USB drive size limitation.

Hi!
I Have two 640Gb notebook HD that I was about to use as backup. One Western Digital Scorpio blue and one Toshiba.
When I use then in OSX, the SO can address all the 640GB available.
When I try to use the in Win 7, it only sees 596,17, no matter what case or drive I use.
Both of drives are not partitionated or formatted

Any ideas of what is going on?
Thanks!

 

1024^3 vs 1000^3

Microsoft seems to be the only one in town to use 1024^3 as GB

 

Yup, this is definitely that issue again. The drive is fine.

 

Sorry, Im a kinda noob.
So there is nothing to do? Just lost 40GB in Windows?


Thanks for the quick answers

 

You never lose anything. What you have purchased is 640*1000*1000*1000 bytes disk.

What Windows show you is 640*1000*1000*1000 / (1024*1024*1024).

 

Windows and Mac OS/Linux calculate file size differently. There's the exact same amount of space on the drive in both OSes. Windows is just dumb (or technically correct) depending on who you ask.

 

Windows is, in fact, technically correct as stated earlier. Most HDD boxes have a note (disclaimer) about this very subject. You still have 640 gee bees, the Os'es just calc differently.
640,000,000,000(640Gb)/1024/1024/1024=596Gb-thats Windows and technically correct since 1024 Mb=1 Gb.
640,000,000,000/1000/1000/1000=640Gb-Mac OS

 

Actually Windows is technically incorrect, they should be stating Gibibytes (GiB) when using that method of calculation

 

He???

10^15 -> I think Peta
10^12 Terra T
10^9 Giga G
10^6 Mega M
10^3 Kilo k

-> That "G" comes from good old maths, which gets it from I think greek.

 

IEC vs. SI units.
Gigabyte - Wikipedia, the free encyclopedia
Byte - Wikipedia, the free encyclopedia

Michael

 

I guess some paper pusher just wants to make people's lives difficult...

 

OS X started doing this recently with Snow Leopard. If you search for reviews of the OS you'll see people saying how they gained 40GB of space after installing snow leopard. What Apple did was change their scales.

Before it was 1024MB = 1GB
Now it is 1000MB = 1GB

HDD manufacturers state 1000MB = 1GB also so when you buy a HDD at 640GB it's just 640,000MB. Divide it by the OS X way you'll get 640GB, Divided by the other way and you'll obviously get less than that. This is why you'll see the disclaimer on HDD packages saying:

 

^^^Exactly!!!

 

no, as harddrive manufacturers continued to sell drives with more off numbers, people realised that it has to be fixed if you count in decimal (1000) or in binary (1024), and had to differenciate. afaik linux follows the rules quite strict, microsoft has the wrong naming.

the hdd manufacturers can cheat you with 100gb on a 1tb disk. that's 10% on the package that you can't save. my home server is right now 1x1tb and 3x2tb. yet i can't save 7tb worth of data on it, but only 6.37tb.

i intentionally did not write the different conventions here btw.

the conventions with gibi and giga, tebi and tera are there for that 10% difference that exists nowadays.

 

-> only it results in more names to remember....

Considering that computers work in a system 2^something it's rather the HDD manufacturers that I'd complain about.
On that note - interesting that HDD manufacturers use a decimal system when the prevalent operating system uses a 2^something system.

 

I am not sure about HDD but there is a reason for SSD to be selling in the 1000^3 way in that the unexposed NAND becomes their buffer for wear leveling purpose. May be HDD also use that for its own BBR ? We all know that computer in general deals with things in 2^something.

 

It's possible, although I think that might be excessive. And unless I am mistaken the "spare space" the HDD has for reallocation isn't that large...

On that note - I don't think values like "Gi" exist in maths -> hence wrong

 

Gi is not a value, it's a prefix.
And mathematicians don't deal with prefixes usually.

Michael

 

That is true, although you will find that the prefixes are a part of math
At least you'll find them in a maths book of definitions unless I am mistaken.

And if we were to speak to a "normal human" we'd used the prefix Giga rather than 10^9
Or Kilo.
ould you buy 5*10^2 gram of coffee? I wouldn't. Or 10^3 gram of sugar?

 

Hehe, would be funny, indeed. But there are still regions on our planet, that can't even handle kilograms and meters and resort to ounces, pounds, fingers and feet

Using the energy equivalent of a given mass is even more funny btw.

Michael

 

I know... I'm currently living in such a region... on that note though, the only imperial measurement I "know" is miles - roughly 1,6km per mile - and that's not too accurate.

-> On that note though, the metric system was also brought about by "Imperialism" - by Napoleon to be exact.

 

well.. at least thanks to the definition one can now point out the wrongs. but yeah, at start everyone followed the 2^ system. then hdd manufacturers realized that they can save some money by moving to the 10^ system. wasn't that much of a problem for megabyte and even gigabyte drives. but, as said, for terabyte drives, it's a 10% cheat.

then again, there are lots of places where it's not that easy, too. networking for example. first, people don't get that transferring a 1GB File over a 1Gb/s network does not happen in one second, but 8 or 10. then they don't get, why 8, why 10.

but in the end, it means i have to buy 11 terabytes of storage to get an actual 10 terabyte pool in my winhome server (about 4gb more). happily, i don't care. I have DE => its all automatic (offtopic rant about vail).

the net result: it's a mess, and about no one cares.. there are annoying moments, though. like "how about using an ssd as system disk for my home server? i have a 64gb ssd lying around"
"oh no, windows needs a 60gb size as minimum, and my 64gb ssd formats as 59.6046448gb"

those are annoying moments

 

Wow! Thanks for all the answers!