# OMG 3 TB Hard Drive Exists!



## lockfile (Feb 13, 2011)

I am shopping around for a new external HD. My old 80G is getting a little small for me. So I'm looking for a 500 and up, or the largest I can get for under $100. So I'm browsing, and then this 3 terabyte monster HD came out at me: http://www.newegg.com/Product/Product.aspx?Item=N82E16822145466

I never knew that HDs are that big nowadays. Just 6 months ago 1TB was the biggest you could find, but now they got 3TB. That's crazy!


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## xibo (Feb 13, 2011)

2TB disks were around for at least a year. 3TB wasn't released only yesterday either, yet it's troublesome, because block sizes are 512 bytes, and partitions start and end on a multiples of n blocks, where n is an unsigned 32 bit integer in LBA, therefore 2TiB is the maximal size old systems can handle. For example, Windows XP can't handle all of that disk (just the first 2TiB).


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## jem (Feb 14, 2011)

LBA has used 48 bits since the ATA-6 standard was released in 2003, making 128 petabytes the largest addressable capacity using 512 byte sectors.  When disk manufacturers start exposing the new 4 kilobyte sector sizes to the OS, 1 exabyte of capacity will be addressable.

The old MBR partitioning scheme can't handle LBA's with more than 32 bits though, limiting partition size to 2TB.

Time to switch to GPT partitioning, which is good up to 9.4 zetabytes.


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