

 

EDIT: I believe that's also per partition. It might be possible to have a single drive exceeding that but with multiple partitions. GPT allows up to 128 partitions, so theoretically a maximum capacity of 2,304 exabytes (2.3 Zettabytes). 

That means 20tb drive will work as single partition with 18.5TB of usable space (or something like that)?

[sonyzz]

2 minutes ago, Oshino Shinobu said:

Yeah it'll be fine. We're no where close to reaching the limits of hard drive capacities supported by GPT. 

 

24 minutes ago, Eigenvektor said:

The 16 TB limit applies when you use MBR (which you shouldn't with Windows 10). So both answers are correct in their respective context.

https://www.alphr.com/mbr-vs-gpt/

 

In other words use GPT and the limit is no issue for the foreseeable future.

Thank you guys, appreciate the answers

[mariushm]

He's saying EXA bytes ... there's terabytes (TB) , petabytes, exabytes, zettabytes, yottabytes ...

 

Basically, as long as you use GPT, there's no reason to worry about maximum hard drive sizes... you're nowhere close to a limitation.

 

[Oshino Shinobu]

4 minutes ago, sonyzz said:

That means 20tb drive will work as single partition with 18.5TB of usable space (or something like that)?

Should be about 18.19TiB.

 

The reason for the seeming missing space is just due to Windows mixing its units. It shows capacity in binary units (Mebibytes, Gibibytes, Tebibytes) but uses the acronyms for decimal units (MB, GB, TB) when it should be using the binary ones (MiB, GiB, TiB). 20TB (Terabytes) is 18.189TiB (Tebibytes). Drives are quoted by manufacturers in decimal units, so a lot of people mistakenly believe that it's just down to overhead or manufacturing tolerances, but it's just due to unit conversion.  

[mariushm]

TLDR  ... 

 

20 TB  =  20 x 1000 GB  =  20 x 1000 x  1000 MB  =  20 x 1,000 x 1,000 x 1,000,000 bytes

 

Windows uses multiples of 1024 :   1 KiB = 1024 bytes,  1 MiB = 1024 x 1024 = 1,048,576  bytes and so on... 

 

SO  20,000,000,000,000  / 1,048,576 = 19,073,486.328125 MIB  / 1024 = 18,626.4514 GiB   / 1024 =   18.189 TB