| Rev | Author | # | Line |
|---|---|---|---|
| 1 | DanielLawson | 1 | An Acronym for __L__ogical __B__lock __A__ddressing |
| 2 | |||
| 5 | AristotlePagaltzis | 3 | [LBA] is a addressing scheme for HardDisk sectors that uses a single number starting at 0. It supersedes the classic [CHS] addressing. |
| 1 | DanielLawson | 4 | |
| 5 | AristotlePagaltzis | 5 | [LBA] addresses can be 28 bit or 48 bit wide. |
| 1 | DanielLawson | 6 | |
| 5 | AristotlePagaltzis | 7 | With the common 512 byte sector size, 28 bits are somewhat limiting:'''' |
| 1 | DanielLawson | 8 | |
| 5 | AristotlePagaltzis | 9 | 512 byte sectors = 2<sup>9</sup> Bytes |
| 1 | DanielLawson | 10 | |
| 5 | AristotlePagaltzis | 11 | 2<sup>28</sup> * 2<sup>9</sup> Bytes = 2<sup>37</sup> Bytes = 137,438,953,472 Bytes |
| 1 | DanielLawson | 12 | |
| 5 | AristotlePagaltzis | 13 | That is 128[GiB]:'''' |
| 1 | DanielLawson | 14 | |
| 5 | AristotlePagaltzis | 15 | 1 [GiB] = 2<sup>30</sup> Bytes |
| 1 | DanielLawson | 16 | |
| 5 | AristotlePagaltzis | 17 | 2<sup>37</sup> Bytes / 2<sup>30</sup> = 2<sup>7</sup> [GiB] = 128 [GiB] |
| 1 | DanielLawson | 18 | |
| 5 | AristotlePagaltzis | 19 | Disk manufacturers actually use [GB], btw:'''' |
| 1 | DanielLawson | 20 | |
| 5 | AristotlePagaltzis | 21 | 1 [GB] = 10<sup>9</sup> Bytes |
| 22 | |||
| 23 | 2<sup>37</sup> Bytes / 10<sup>9</sup> = 137.43 [GB] | ||
| 24 | |||
| 25 | This is the reason for older OperatingSystem~s or controllers without 48 bit [LBA] support failing to detect a large contemporary disk correctly. | ||
| 26 | |||
| 27 | 48 bit [LBA] offers much larger disks:'''' | ||
| 28 | |||
| 29 | 2<sup>48</sup> * 2<sup>9</sup> Bytes / 2<sup>30</sup> = 2<sup>27</sup> [GiB] = 134,217,728 [GiB] = 128 EB | ||
| 30 | |||
| 31 | ---- | ||
| 1 | DanielLawson | 32 | Part of CategoryHardware |
