Thread: Exploring WD's encouraged Format HD engineering.

Western Digital lately began to ship a novel series of Caviar hard repels that admitted the company's encouraged Format engineering. The novel Caviar Green examples are almost very to their standard brethren, but extend repeat the cache (sixty-four MB rather of thirty-two MB at 1-2TB) and accept a dissimilar example number. A WD10EARS is an encouraged Format repel; a WD10-EADS is a 'normal' repel. WD isn't selling encouraged Format much at the moment, but it's significant to realize what the engineering is and how it exploits, especially if you're even campaigning Windows XP.


Hard repel sizes are generally afforded in terms of total memory capability, where one byte = ten bits. This is sometimes promote collapsed down by the number of records and the size of each. The 1st one TB repels, for example, utilized 5 200GB platters; current-generation one TB repels utilize 2 500GB records. These values, still, just mention to the approachable memory capacity, not the entire size of the record itself. This unseeable (to the end-user) additional capability is utilized to storage positional data and for fault correction code.




Encouraged Format alters a hard repels sector size from 512 bytes (the received for the past 3 decades) to 4K. This appropriates the ECC information we concerned to over to be put in more expeditiously.Each 1 of those ECC blocks is forty bits wide; a 4K block of information controls 320 bytes of ECC. Utilizing encouraged Format's novel 4096 sector size cuts the amount of ECC and Sync/DAM space importantly.


Granting to WD, it involves only 100 bytes of ECC information per 4096 byte sector below the novel scheme, a savings of 220 bytes. We require to clear up approximately mix-up considering the near-term gains of encouraged Format. In Western Digital's whitepaper on the subject (PDF), the company nations that it can "gain roughly 7-11% in disk space" by utilizing progressed Format.