Jump to content

HD 250 GB is recognized as 128 GB.

MorphewS
 Share
13 posts in this topic

Recommended Posts

DiaboliK
DiaboliK
Posted
Posted
I've got a Seagate Barracuda 7200.10 320GB 7200 RPM SATA that registers as 298GB? could be a similar problem. I did a clean install of osx, single boot from a JaS 10.4.5 dvd and updated to 10.4.8. curious?

 

have you ever read the small print on the hd box?

 

its theoretically 320gb but in real usable bytes its more like 300gb.

 

for example: the note from the ipod shuffle : 1GB = 1 billion bytes; actual formatted capacity less.

macbrush
macbrush
Posted
Posted

It depends on your VM created VM Volume size, not your physical HD size. You can use vmware-vdiskmanager to resize your VM partitions.

 

I Have Seagate 250 GB 7200.10 SATA II, ABIT AB9 Pro, C2D E4300, 1 GB Kingston 533.

Mine hd is configured to mode AHCI, but in Vmware and OSX my hd is recognized as 128 GB, MACs only support 128 GB?

 

hdas128gbgo1.th.jpg

 

Thx for help :D

kernalzero
kernalzero
Posted
Posted

Diabolik, I've heard that answer before now that you mention it. Wish I had the box but it was an OEM drive from newegg. oh well it's plenty, I'd rather have osx recognize it as 300GB on my hackintosh that run windows and have it recognized as 320....thanks for the answer

  • 4 weeks later...
eire3678
eire3678
Posted
Posted
Diabolik, I've heard that answer before now that you mention it. Wish I had the box but it was an OEM drive from newegg. oh well it's plenty, I'd rather have osx recognize it as 300GB on my hackintosh that run windows and have it recognized as 320....thanks for the answer

 

It doesn't matter what operating system you use. A 320GB hard drive will never actually format to 320GB. The formatted size of any drive will always be approximately 93.125% of the sold-as size. Not to mention the sold-as size rounds off bite measurements, as was mentioned.

 

As for the 128GB problem, that has to do with antiquated drivers for the ATA emulation. Up until the second revision of the Quicksilver (and a few lucky Quicksilver G4s before that) Macs shipped with ATA/33 or ATA/66 interfaces that were limited to drive sizes of 128GB. Didn't matter how large the drive was, anything past that 128GB mark wouldn't be seen. But as to which file to remove I wouldn't have a clue, just a little history lesson :)

  • 3 weeks later...
Zulu.Walker
Zulu.Walker
Posted
Posted
I had that issue with my Western Digital WD2500 (250gb) on a showing up as 128GB, it was the apple generic ata driver doing it. i removed it in favour of appleviatata. It immediately showed up as 250gb.

 

Worked for me. The AppleGenericPCATA.kext can be found in /S/L/E/IOATAFamily.kext/Contents/PlugIns. I just sudo mv'd it to a different location, repaired permissions, and OS X now detects my drive's correct size.

sarahbau
sarahbau
Posted
Posted
It doesn't matter what operating system you use. A 320GB hard drive will never actually format to 320GB. The formatted size of any drive will always be approximately 93.125% of the sold-as size. Not to mention the sold-as size rounds off bite measurements, as was mentioned.

 

To understand why this is true, you just have to understand how computers count. We think of 1 kilobyte as 1000 bytes, 1 megabyte as 1000 kilobytes, or 1,000,000 bytes, etc. A computer thinks of 1 kilobyte a 1024 bytes (it's a binary system, so 2^10), and 1 megabyte as 1,024 kilobytes, or 1,048,576 bytes. By the time you get to gigabytes, there is a big difference. To a computer, a gigabyte is 1,073,741,824 bytes. Take that 320GB drive (which is 320,000,000,000 bytes), and divide by the computer's definition of a GB, and you get 298GB. It's not really an issue of formatting, though for some reason it's almost always referred to as "formatted capacity." You're still getting 320 billion bytes.

 

This has led to a new system when it comes to computers. If you've seen something say 4.7GiB or 100MiB, it's in gibibytes and mebibytes, meaning they're using the binary system computers use to determine size. Most software and people don't use this system though.

Falcon351
Falcon351
Posted
Posted
To understand why this is true, you just have to understand how computers count. We think of 1 kilobyte as 1000 bytes, 1 megabyte as 1000 kilobytes, or 1,000,000 bytes, etc. A computer thinks of 1 kilobyte a 1024 bytes (it's a binary system, so 2^10), and 1 megabyte as 1,024 kilobytes, or 1,048,576 bytes. By the time you get to gigabytes, there is a big difference. To a computer, a gigabyte is 1,073,741,824 bytes. Take that 320GB drive (which is 320,000,000,000 bytes), and divide by the computer's definition of a GB, and you get 298GB. It's not really an issue of formatting, though for some reason it's almost always referred to as "formatted capacity." You're still getting 320 billion bytes.

 

This has led to a new system when it comes to computers. If you've seen something say 4.7GiB or 100MiB, it's in gibibytes and mebibytes, meaning they're using the binary system computers use to determine size. Most software and people don't use this system though.

 

 

"Formatted capacity" refers to capacity after the disk has been formatted into sectors. Some of the bits are used for sector gaps, to allow the controller to identify the start/end of each sector on a track, and these can't be used for storing user data (the "user" in this case being the OS/file system). An unformatted disk can't be used, so unformatted capacity is pretty much useless information.

 

The above paragraph refers to low-level formatting, then there's high-level (logical) formatting on top of that, such as partition tables and file system structures.

 Share
Go to topic listing
×
×
  • Create New...