What is the differance between the WD3003FZEX & WD3001FAEX

I’m looking at upgrading some of my smaller Black drives to there 3TB Blacks, however when looking at there spec sheet here
http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771434.pdf

It seems there is a tiny difference in write speed (which does not bother me much) but it does mention “Advanced Format (AF)” which if i remember right was something to do with 4k sectors but given i’m running win 7 U x64 i guess this does not effect me, however i do run “Acronis True Image” every day from it’s boot CD and may well clone " TOO" these AF drives, never from them only TOO , any advice is welcome before i take the plunge.

All1

Here is an explanation of the advantages of the AF technology:

About Western Digital Advanced Format Hard Drives

http://www.wdc.com/global/products/features/?id=7&language=1

The specs for both 4TB models are identical. http://www.wdc.com/en/products/products.aspx?id=760

TIA,

I belive not all the specs are made public. A diference between this drives could be in the platters. The WD3003FZEX seems to have 800GB  per platter, not sure about the  WD3001FAEX. And more recently are the ones with 1TB per platter which seems to  perform a bit faster from what i have read in forums.:joy_cat:

The WD3003FZEX seems to be a new version of the WD3001FAEX.

Check this link:

www.newegg.com/Product/Product.aspx?Item=N82E16822236424