Posted 01 April 2005 - 03:44 PM
From my understanding the size displayed on the box is a selling point. Most hard driver manufactures define one gigabyte as 1 billion bytes, where as every computer geek in the world knows that 1 gigabyte is 1024 megabytes. If one mega byte is 1024 kilobytes, and one kilobyte is 1024 bytes the math would work out as follows
1 KB = 1024 Bytes
1 MB = 1024 KBytes
1GB = 1024 MBytes
So in 1 GB there are actually 1,073,741,824 Bytes
If the manufactures say 1 GB = 1,000,000,000 Bytes you can see that there is a difference (or loss) of 73,741,824 Bytes or 7,2013.5 KBytes or 70.33 MBytes.
So for every GByte the manufacture SAYS you get you need to multiply that number by
So for a 120GByte Hard drive
120 x 70.33 = 8439.6 MBytes or 8.24 GBytes
So on a 120 GByte Hard drive you would actually get
120 - 8.24 = 111.76GBytes
Lets to the same for you 512 MByte Card
Lets assume the manufacture defines 1 MByte as 1 million (1,000,000) Bytes
And we all know 1 MByte is 1,048,576 Bytes
1,048,576 - 1,000,000 = 48,576 Bytes or 47.44 KBytes
Now multiply the size of your card by your loss number
512 x 47.44 = 24,289 KBytes or 23.71 MBytes
So on a 512 MB card you should get
512 - 23.71 = 488.29 MBytes
You say it has 463 MBytes free so that is a difference of
488 - 463 = 25MBytes
Also you have to take in to account the FileSystem the card / disk is formatted in, and any "system" files that my be hidden from view that the PSP needs.
All in all i think you got about what you payed for.
If anybody disagrees with anything above, please let me know, as I would gladly say I am wrong if you can prove it.