The tablet has a whole internal storage value of 32GB, however only 25.31GB's are available to the user.This is because of a mix of two factors; The actual storage value is rounded up to the nearest multiple of two, the usual real storage value of a flash storage disk is about 93 % of the advertisement. This means that the tablet real only has the capability of storing 32*.93 = 29.76 gigabytes. The other contributing factor is the system data of the operating system,which may conspire of around 4.45GB's. Leaving the available storage of 25.31GB's or 2531 megabytes because 1000 megabytes go into one gigabyte, or this can be represented as 1073741824*25.31= 2717640000 bytes this contains2717640000*8 bits per byte = 21741124450 bits.
For the sake of simplicity, when discussing the use of storage, I will only use storage of applications using the average storage the require on the tablet; The tablet is using 213MB's of storage for all it's applications and it has 44 applications on it, so on average each app uses 213/44 4.84MB's of storage. Using this I can calculate a estimation of how many apps the tablet can store; 2531/4.84=522 applications in total. But in saying this I realize that this number can vary by a lot; as tablet applications can consist from 4KB(0.000976563*4 = 0.00390625MB's) up to 20MB's. Note the number of applications I have now is smaller than usual, as I'm rebuilding my app base from a system wide with an update. But at this point I'm using 44/522= 8.43% of my application storage possibilities.
The applications are stored in a flash memory disk using the binary representation system; physically this stores the bits as the logic o or 1 as a high or a low witch is 10 volts for 1 and 0 for 0 ( its also possible the tablets internal circuitry is using logic level converter or another level entirely for storage). The flash memory stores the bits with two transistors (a transistor is a semiconductor that only lets current flow if there is a secondary current applied) separated by an oxide layer, this oxide layer traps electrons to maintain a logic level without external flow(power). The state of each transistor set (each bit) is changed by the state of the gates of the transistor by varying the number of trapped electrons, the logic values are distinguished by a electron-counter if there are less than half of the set amount its a 0, if there's more its 1.
Number storage example
The tablet displays a available storage value for the SD card that may be inserted, with the possible value size of 0-6400(MB). This is under the assumption my device has the capability of displaying the available storage even if there is no storage left, also that the SDHC storage technology is limited to 64(specifically) for my device. This number is displayed when navigating through the system settings. It is likely that this number is stored in the binary format within my device because of its vast range of possible values(6401); this would need 13 bits to store the identification of the four digits, this would use up to 2bytes of storage in the devices random access memory; because that is the max amount of bytes that the number would ever need. It is likely that my device only temporarily stores the value, because it would have to be recalculated every time its viewed. An example of the binary representation could be 1100100000000 for 6400. Alternative storage; it could be stored using Assci or Unicode instead of and integer; but in saying this within the code its probable that its stored as an integer and a string; as it will need to calculate the value in an integer data type but also converted it to display it, but more on this later.
information source on actual available storage on flash memory;
http://forums.ilounge.com/ipod-touch/222361-how-many-actual-gigs-there-32gb.html
No comments:
Post a Comment