Western Digital Caviar Black WD2001FASS vs WD1001FALS

Cache is the least important factor in hard drive performance, because all manufacturers include enough cache to buffer as many tracks as are needed to optimize throughput.

The difference in performance between these drives is because the WD2001FASS has higher density platters, which means that in each revolution of the platter it's able to read or write more data. Since both drives spin at the same speed, this means the transfer rates of the WD2001FASS are higher than those of the WD1001FALS.


Sep 14, 2011
I searched the internet and found out
Seagate and WD 1T have 2platter and WD 2T has 4

so does in mean both Seagate Barracuda ST31000524AS and Western Digital Caviar Black WD1001FALS have same transfer rate?
what about Western Digital Caviar Black WD1002FAEX?

I can't decide between them
WD1002FAEX seems to have better reviews but ST31000524AS is much cheaper
PLEASE help me decide
Actually the WD1001FALS has three platters - it holds 334GB per platter while the WD2001FASS holds 500GB on each of its four platters - that's why the larger drive has a faster transfer rate.

It looks like the ST31000524AS also uses 500GB platters so it should have faster transfer rates than the 1TB WD Drive and similar transfer rates to the 2TB WD drive.
Just FYI, Seagate's old model numbering system indicates the number of platters in the second last digit, ie ST310005(2)4AS.

The "5" indicates the cache size.

Be aware that some drives are also short stroked, so even though the platter capacity may be 500GB, the actual data density (and transfer rate) may be that of a 600GB platter.