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Home > Archive > Data Storage > February 2005 > Kingston "512MB" SD flash cards - only 488MB
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Kingston "512MB" SD flash cards - only 488MB
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I have three of these, all brand new. All show 488MB as the size when
formatting them and this is matched by the size of the files that can
be transferred to them from a PC.
Even allowing for 1k being 1024 etc this is a very big shortfall.
Is this normal? I haven't seen it on 128MB and 256MB SD cards.
They are used in PDAs to store GPS moving map data.
Peter.
--
Return address is invalid to help stop junk mail.
E-mail replies to peter1234@peter2000XY.co.uk but remove the X and the Y.
Please do NOT copy usenet posts to email - it is NOT necessary.
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| Alun Saunders 2005-02-04, 5:46 pm |
| Peter wrote:
> I have three of these, all brand new. All show 488MB as the size when
> formatting them and this is matched by the size of the files that can
> be transferred to them from a PC.
>
> Even allowing for 1k being 1024 etc this is a very big shortfall.
>
> Is this normal? I haven't seen it on 128MB and 256MB SD cards.
>
> They are used in PDAs to store GPS moving map data.
488*1024*1024=511705088 ... not far off 
It's the same with hard disks. Most manufacturers define a MByte as
having 1,000,000 bytes and most OS's define it (correctly) as
1024*1024=1048576 bytes. Plus you've got formatting overhead for
whatever file system you are using.
FWIW my el cheapo Lidl sourced 512MByte SD card gives a capacity of
513,015,808 bytes or 498MBytes formatted as FAT.
--
Alun Saunders
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| Alun Saunders 2005-02-04, 5:46 pm |
| Alun Saunders wrote:
> FWIW my el cheapo Lidl sourced 512MByte SD card gives a capacity of
> 513,015,808 bytes or 498MBytes formatted as FAT.
Sorry for the typo, that should read 489MBytes
--
Alun Saunders
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| Paul Rubin 2005-02-04, 5:46 pm |
| Peter <peter@no-spam-please-6644.co.uk> writes:
> Is this normal? I haven't seen it on 128MB and 256MB SD cards.
Yes, it's normal, I think the cards have lots of spare sectors to
allow remapping for write wear. I've seen it in smaller cards too.
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| Yura Pismerov 2005-02-04, 5:46 pm |
|
As the matter of fact this is an international standard (1MB==1000B).
IMHO this is very reasonable considering the size of the consumers market share.
And the megabytes that the computer and other technically savvy people got used to (2^10), are in fact called MiB.
I don't recall the exact name of that standard but I did see it at some point.,,
Alun Saunders wrote:
> Peter wrote:
>
>
>
> 488*1024*1024=511705088 ... not far off
>
> It's the same with hard disks. Most manufacturers define a MByte as
> having 1,000,000 bytes and most OS's define it (correctly) as
> 1024*1024=1048576 bytes. Plus you've got formatting overhead for
> whatever file system you are using.
>
> FWIW my el cheapo Lidl sourced 512MByte SD card gives a capacity of
> 513,015,808 bytes or 498MBytes formatted as FAT.
--
Yuri Pismerov, Sr. System Administrator,
TUCOWS.COM INC. (416) 535-0123 ext. 1352
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| David Schultz 2005-02-04, 8:45 pm |
| There is 512MB on the card. In order for it to be reasonably useful to a
computer it must be organized in some way. So the formatting process creates a
file system and this is what is consuming all of that space. My 64MB MMC card
has 60.9MB free after formatting. That is about 5% overhead in both cases.
If you don't need a file system then the full 512 MB is available.
Peter wrote:
> I have three of these, all brand new. All show 488MB as the size when
> formatting them and this is matched by the size of the files that can
> be transferred to them from a PC.
>
> Even allowing for 1k being 1024 etc this is a very big shortfall.
>
> Is this normal? I haven't seen it on 128MB and 256MB SD cards.
>
> They are used in PDAs to store GPS moving map data.
>
>
> Peter.
> --
> Return address is invalid to help stop junk mail.
> E-mail replies to peter1234@peter2000XY.co.uk but remove the X and the Y.
> Please do NOT copy usenet posts to email - it is NOT necessary.
--
David W. Schultz
http://home.earthlink.net/~david.schultz
Just because you wind up naked doesn't make you an emperor. - M.A. Padlipsky
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| In message <6277011f1js1r7bvvqog8s4qvgb4neh07k@4ax.com>, Peter
<peter@no-spam-please-6644.co.uk> wrote
>
>I have three of these, all brand new. All show 488MB as the size when
>formatting them and this is matched by the size of the files that can
>be transferred to them from a PC.
>
>Even allowing for 1k being 1024 etc this is a very big shortfall.
1k is actually 1000 when referring to hard disks, and presumably SD
cards.
A computer may report 1k byte as 1024 bytes. M$ Windows reports both
figures.
Converting from the true figure to the alternative (approximate) form of
reporting size gives
(512 x 1000 x 1000) / (1024x1024) = 488
--
Alan
mailto:news2me_a_2003@amacleod.clara.co.uk
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| In message <11078fa8641ne9a@news.supernews.com>, Alun Saunders
<notalun@notsaunders.net> wrote
>most OS's define it (correctly) as 1024*1024=1048576 bytes.
Er, no. The 1000x1000 figure is correct
The majority of data sheets for memory chips that I've seen give the
exact number of elements rather than the 'shorthand' and often
misleading Mbyte figure.
A manufacturer is more likely to quote a figure of 1048576 memory
locations rather than saying 1Mbytes or 1.04Mbytes. Often memory chips
don't come in sizes that conform to exact byte boundaries - they often
have locations usually used by designers for parity checking etc.
The marketing department will use the figure that appears to be larger
--
Alan
mailto:news2me_a_2003@amacleod.clara.co.uk
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| Alun Saunders 2005-02-05, 5:45 pm |
| Alan wrote:
> In message <11078fa8641ne9a@news.supernews.com>, Alun Saunders
> <notalun@notsaunders.net> wrote
>
>
> Er, no. The 1000x1000 figure is correct
It depends on your definition of "correct", I suppose.
Ever since I've been working in the computer field, which is getting for
27 years now, a kByte has been 1024 bytes and a MByte has been 1048576
bytes, at least for RAM, ROM and suchlike. I can't honestly say whether
hard disks way back then (which were in the order of 5 or 10 MBytes)
used that or the 10^6 version, and let's face it with capacities like
that the absolute difference between the two is pretty small, but I
still find it misleading to use one definition for memory and another
for storage purposes, and historically I find the 1 MByte=1048576 bytes
the more "correct" one. You can think what you like, however.
--
Alun Saunders
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| Yura Pismerov 2005-02-06, 2:45 am |
|
Found it:
http://physics.nist.gov/cuu/Units/binary.html
Yura Pismerov wrote:
>
> As the matter of fact this is an international standard (1MB==1000B).
> IMHO this is very reasonable considering the size of the consumers
> market share.
> And the megabytes that the computer and other technically savvy people
> got used to (2^10), are in fact called MiB.
> I don't recall the exact name of that standard but I did see it at some
> point.,,
>
>
> Alun Saunders wrote:
>
>
>
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| Malcolm Weir 2005-02-07, 5:45 pm |
| On Sat, 05 Feb 2005 19:45:37 +0000, Alun Saunders
<notalun@notsaunders.net> wrote:
>Alan wrote:
>
>It depends on your definition of "correct", I suppose.
How about the SI units?
>Ever since I've been working in the computer field, which is getting for
>27 years now, a kByte has been 1024 bytes and a MByte has been 1048576
>bytes, at least for RAM, ROM and suchlike.
True, and they've incorrectly been using SI prefixes all the time!
You do know that a Kg is not 1024g, and a Km is not 1024m, right?
> I can't honestly say whether
>hard disks way back then (which were in the order of 5 or 10 MBytes)
>used that or the 10^6 version, and let's face it with capacities like
>that the absolute difference between the two is pretty small, but I
>still find it misleading to use one definition for memory and another
>for storage purposes, and historically I find the 1 MByte=1048576 bytes
>the more "correct" one. You can think what you like, however.
How many bits per second can you send down a 1 megabit/sec line?
It has *never* been anything than 1,000,000. Because frequencies
(1MHz) have always been correct.
Still, in the early days, disk manufacturers sometimes quoted
capacities in units of 2000 sectors, each of 512 bytes, i.e. 1024000
byes (also called "megabytes").
The correct prefix for the binary power is "Mebi", written "Mi", as in
"Mebibytes" (MiB).
Malc.
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| Pieter Litchfield 2005-02-07, 8:45 pm |
| While there may a more correct abbreviation, I do believe that in terms of
hard drive and RAM byte capacities, the 1024 = 1K thesis is in fact,
correct. For years computer users have been either slightly and usually
inconsequently off, but if you ever puzzled over the numbers that a drive
manufacturer offers for capacity and then look at the report generated by a
directory listing, there has always been that strange and wonderful
disparity between the "real" K or Mb measurement and the binary K or Mb
measurement. Somehow the disks never quite measure up to their claims.
Transmission bandwidth is a different story. Bandwidth has often been
reported as "bits per second" and then again as "bytes per second" or even
"baud" (which I understand is the number of waveform edges per second).
Bytes of throughput may be deceptive since a transmitted byte can be various
number of bits depending on ASCII convention followed and checkbits
transmitted, etc. So in computerese it seems there is no *absolute* 1K or
1Mb. Goodness knows, there ain't no "correct", just conventions.
"Malcolm Weir" <malc@gelt.org> wrote in message
news:aptf01pmlnon4jeacgv7bh4dkdrb3t1obh@
4ax.com...
> On Sat, 05 Feb 2005 19:45:37 +0000, Alun Saunders
> <notalun@notsaunders.net> wrote:
>
>
> How about the SI units?
>
>
> True, and they've incorrectly been using SI prefixes all the time!
>
> You do know that a Kg is not 1024g, and a Km is not 1024m, right?
>
>
> How many bits per second can you send down a 1 megabit/sec line?
>
> It has *never* been anything than 1,000,000. Because frequencies
> (1MHz) have always been correct.
>
> Still, in the early days, disk manufacturers sometimes quoted
> capacities in units of 2000 sectors, each of 512 bytes, i.e. 1024000
> byes (also called "megabytes").
>
> The correct prefix for the binary power is "Mebi", written "Mi", as in
> "Mebibytes" (MiB).
>
> Malc.
| |
| John R. Copeland 2005-02-08, 7:51 am |
| Recalling some fundamentals ---
Here's why the Kilo-, Mega-, and Giga- terms were appealing.
2^10 ~ 1K
2^20 ~ 1M
2^30 ~ 1G
2^40 ~ 1T
etc.
It's a curious blend of base-2 numbers and base-10 groupings.
Early computer people liked that, and ran with it.
FWIW, that predated the time when a byte was universally 8 bits.
"Pieter Litchfield" <pvcl@*nospam*plitch.com> wrote in message =
news:ruVNd.34446$ZD1.8897@twister.nyroc.rr.com...
> While there may a more correct abbreviation, I do believe that in =
terms of=20
> hard drive and RAM byte capacities, the 1024 =3D 1K thesis is in fact, =
> correct. For years computer users have been either slightly and =
usually=20
> inconsequently off, but if you ever puzzled over the numbers that a =
drive=20
> manufacturer offers for capacity and then look at the report generated =
by a=20
> directory listing, there has always been that strange and wonderful=20
> disparity between the "real" K or Mb measurement and the binary K or =
Mb=20
> measurement. Somehow the disks never quite measure up to their =
claims.
> Transmission bandwidth is a different story. Bandwidth has often been =
> reported as "bits per second" and then again as "bytes per second" or =
even=20
> "baud" (which I understand is the number of waveform edges per =
second).=20
> Bytes of throughput may be deceptive since a transmitted byte can be =
various=20
> number of bits depending on ASCII convention followed and checkbits=20
> transmitted, etc. So in computerese it seems there is no *absolute* =
1K or=20
> 1Mb. Goodness knows, there ain't no "correct", just conventions.
>
| |
| Malcolm Weir 2005-02-08, 7:51 am |
| On Tue, 08 Feb 2005 02:29:43 GMT, "Pieter Litchfield"
<pvcl@*nospam*plitch.com> wrote:
>While there may a more correct abbreviation, I do believe that in terms of
>hard drive and RAM byte capacities, the 1024 = 1K thesis is in fact,
>correct.
The SI folks disagree. You lose.
> For years computer users have been either slightly and usually
>inconsequently off, but if you ever puzzled over the numbers that a drive
>manufacturer offers for capacity and then look at the report generated by a
>directory listing, there has always been that strange and wonderful
>disparity between the "real" K or Mb measurement and the binary K or Mb
>measurement. Somehow the disks never quite measure up to their claims.
Nope. They live up to their claims, you just didn't read what the
claim really WAS. You just presumed that they were making the same
mistake as you...
>Transmission bandwidth is a different story.
No, it isn't. Same deal. Same prefix.
> Bandwidth has often been
>reported as "bits per second" and then again as "bytes per second" or even
>"baud" (which I understand is the number of waveform edges per second).
Not really. Baud is the number of information units per second. An
information unit may be one or more than one bit.
>Bytes of throughput may be deceptive since a transmitted byte can be various
>number of bits depending on ASCII convention followed and checkbits
>transmitted, etc.
Sure. But a 1Mbit/sec line is not deceptive: it transmits 1,000,000
bits per second.
By the way, you know your PCI bus at 32 bits wide and 33MHz transmits
132,000,000 bits per second, right? As in 132MB/sec.
> So in computerese it seems there is no *absolute* 1K or
>1Mb. Goodness knows, there ain't no "correct", just conventions.
False. There *is* a correct usage, and common (incorrect usage).
I mean, where did we *get* the prefixes K, M, G, and T, etc...?
Look, we've been misusing those SI prefixes for years. We know what
we mean. But let's not pretend that the misuse is "correct".
Malc.
| |
| Anton Rang 2005-02-08, 5:45 pm |
| Malcolm Weir <malc@gelt.org> writes:
> By the way, you know your PCI bus at 32 bits wide and 33MHz transmits
> 132,000,000 bits per second, right? As in 132MB/sec.
(you meant bytes per second, but the number's right.)
> Look, we've been misusing those SI prefixes for years. We know what
> we mean. But let's not pretend that the misuse is "correct".
Yup.
Anton
| |
| Randolph J. Herber 2005-02-08, 5:45 pm |
| In article <ruVNd.34446$ZD1.8897@twister.nyroc.rr.com>,
Pieter Litchfield <pvcl@*nospam*plitch.com> wrote:
>While there may a more correct abbreviation,
They are defined. It is the computer people that are
misusing the metric prefixes and positive powers fof 1024
prefixes have been defined but as of yet are not commonly used.
http://physics.nist.gov/cgi-bin/cuu...its/binary.html
http://physics.nist.gov/cgi-bin/cuu...s/prefixes.html
(( For the EU residents, this is an international standard
which is applicable to the EU as well as the rest of
the world.
))
The ``marketeers'' prefer to use the SI/metric prefixes
rather than the binary prefixes as they give bigger numbes.
The computer ``nerds'' prefer the binary sized meanings
as they more correctly their pattern of usage.
Now just get the computer ``nerds'' to switch from
1.073741824 to 1GiB (512MB = 488.28125MiB).
>1Mb. Goodness knows, there ain't no "correct", just conventions.
There is a ``correct.'' But, generally, people are
not using it as they are continuing their old practices.[vbcol=seagreen]
Ipse dixit.
(( In the original meaning of the Latin expression:
he/she/it said it (him/her/it)self.
))
Randolph J. Herber, herber@fnal.gov, +1 630 840 2966, CD/CDFTF PK-149F,
Mail Stop 318, Fermilab, Kirk & Pine Rds., PO Box 500, Batavia, IL 60510-0500,
USA. (Speaking for myself and not for US, US DOE, FNAL nor URA.) (Product,
trade, or service marks herein belong to their respective owners.)
| |
| Morten Reistad 2005-02-08, 8:45 pm |
| In article <aptf01pmlnon4jeacgv7bh4dkdrb3t1obh@4ax.com>,
Malcolm Weir <malc@gelt.org> wrote:
>On Sat, 05 Feb 2005 19:45:37 +0000, Alun Saunders
><notalun@notsaunders.net> wrote:
>
>
>How about the SI units?
>
>
>True, and they've incorrectly been using SI prefixes all the time!
>
>You do know that a Kg is not 1024g, and a Km is not 1024m, right?
>
>
>How many bits per second can you send down a 1 megabit/sec line?
>
>It has *never* been anything than 1,000,000. Because frequencies
>(1MHz) have always been correct.
Bzzt.
If you are thinking about the same 1-megabit lines as the G.703/G.704
lines standardize (and common throughout Europe and with some availability
in the rest of the world) i have to disappoint you.
G.703 specifies the bit rate as 2048000 +/- 2 bits per second, and
G.704 divides this into 32 timeslots of 64000 bits per second. All
designed to transmit 8000 samples of 8 bits per second.
A 1-megabit line has 16 timeslots for 1024000 bits per second.
>Still, in the early days, disk manufacturers sometimes quoted
>capacities in units of 2000 sectors, each of 512 bytes, i.e. 1024000
>byes (also called "megabytes").
>
>The correct prefix for the binary power is "Mebi", written "Mi", as in
>"Mebibytes" (MiB).
Yeah, right.
-- mrr
| |
| Morten Reistad 2005-02-08, 8:45 pm |
| In article <rjBOCrCddMBCFwdo@amacleod.clara.co.uk>,
Alan <news2me_a_2003@amacleod.clara.co.uk> wrote:
>In message <6277011f1js1r7bvvqog8s4qvgb4neh07k@4ax.com>, Peter
><peter@no-spam-please-6644.co.uk> wrote
>
>1k is actually 1000 when referring to hard disks, and presumably SD
>cards.
>
>A computer may report 1k byte as 1024 bytes. M$ Windows reports both
>figures.
>
>Converting from the true figure to the alternative (approximate) form of
>reporting size gives
>
>(512 x 1000 x 1000) / (1024x1024) = 488
So when the computer salesman (it is usually a male) sold you 512 meg
of storage for $0.1k, and you ended up with 488000000 bytes for $102.40.
(sorry about old joke, just appropriate for the setting).
-- mrr
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| djwhizzard@hotmail.com 2005-02-25, 2:45 am |
| Standards are only useful when adopted.
Although very intelligent people define the standards to which we
should adhere, the standards are ultimately set by the people who would
use them.
I understand the need for differentiating between 2^20 and 10^6, but
you'll be hard pressed to find more than 1 in 10 computer "nerds" who
are willing to refer to "Kilobits" as "Kibibits" or "Kaybee's" as
"Kibee's." *cringe*
Sometimes technically-oriented people overlook the real-world aspect of
what they do.
I think the lack of wide-spread adoption of this standard after seven
years is saying something. I think that until the manufacturers, namely
Memory Manufacturers, adopt this "new" standard, it's going to remain
jargon that only the truly savvy understand. Until then, the rest of us
are going to have to refer to the fine print if we want real numbers.
| |
| Andrew 2005-02-25, 2:45 am |
| On 24 Feb 2005 19:24:15 -0800, djwhizzard@hotmail.com wrote:
>I understand the need for differentiating between 2^20 and 10^6, but
>you'll be hard pressed to find more than 1 in 10 computer "nerds" who
>are willing to refer to "Kilobits" as "Kibibits" or "Kaybee's" as
>"Kibee's." *cringe*
Personally, as a "computer nerd", if I heard someone saying "Kaybee" I
would assume they meant Kilobytes.
--
Andrew, contact via interpleb.blogspot.com
Help make Usenet a better place: English is read downwards,
please don't top post. Trim replies to quote only relevant text.
Check groups.google.com before asking an obvious question.
| |
| Yura Pismerov 2005-02-25, 5:45 pm |
|
If you have a Linux box available, try to login and run "/sbin/ifconfig eth0|grep bytes".
Surprise, surprise !
And Linux is a system that is run (mostly) by nerds...
djwhizzard@hotmail.com wrote:
> Standards are only useful when adopted.
>
> Although very intelligent people define the standards to which we
> should adhere, the standards are ultimately set by the people who would
> use them.
>
> I understand the need for differentiating between 2^20 and 10^6, but
> you'll be hard pressed to find more than 1 in 10 computer "nerds" who
> are willing to refer to "Kilobits" as "Kibibits" or "Kaybee's" as
> "Kibee's." *cringe*
>
> Sometimes technically-oriented people overlook the real-world aspect of
> what they do.
>
> I think the lack of wide-spread adoption of this standard after seven
> years is saying something. I think that until the manufacturers, namely
> Memory Manufacturers, adopt this "new" standard, it's going to remain
> jargon that only the truly savvy understand. Until then, the rest of us
> are going to have to refer to the fine print if we want real numbers.
>
--
Yuri Pismerov, Sr. System Administrator,
TUCOWS.COM INC. (416) 535-0123 ext. 1352
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