13.5 GB free.... I thought this was the TWENTY gig model?

most companies that sel hard drives tend to round up a fair bit, my 250gb hard drive is 217gballmont

Companies don't round up ... that would be false advertising. They are telling the truth, it's just not what you expect.

First let's look at the units of space. The smallest unit of space is a byte, then we go to kilobytes, then megabytes, then gigabytes. People generally say that1,000 bytes equals a kilobyte, 1,000 kilobytes equals a megabyte, 1,000 megabytes equals a gigabyte, but this is actually false. Computers use binary to count, due to the nature of binary, the progression of countingis 1, 2, 4, 8, 16, etc ... now, if you follow this progression you will find that the closest number to 1,000 is actually 1,024. This total disregard for the extra 24 bytes carries over at every stage of the process, resulting in what seems to be a smaller drive than what you thought you had. How many kilobytes in a megabytes? 1,000?? WRONG. 1,024.

Now due to this we get the following issue.
A shop will say to you "Here is a 1GB Drive" and technically what they are saying to you is "Here is a drive with 1,000,000,000 bytes of space on it".But by taking the 1,000,000,000 bytes and dividing by 1,024 to turn it into kilobytes, then by 1,024 again to make megabytes, and 1,024 again to make gigabytes, you will find that the REAL capacity is about 0.931GB. Of course the larger the space you are talking about, the bigger the difference between what you are TOLD you are getting, and what you really get.

This however is not the reason for the 20GB Xbox drive having only 13GB space. That's due to the space reserved for caching and other stuff.

[QUOTE="allmont"]most companies that sel hard drives tend to round up a fair bit, my 250gb hard drive is 217gbWillcow

Companies don't round up ... that would be false advertising. They are telling the truth, it's just not what you expect.

First let's look at the units of space. The smallest unit of space is a byte, then we go to kilobytes, then megabytes, then gigabytes. People generally say that1,000 bytes equals a kilobyte, 1,000 kilobytes equals a megabyte, 1,000 megabytes equals a gigabyte, but this is actually false. Computers use binary to count, due to the nature of binary, the progression of countingis 1, 2, 4, 8, 16, etc ... now, if you follow this progression you will find that the closest number to 1,000 is actually 1,024. This total disregard for the extra 24 bytes carries over at every stage of the process, resulting in what seems to be a smaller drive than what you thought you had. How many kilobytes in a megabytes? 1,000?? WRONG. 1,024.

Now due to this we get the following issue.
A shop will say to you "Here is a 1GB Drive" and technically what they are saying to you is "Here is a drive with 1,000,000,000 bytes of space on it".But by taking the 1,000,000,000 bytes and dividing by 1,024 to turn it into kilobytes, then by 1,024 again to make megabytes, and 1,024 again to make gigabytes, you will find that the REAL capacity is about 0.931GB. Of course the larger the space you are talking about, the bigger the difference between what you are TOLD you are getting, and what you really get.

This however is not the reason for the 20GB Xbox drive having only 13GB space. That's due to the space reserved for caching and other stuff.

^ That guy just /thread

[QUOTE="allmont"]most companies that sel hard drives tend to round up a fair bit, my 250gb hard drive is 217gbWillcow

Companies don't round up ... that would be false advertising. They are telling the truth, it's just not what you expect.

First let's look at the units of space. The smallest unit of space is a byte, then we go to kilobytes, then megabytes, then gigabytes. People generally say that1,000 bytes equals a kilobyte, 1,000 kilobytes equals a megabyte, 1,000 megabytes equals a gigabyte, but this is actually false. Computers use binary to count, due to the nature of binary, the progression of countingis 1, 2, 4, 8, 16, etc ... now, if you follow this progression you will find that the closest number to 1,000 is actually 1,024. This total disregard for the extra 24 bytes carries over at every stage of the process, resulting in what seems to be a smaller drive than what you thought you had. How many kilobytes in a megabytes? 1,000?? WRONG. 1,024.

Now due to this we get the following issue.
A shop will say to you "Here is a 1GB Drive" and technically what they are saying to you is "Here is a drive with 1,000,000,000 bytes of space on it".But by taking the 1,000,000,000 bytes and dividing by 1,024 to turn it into kilobytes, then by 1,024 again to make megabytes, and 1,024 again to make gigabytes, you will find that the REAL capacity is about 0.931GB. Of course the larger the space you are talking about, the bigger the difference between what you are TOLD you are getting, and what you really get.

This however is not the reason for the 20GB Xbox drive having only 13GB space. That's due to the space reserved for caching and other stuff.