New Egg now carries the WD Caviar Green 64mb cache drives with 4KB physical sectors to allow more of the space to actually be useable (less overhead). 

 

I've heard of issues with running these on Windows 5.x system (XP, WHS, etc.)  According to the Anandtech article Linux will have no issues with these drives.

 

Anandtech article on the technology: http://www.anandtech.com/storage/showdoc.aspx?i=3691

 

1Tb - http://www.newegg.com/Product/Product.aspx?Item=N82E16822136490&cm_re=wd_caviar-_-22-136-490-_-Product

 

1.5tb - http://www.newegg.com/Product/Product.aspx?Item=N82E16822136513&cm_re=wd_caviar-_-22-136-513-_-Product

New Egg now carries the WD Caviar Green 64mb cache drives with 4KB physical sectors to allow more of the space to actually be useable (less overhead). 

 

I've heard of issues with running these on Windows 5.x system (XP, WHS, etc.)  According to the Anandtech article Linux will have no issues with these drives.

 

Anandtech article on the technology: http://www.anandtech.com/storage/showdoc.aspx?i=3691

 

1Tb - http://www.newegg.com/Product/Product.aspx?Item=N82E16822136490&cm_re=wd_caviar-_-22-136-490-_-Product

 

1.5tb - http://www.newegg.com/Product/Product.aspx?Item=N82E16822136513&cm_re=wd_caviar-_-22-136-513-_-Product

I'll be interested in seeing if they actually end up "bigger" (reporting more logical sectors to the OS) than their competitors.    If you purchased one of these to replace a data disk an existing array, will it be larger than an "equivalent" sized disk (but older) used for the parity disk.  If so, it will complicate the process of replacing a defective drive.

 

Joe L.

If it really does increase the overall capacity by 10% or whatever, then this would have to replace your parity drive in your 1.5TB / disk array.  Does the reallocation of block size create problems for other subroutines, like pre-clearing etc?

If it really does increase the overall capacity by 10% or whatever, then this would have to replace your parity drive in your 1.5TB / disk array.  Does the reallocation of block size create problems for other subroutines, like pre-clearing etc?

Nope, no issue for other processes...  They work on the "logical" blocks reported, which have not been equivalent to the physical sectors for many many many years.

 

As you said, if it shows 10% more space, then if it is bigger than your parity drive, it will have to become your parity drive....  or, you'll need at least two... one for parity and the other data.

 

Joe L.

I'll be interested in seeing if they actually end up "bigger" (reporting more logical sectors to the OS) than their competitors.    If you purchased one of these to replace a data disk an existing array, will it be larger than an "equivalent" sized disk (but older) used for the parity disk.  If so, it will complicate the process of replacing a defective drive.

 

Joe L.

 

I believe I've seen somewhere that they will actually show a larger size, based on the fact tht 512 takes up more space for ECC.  From the Anandtech article "One estimate for 4K sector technology puts this at 100 bytes of ECC data needed for a 4K sector, versus 320 (40x8) for 8 512B sectors".  Multiply this out for a 2TB drive, and it's a considerable gain in usable data space.  If people wanted to upgrade to this, and they were running all 1.5TB drives currently, they'd need to replace their parity drive with one of these first, then replace the rest of data disks. 

 

(also, should we move this discussion to hardware, since I'm sure more people will see it there versus in the good deals forum?)

 

Also, got the follow interesting tidbit as well from http://storagemojo.com/2009/12/21/why-we-need-4k-drives/

 

Will 4k sectors use capacity faster?

If you write 500 bytes and the minimum sector is 4k, will that write take up the full 4k, wasting 3.5 KB? No.

 

The initial WD drives – and I assume other vendors as well – will operate in a 512 byte emulation mode. Eventually new disks will operate in native 4k mode, and then you might have a concern. But many operating systems already do 4k IO. And at a couple of cents per future GB, who cares?

 

 

So what are the real numbers?  What's the usable free space on an EARS 1 TB, 1.5 TB, and 2 TB?

Someone needs to buy one and find out

 

Some people are suggesting the 1TB ones format to 931mb which is the same as a standard 1TB drive afaik.  Since the western digital website seems to make no mention of increased capacity for these drives one would assume we have to wait for a firmware which removes the 512b emulation mode before the additional storage is realised.