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4GB SDHC Cards . . .

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by who am i really 2 views

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anyone have a decent explanation for this:

every SD Card & various Flash Drives I have use the entire space on the chip(s) in them
for the "partition"

however, every one of my SDHC cards don't use the entire space,
disk management reports that they all have a 4MB unallocated space at the beginning of the "drive",
is there any particular reason for this ripping me off of with unallocated space?

Is it safe to blast the partition and replace it with one that spans the entirety of the SDHC card or will that kill it? (x_x)

11 replies

by michael jay

cool name, must be where you keep all the secret squirrel stuff.

by seanferd

even if it is a valid partition. It just isn't a Windows partition. Windows can "recognize" (unknown!) some partitions (but not access them), but it cannot recognize some others.

Just a possibility.

by jaymzkerten

4MB is very minimal. Sure it is space that is going unused, but when you are comparing it to the size of the card itself (4GB), you are really going through the trouble to gain 0.1% additional space.

by who am i really

I've been around since the days when a 20MB HDD was a big deal and any amount of space lost is space lost regardless of the percentage

it's bad enough that some time back when the 2GB HDD was king that the various HDD Mfg. got greedy and flipped the number scheme
from binary to decimal
ie.
- a 360KB floppy formats to 365KB usable space
- a 720KB floppy formats to 730KB
- a 1.2MB floppy formats to 1.21MB
- a 1.44MB floppy formats to 1.457MB
- an 80MB HDD formats to 84MB
- a 234MB HDD formats to 245MB
- a 250MB HDD formats to 262MB
- a 400MB HDD formats to 420MB
- etc.

but, a 4GB HDD is actually only a 3.69GB HDD
and a 320GB HDD is actually only a 298GB HDD
etc.

So I tend to get a bit choked when winders won't use the entire space of an HDD whether it be 2GB - 2TB in size

I usually set them up externally first so that I can test first and so that winders won't leave the 7MB for dynamic disk conversion off at the end of the disk because an external can't be a dynamic disk only basic

by who am i really

that's where all files appear and disappear from "Area 51"

and because my backup program (BESR 6.52)
chokes on NTFS junction points so I can't put them on the C:\ (the only thing backed up by BESR)

I mount all my drives in one location
(the small NTFS drive Area 51)
and share out that location
by using "mount in NTFS folder" to mount entire drives, I have the closest possible equivalent to the old style DOS / win9x sharing.

by michael jay

partitions show as other than unknown, unallocated usually seems to mean there really is nothing there.

I would just wack the whole thing and format and see what happens.

Also all the SDHC memory I have used only have one partition, no unallocated space, and I use a bunch with my cameras.

by who am i really

and the card reader

as to whether it shows the unallocated space or not

I have on my main works station several 1TB drives and a 1.5TB drive
and a USB Card reader

the Same SDHC card doesn't show the unallocated space on this system

as it does when attached to the system with the 120GB HDD
through the integrated SD card reader on the notebook which is directly connected to the PCMCIA bus

the main workstation won't show the 1MB unallocated at the end of some of my e-SATA 500GB disks but when attached to the e-SATA controller of a system with smaller internal drives all of a sudden this 1MB unallocated appears

it has something to do with the calculations used to size the representation of the drive in disk management

by michael jay

because I really do not know, that it has to do with the addressing scheme of the system involved.

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