SSD Storage Size: Does Apple cheat?

[Yahooligan]

Maybe I need to clarify. Mac OS X is actually calculation 1 KB = 1000 B (not 1024) which is already the "cheaty way of calculating". It shows the full number (without any /1024 oder /1000) as 499,xxx,xxx,xxx,xxx BYTES!

So I can say: it is not the typical 1000/1024 issue which would normally lead to the case that you buy a 1 TB drive (1000,xxx,xxx,xxx,xxx Bytes, Windows calculates /1024 and says 930 GB).

What I dont understand is why it is actually less than the cheaty way of 512 GB, reported in the hardware tool which SHOULD include the space used by filesystem meta and recovery partition.

Apple clearly states...

1GB = 1 billion bytes and 1TB = 1 trillion bytes; actual formatted capacity less.

Do the math. Not to mention filesystem overhead, recovery partition, etc like has already been said.

Nobody is lying or cheating, you just have been living under a rock I guess.

 

[old-wiz]

It's hard to believe we are stil having this argument. There have been so many threads ever since I joined this forum, and all have argued the same thing from both sides. jeez.

 

[john123]

It's hard to believe we are stil having this argument. There have been so many threads ever since I joined this forum, and all have argued the same thing from both sides. jeez.

I agree. #firstworldproblems. I swear, people will complain about just about anything.

 

[adnbek]

We also mentioned the recovery partition which will be at least the size of OS X which is I think 8GB.

The recovery partition is not 8gb. It doesn't hold the entire OS, just the minimum required to boot and take you to the recovery screen (plus some apps). All in all, it's about 650mb in size.

 

[-Eden]

What's next? "Oh I have 7.9gb of RAM instead of 8.00?????"......

 

[durkkin]

As you can see, there is 499 GB in the 1000 byte = 1 kilobyte "cheated counting way". In the old style counting way it would be even less: 464.80 GB ( 1024er counting).

It is actually not cheating. Apple does put the disclaimer on their website that 1 GB is 1,000,000,000 bytes, but also, that is how it's defined. The actual name for the binary version, in which 1 GB is 1024 MB is gibibyte. This naming difference is to preserve the meaning of the actual Greeks roots and at the same time be able to differentiate the decimal and binary systems.

I'm sure somewhere along the line it the physical size of HDD platters and the bits themselves came into play. It is tricky, but the manufacturers are staying honest while simultaneously advertising "more" space and playing off the binary mindset of consumers when it comes to computers.

As for you "missing" storage, as others have said it relates to formatting, the file system itself, your recovery partition, EFI boot partition, amongst some other things.

 

[akramer]

This has nothing to do with whether you count a gigabyte as 2^30 or as 1e9 bytes. This has nothing to do with preinstalled applications, or the size of the OS, the EFI partition, or the restore partition. Stop saying that, it's wrong.

A hard drive manufacturer's 512GB will be 512,000,000,000 bytes.
An actual 512GB (now written as 512GiB or gibibytes due to hard drive marketing people) is 549,755,813,888 bytes.

You'll notice that neither of those is the size of the addressable space of the SSD sold as a 512GB drive by Apple.

Spinning hard drives have spare sectors that are used to remap bad sectors. These were not factored into the size of a hard drive. SSDs require a much larger amount of spare space to function properly, and some manufacturers started listing this unaddressable space as if it were part of the usable capacity. Not all manufacturers do this, but Apple is among them.

https://support.apple.com/kb/TS2419 describes that this is expected behavior, and the "missing" space is used for wear leveling, write buffering, and spare blocks.

Image attached to show that the unformatted capacity is not 512GB by any measurement, even when taking the EFI and recovery partitions into account.

 

[Jah2013]

This has nothing to do with whether you count a gigabyte as 2^30 or as 1e9 bytes. This has nothing to do with preinstalled applications, or the size of the OS, the EFI partition, or the restore partition. Stop saying that, it's wrong.

A hard drive manufacturer's 512GB will be 512,000,000,000 bytes.
An actual 512GB (now written as 512GiB or gibibytes due to hard drive marketing people) is 549,755,813,888 bytes.

You'll notice that neither of those is the size of the addressable space of the SSD sold as a 512GB drive by Apple.

Spinning hard drives have spare sectors that are used to remap bad sectors. These were not factored into the size of a hard drive. SSDs require a much larger amount of spare space to function properly, and some manufacturers started listing this unaddressable space as if it were part of the usable capacity. Not all manufacturers do this, but Apple is among them.

https://support.apple.com/kb/TS2419 describes that this is expected behavior, and the "missing" space is used for wear leveling, write buffering, and spare blocks.

Image attached to show that the unformatted capacity is not 512GB by any measurement, even when taking the EFI and recovery partitions into account.

Thank you. It's still weird that apple wouldnt just let it say 512,... bytes and say Macintosh HD got a size of 499,...,...,... bytes.

 

[robjh]

I inspected the disk in my mbpr using gparted.

excuse the fact this is a photo instead of a screenshot, the livecd didnt have the right wireless driver.
http://robjh.com/perm/apple/mbpr_2013_disk_architecture.jpg

I have shrunk the main partiton, hence the vast amount of empty space.

It looks like the drive has 500gb of decimal space avalible with 200mb used as a boot partition and 800mb used as a recovery partition.
the remaining 499gb (decimal) is used as the system partition, which is what others have reported here.

 

[thundersteele]

My 256 GB Samsung 830 SSD reports 256.06 GB (256,060,514,304 bytes) in OSX. About 1 GB is used up by the EFI and recovery partitions, so my system partition is 255 GB.

My original 128 GB Apple SSD had reported something like 120 GB (i.e. 120,000,000,000 bytes) space. This is almost 7% below the advertised storage capacity, and in my opinion questionable business practice.

The 512 GB SSDs that end up having 500 GB capacity are lacking about 2.3% of the advertised storage space. This is probably acceptable, but one still wonders why they don't just advertise it as 500 GB.

It is actually a difficult question what should be included in the advertised "disc space." I feel that it is wrong to include the spare space that is not actually addressable. On the other hand I agree that space taken by recovery partitions or by the system installation should be considered part of the "disc space", although it is not part of the actually usable space.
Maybe a fair option would be for Apple to list the "user available space" out of the box, i.e. say that if you go for the 256 GB SSD, when you boot up the first time you will have at least 240 GB of free space.


Apart from all the above, there is of course the GB vs. GiB issue. As long as this is clearly spelled out, I don't mind. On the other hand, you look at the online shop and you see:
8 GB memory
256 GB flash storage (1)
I can see how this is very misleading for people that are inexperienced in the PC business. That footnote explaining the GB = 1 billion bytes is also not so easy to find.

 

[Yahooligan]

That's strange, because the Samsung drives allocate 5-10% for overprovisioning, at least the newer 840 Pro drives do.

In any event, it's not Apple being sneaky. This is the common way drive capacity is shown, it's been this way for a long time, and the reason why Apple and others state that 1GB = 1 billion bytes is because people weren't aware of this standard for storage and they complained/sued, so now there is a disclaimer shown.

 

[Sym0]

Hey there,

I would like to know what you guys think about the reported storage size in system report... I ordered an "512GB model" but this is what it reports:

499,08 GB (499.082.485.760 Byte)

As you can see, there is 499 GB in the 1000 byte = 1 kilobyte "cheated counting way". In the old style counting way it would be even less: 464.80 GB ( 1024er counting).

I am missing 12 GB's. Where is it ? Is is just deactivated for wear leveling ? To check yourself, go to -> About this mac -> More information -> System report -> Storage

Wait till you find our about cluster sizes, so that every piece of data written takes up a fixed amount of minimum space. A 1GB file will take up 1GB, but 100,000 small files with a total of 1GB will take up 100GB LOL.

 

[alphaod]

My 256 GB Samsung 830 SSD reports 256.06 GB (256,060,514,304 bytes) in OSX. About 1 GB is used up by the EFI and recovery partitions, so my system partition is 255 GB.

My original 128 GB Apple SSD had reported something like 120 GB (i.e. 120,000,000,000 bytes) space. This is almost 7% below the advertised storage capacity, and in my opinion questionable business practice.

The 512 GB SSDs that end up having 500 GB capacity are lacking about 2.3% of the advertised storage space. This is probably acceptable, but one still wonders why they don't just advertise it as 500 GB.

It is actually a difficult question what should be included in the advertised "disc space." I feel that it is wrong to include the spare space that is not actually addressable. On the other hand I agree that space taken by recovery partitions or by the system installation should be considered part of the "disc space", although it is not part of the actually usable space.
Maybe a fair option would be for Apple to list the "user available space" out of the box, i.e. say that if you go for the 256 GB SSD, when you boot up the first time you will have at least 240 GB of free space.


Apart from all the above, there is of course the GB vs. GiB issue. As long as this is clearly spelled out, I don't mind. On the other hand, you look at the online shop and you see:
8 GB memory
256 GB flash storage (1)
I can see how this is very misleading for people that are inexperienced in the PC business. That footnote explaining the GB = 1 billion bytes is also not so easy to find.

Sounds like the Samsung is allocating no space to over-provisioning? I think the amount can be changed in their Magician software, or they never designed the 830 with Macs in mind.

 

[thundersteele]

That's strange, because the Samsung drives allocate 5-10% for overprovisioning, at least the newer 840 Pro drives do.

Sounds like the Samsung is allocating no space to over-provisioning? I think the amount can be changed in their Magician software, or they never designed the 830 with Macs in mind.

Hmm, this is strange. Does this mean my SSD was for some reason set up with zero over-provisioning? Will this hurt performance and/or data safety?

Well at least it is nice to see that the 256 GB are actually there.

In the end manufacturers have to decide whether they want their customers feel cheated out of storage space. It would not be so difficult to mention the actual available space. Although I think this is more relevant for tablets and phones, where (a) customers are (on average) less tech savvy and (b) it actually matters if your 64 GB tablet only has 28 GB available storage (MS Surface ).

 

[Yahooligan]

Hmm, this is strange. Does this mean my SSD was for some reason set up with zero over-provisioning? Will this hurt performance and/or data safety?

Theoretically, both. Over provisioning is there for garbage collection and endurance, so without having any space set aside for over provisioning you may not be getting the most out of your SSD. I'd at least look into it for your SSD.

 

[Weaselboy]

Hmm, this is strange. Does this mean my SSD was for some reason set up with zero over-provisioning? Will this hurt performance and/or data safety?

No. Your Samsung 830 comes with about 7% over provisioning already set. The Magician utility just allows one to increase the amount if you like. You don't need to do anything.

There is a white paper here from Samsung on the topic.

 

[thundersteele]

No. Your Samsung 830 comes with about 7% over provisioning already set. The Magician utility just allows one to increase the amount if you like. You don't need to do anything.

There is a white paper here from Samsung on the topic.

Thanks, this helps. However note that I have a 830 series SSD, and the white paper states that
"Historically, Samsung has not implemented mandatory OP on any of its SSDs. With the introduction of the 840 Series and the reality of increasingly complex NAND fabrication processes, however, Samsung has chosen to implement a minimum amount of OP in its mainstream drives (the 840 PRO will not feature mandatory OP)."

So I guess I have zero OP. The way I understand the paper I should be fine as long as I keep ~10% free space, but performance might not be optimal.

 

[Weaselboy]

Thanks, this helps. However note that I have a 830 series SSD, and the white paper states that
"Historically, Samsung has not implemented mandatory OP on any of its SSDs. With the introduction of the 840 Series and the reality of increasingly complex NAND fabrication processes, however, Samsung has chosen to implement a minimum amount of OP in its mainstream drives (the 840 PRO will not feature mandatory OP)."

Yeah... I saw that too, and it is confusing. Before I posted I Googled around a bit and saw several forum posts from Windows users saying they could see the ~7% unused space. So who knows.

So I guess I have zero OP. The way I understand the paper I should be fine as long as I keep ~10% free space, but performance might not be optimal.

Exactly. Unless you are running your drive near full, it is not an issue.