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Rod Speed

Dark1 wrote:
"krw" wrote in message
t...
In article bPVDi.1802$s06.267@trnddc04,
says...

"krw" wrote in message
t...
In article ,
says...
Terry wrote in
oups.com:

They are just padding the numbers. It is a good thing she found
this
information before she packed it up and took it back for nothing.

While I agree that the advertising is misleading it is common
practice
to report installed memory as opposed to 'usable' memory.

Likewise for hard disks, where the size is often reported as
unformatted, which is completely useless, of course. Then
depending on what file system it is formatted in (NTFS for
example) you get a big chunk devoted
to the file system and not available for your stuff.

No, there is no difference between formatted and unformatted disk
size (unformatted disk drives don't exist in the wild). The issue
is that disks are sold by the decimal megabyte (10^6 bytes) rather
than binary "megabytes" (2^16 bytes) as memory is.

No you're wrong again. Disks are indeed just blank platters until
formatted
which is why when you buy a hard drive it does not say "for PCs
only."

Wrong. Hard disk are formatted at the factory. They're non-
functional without formatting. I haven't seen a disk marked "for PCs
only" since the year of the flood.

You
can take any SCSI drive for example and use it in a PC, MAC, Unix,
VMS, IBM,
Cray, Unisys or whatever - all sharing the same interface, all
incompatible
file systems and drive formats and logical architecture. Depending
on the
OS and the file system, there is loss due to allocation table
overhead and
also due to the fact that under NTFS and most others such as FAT and
FAT32
there are the same number of sectors per track.

File system formatting. The OS can install its own filesystem.
It *cannot* format a modern drive. Without formatting the hardware
has no clue how to access the drive - no index marks, no track marks,
no clocks, nothing.

Very few OSs actually use
variable sector mapping. Oddly enough the old Commodore 64 was
one. You fit the same number of sectors on a center track as an
edge track therefore
you lose more space at the outside of the disk. Picture a pie cut
in wedges.

No, modern disk have more sectors on the outside tracks (see: "zoned
recording"). The sectors are the same sized though. Variable
sectors aren't worth the overhead, given the size of disks these
days.

Originally, disk drives were actually drums for this very reason -
far easier to work with and the only way they could get any
respectable capacity - and where we get terms like cylinder from. The next factor is the cluster size itself.
Smaller clusters
require more management but are
less wasteful. Larger clusters waste more space but are better for
ECC and
performance.

Meaningless to the discussion...

For the sake of this discussion, NTFS has about a 10% file
overhead. A 160
GB drive will format out to about 145-148 GB. The rest is just
wasted space
and table space. This is a general rule of thumb as NTFS chooses
the cluster size based on the partition size. You can however,
change that. You can run NTFS with different cluster sizes but it
introduces other issues. As disk formats go, NTFS is one of the
more wasteful. But it really does not matter since the cost per
gig is so incredibly low.

Also meaningless...

Class dismissed.

Demand a tuition refund.

bah.. unfamiliar with low level factory formatting I see.. (which really is irrelevant to the disk size issue, they
simply use a different definition of a megabyte, manufacturers define it at 1,000,000 bytes,

So does the SI.

while the os works only in numbers divisible by 8, starting at the kilobyte)

Pig ignorant lie. Even the MS OSs often report the decimal format.

maybe this will help with the formatting
http://en.wikipedia.org/wiki/Low_lev..._of_formatting

It clearly didnt help you.