New SSD missing 200GB

[Deni_I]

I know that when you buy a new storage some of the space will be missing due to drivers or what not. I just bought nvme SSD from samsung, more specificaly Samsung 990 pro. For some unknown reason to me I only have 1,81TB storage available out of 2TB. I think that 200GB missing is unusualy large. Is it ok ? 

[TatamiMatt]

2 minutes ago, Deni_I said:

I know that when you buy a new storage some of the space will be missing due to drivers or what not. I just bought nvme SSD from samsung, more specificaly Samsung 990 pro. For some unknown reason to me I only have 1,81TB storage available out of 2TB. I think that 200GB missing is unusualy large. Is it ok ? 

Check the partitions and see if there are more than one

[Levent]

It’s designed that way.

https://youtu.be/M04JlWTRQEA?si=MehlqFpYqM2x47sK

[johnt]

Yes that is normal for 2 TB rated drives to have 1.8 TB of useable space. I have two in my NAS and that's how much capacity I have. Neither is a boot drive, which would reduce the useable space even more.

[Shimejii]

10 minutes ago, Deni_I said:

I know that when you buy a new storage some of the space will be missing due to drivers or what not. I just bought nvme SSD from samsung, more specificaly Samsung 990 pro. For some unknown reason to me I only have 1,81TB storage available out of 2TB. I think that 200GB missing is unusualy large. Is it ok ? 

Terabyte vs tibibytes.  Thats whats happening here.

[MiszS]

That's because windows uses the TB shortcut (terabyte, 10^12), but display the number in TiBi bytes, which are 2^40 > 10^12

[will0hlep]

1 hour ago, Deni_I said:

For some unknown reason to me I only have 1,81TB storage available out of 2TB.

I didn't feel any of the above explainations were complete, so I'm adding this:

 

When a manufacture makes a HDD or SSD they measure its capacity in Terabytes (TB), but Windows measures drive capacity in Tibibytes (This is usually written TiB, but for some reason windows writes it as TB which is why there is always confusion on this topic).

 

The difference between Terabytes and Tibibytes is they use different prefix systems.

 

Prefixs like Kilo, Mega, Giga and Tera are Decimal prefixs and therefore you multiply or divide by 1000 to move between them, so 1000 Bytes is a KB, 1000KB is a MB and so on.

However, Prefixs like Kibi, Mebi, Gibi and Tebi are Binary prefixs and therefore you multiply or divide by 2^10 (or 1024) to move between them, so 1024 Bytes is a KiB, 1024KiB is a MiB and so on.

 

Because of this a TB is 1,000,000,000,000 Bytes while a TiB is 1,099,511,627,776 Bytes (almost 10% larger).

 

The effects that the above has are as follows:
Here is the capacity information of the WD SN740 SSD in my laptop.

In total it stores 2,047,720,046,592 Bytes which is actually about 2% more than the 2TB (2*1000^4 or 2,000,000,000,000 Bytes) the drive manufacture said the drive would have. However, windows measures the drive in Tibibytes and 2TiB would be 2*1024^4 or 2,199,023,255,552 Bytes. Clearly while the drive has more than 2TB, it has less than 2TiB. To get the 1.86 figure, Windows does 2,047,720,046,592 divided by 1024^4 which gets 1.86(23.....) TiB.

[mariushm]

Windows uses multiples of 1024 when it shows file sizes, disk space, everything.

 

It's a historical thing, from the MS-DOS days and 8086 processors, because back then it was much much easier and faster for processors to divide numbers that are multiples of 2 so dividing by 1024 (which is 2¹⁰ ) is much faster than dividing by 1000.

 

Let me give you an example: 

Let's say you have a file size in bytes - 45217 bytes - and you want to display in KB.  

 

This value 45217 in binary is 1011 0000 1010 0001  

 

If you want to divide numbers by 2, you can simply delete the last bit, so for example by deleting the last 1, you get 1011 0000 1010 0001  which is 22608 in decimal, or basically 45217 / 2, rounded down. 

 

If you want to divide by 1024, you simply remove the last 10 bits, because 1024 is 2¹⁰  so the binary number becomes 1011 0000 1010 0001 and that 101100 in binary is 44 in decimal,  so you got 44 KB, which is close enough to 45.2 KiB to not matter that much. 

 

If you were to divide by 1000, you would have to divide by 8, and then you'd have to divide by 125 ... so a lot more cpu cycles would be wasted .. when your processor was running at 4-8 MHz, the difference between  4 cpu cycles and 200-300 cpu cycles to computer one result makes a huge difference. 

 

For the same reason, file systems like FAT and FAT32 by default arrange the drive in 512 byte sectors, because 512 is 2⁹ and ba sector was considered the minimum disk space you can reserve, by arranging the millions of bytes in sectors the file system could easily count how many free sectors are available and where empty space is available to put new files.

So even if you created a text file with just a few characters, on disk 512 bytes were permanently assigned to that text file.

 

 

Hard drives were always sold using capacity as millions or billions of bytes, even when you bought a hard drive advertised as 2.1 GB or 4.3 GB, on the drive you would actually read that the drive has at least 2.1 or 4.3 billions of bytes.

 

SSDs kept this method of expressing sizes even though they don't have to, because it gives them the ability to hide a portion of the Flash memory and use that hidden portion as spares (to extend the life of the drive) or to store information about the data stored in the flash memory chips the controller can use for internal things. 

 

Flash memory chips are actually manufactured using multiples of 8 and 1024, so for example a 2 TB SSD would be made with 2  1024 GB Flash memory chips for a total of 2048 GB, where each GB is 1024 MB, where each MB is 1024 x 1024 bytes,or around : 2 x 1024 x 1024 x 1024 x 1024 = 2,199,023,255,552 bytes

 

but the SSD manufacturer will sell it to you as 2,000,000,000,000  bytes or 1907 GB (if you use multiples of 1024) or 1.86 TB (again, using multiples of 1024). When you format the partition, a bit of space is used by the file system, so that would explain why you see 1.83 TB at the end. Or, there may be a small 500 MB - 1 GB recovery partition besides your main big partition created on the drive. 

 

 

[Needfuldoer]

It's the difference between terabytes (base 10 that people use) and tebibytes (base 2 that computers use).

 

2 TB = 1.8 TiB.

 

 

[johnt]

6 hours ago, will0hlep said:

I didn't feel any of the above explainations were complete, so I'm adding this:

He didn't ask for an explanation.

[will0hlep]

2 hours ago, johnt said:

They didn't ask for an explanation.

Your right, they didn't ask for an explanation. not directly atleast. But that doesn't mean they weren't after one or that one shouldn't be put here for the benefit of others.

 

2 hours ago, johnt said:

They didn't ask for an explanation.

On another topic, did my orginal post upset you in some way? I might be misreading this (tone is difficult in text), but "They didn't ask for an explanation." seems like a strange thing for someone to write on here. If you were upset by my orginal post, (firstly sorry, and secondly) please know I was not trying to be critical of your post (or the other posts in this thread). You and several others had adequately addressed the question that was asked. I was just looking to clearly dispense information that I felt might be of use to the OP and other readers.

 

I hope you have a good day

[johnt]

26 minutes ago, will0hlep said:

I hope you have a good day

Hope you do too!  No offense taken from your excellent post. Sometimes folks aren't interested in that much info and they are just making sure nothing is broken. But there ain't nothing wrong with sharing the information for the edification of everyone reading it.