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Sandisk Memory Stick Pro Duo 512Mb only 468Mb |
P800!
Joined: Jan 25, 2004
Posts: 84
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Why is the capacity of my flash memory card (as reported by many operating systems) different that the capacity that is listed on its label?
Here is the answer:
The operating system, when reading the size of the card, reports a slightly (On a 512Mb they might have to redefine "slightly") different capacity than what is listed on the card's label
Solution:
Definitions of a Megabyte:
1) Operating Systems commonly define a Megabyte (MB) as: 2 to the 20th power (1,024KB--Kilobytes).
2) DiskDrive and Flash Memory Card Manufacturers commonly define a MB as one million bytes (exactly 1,000,000 bytes).
Unformatted (Capacity)
Also known as drive byte capacity before formatting. The Maximum capacity of disk drive before formatting equals
[ (# Cylinders) X (# Heads) X (# Sectors) X (# Bytes per Track) ]
Example:
64MB CompactFlash Card consists of:
490 Cylinders
8 Heads
32 Sectors
512 Bytes per Track
This equates to: [ (490) X (8) X (32) X (512) ] = 64,225,280
Unformatted Capacity: 64,225,280 bytes
Formatted Capacity: 63,934,464 bytes (User Data)
Cause:
Disk Drive Companies such as SanDisk define 1 MEGABYTE as 1,000,000 BYTES. Operating Systems define 1 MEGABYTE as 1,048,576 BYTES (1024K X 1024K or 2 to the 20th power).
Example:
SanDisk 64MB CompactFlash Card being read by Microsoft Operating System.
SanDisk Total Formatted Capacity divided by 1 MB (as defined by the Operating System) equates to the following:
63,934,464 BYTES / 1,048,576 BYTES = 60,972,656 BYTES, 60.9MB displayed by OS.
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I'll be back!
[ This Message was edited by: P800! on 2004-10-09 22:22 ]
[ This Message was edited by: masseur on 2004-10-11 10:50 ] |
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baseballfanz
Joined: Sep 21, 2004
Posts: > 500
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Yeah when I bought a brand new Sony 128mb duo, stick it in my p900 and with 0% used it shows only 124mb avaiable. Even internal memory don't add up to what manufactuer claims anyway. |
Jim
Joined: Jan 20, 2002
Posts: > 500
From: Belgium
PM |
It's like a pc harddrive ..... so such thing doesn't really bother me as I'm used to the fact that you will never have the total capacity as indicated and when I buy something I'm aware of it 
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nickorooster
Joined: Sep 28, 2004
Posts: > 500
From: UK (Originally NZ)
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Same here, Its not that they are cheating you, but that they are using "appropriate" language when selling their product. It's like CPUs, (Like Pentium etc) when they are made, they basically make a bunch, then test them as to what speed they can run safely, then "downgrade" them to the nearest level. eg, your pentium 4 2.0ghz may have been tested to perform at 2.1ghz stably, then set (via voltage and FSB) to run at only 2. When Overclockers overclock their machines, they may in fact only be increasing their processors to their rated value.
It's the same with hard-drives, cd's and RAM. The manufacturer makes them, then tests their capacity and rates them as so. (CD and RAM is more accurate, I could explain why, but it'd take too long).
So, all in all, I'm assuming it's the same with these memory sticks.
That's my 2 cents.
Nick
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mmsman
Joined: Dec 14, 2002
Posts: > 500
From: slovenia
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it's the same with all things, i'm suprised you did't know that  you hardl notice it on a 32 mb stick but wait till you get a 1gb one  and it's hardly cheating you, i mean it's the common pc language... |
P800!
Joined: Jan 25, 2004
Posts: 84
PM |
I knew about this, but it just posted it so that others might realise that you will lose 44Mb on a 512Mb Duo Pro. As was said, you don't notice it too much on a 32Mb Duo Pro, but it just got me for a moment when I put the 512Mb Duo Pro in my P910i.
Maybe they should have a "Real MB size" on the packaging, or add some memory in to bring it up to the 512Mb quoted, it wouldn't cost that much.
I'll be back!
(P800! because I can't change username to P910i!) |
daeid
Joined: Jan 06, 2004
Posts: 30
PM |
i dont know how people can complain continually about this, the simple fact is drive manufacturers display size in millions of bytes which is still MB in their abbreviation, and fairly enough. it is how they calculate the size.. you still have as much space as you paid for, however the way it is advertised can be misleading to someone who doesn't know that a 320GB hard drive will only have 298GB...
dave |
nickorooster
Joined: Sep 28, 2004
Posts: > 500
From: UK (Originally NZ)
PM |
Why not? Its not like Sandisk cant afford to, even if they have to raise the price by a few quid, most will be happy they are getting what they thought they were originally... And on the topic of packaging, my HD does have the actuall size written on it, 74Gb, so its not like its big secret or anything.
BTW I know that you know what you're talking about, because you explained it so well in your first post, and I agree, peope should know what they are buying. What if they have a file that is 500mb large? Too bad....
Nick
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irfan
Joined: Jul 31, 2004
Posts: 238
From: glasgow
PM |
so what is the actual mb on a sony 512. It would help to know if we did the maths with the price whether the so called cheaper stick is actually cheaper? Especially when it comes round to buying the 1gb stick |
jplacson
Joined: Apr 21, 2002
Posts: > 500
From: Philippines
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Things are the same with cars as well... the displacement that they stamp on the car is usually rounded up to the nearest higher value.
a 2.0L engine is usually something like 1,925 cc
Psychologically, placing 498.56MB doesn't look or sound as good as 512. And saying I've got a 1.925L engine doesn't sound as good as saying 2L.
It's all marketing.
Computer manufacturers aren't the only ones doing it.
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remiavan
Joined: Sep 19, 2004
Posts: 66
PM |
yeah when i got a 128 meg memory stick it was actually 123 i was thinkin of formating it again to see if it'll increase but i bet thats a waste lets calculate this 128*4=512 so if in my xperience i lost 5 megs multiplying that by 4 we get 20 megs so in a 512 meg memory stick the memory there shul be 492 hmmm now thats a rip off therefore buying 4 128 meg memorystick is even better
SE'Z RULE NOKIAZ DROOL |
Residentevil
Joined: Feb 29, 2004
Posts: > 500
From: Raccoon City, USA
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I got a movie 126Mb and wanted it to put on a 128mb duo, but it only has 123.5
Tough times don't last, tough people do!
Free Tibet |
DeLa
Joined: Jan 22, 2003
Posts: > 500
From:
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The capacity of media is always displayed 'before formatting'. Formatting itself always reduces the available space. Because the formatting is done by an operating system the final result can vary across the operating systems. Therefore it is 'justified' to announce the physical memory space.
It has always been like that. Remember the floppy disks. A disk formatted vor DOS lost more space then one formatted for Apple.
So I wouldn't know why Sony should be the first to displat the amount of memory after formatting. |
P800!
Joined: Jan 25, 2004
Posts: 84
PM |
My only gripe (and it is a big one) is that on small memory card of 512 Mb, a loss of 44 Mb is bloody significant. On a hard drive (lets say 120 GB), if I end up with 114 GB it is not such a problem, as if I wanted more space I would just pay a few pound extra to get a larger drive in the first place.
This is not so easy to do with memory cards. Firstly they have not released the 1 GB version yet, and secondly it will not just cost a few pounds more to get this card.
I rest my case!
I'll be back!
(P800! because I can't change username to P910i!) |
jplacson
Joined: Apr 21, 2002
Posts: > 500
From: Philippines
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Well, even SD, MMC, and CF cards do this as well. It wasn't started by Sony.
And if you read the packaging on all memory products, it DOES state the actual numbers on the packaging (at least my MS Duo did)
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Posted: 2004-10-09 23:11
