Today I purchased a brand new backup hard drive (2tb Western Digital Elements, USB 2.0) and when I copy files to it from my laptop (Toshiba Satellite l300 with 7200rpm Western Digital Black 500GB HDD) the copy speed decreases over time.
For example, I just copied 25 GB of files to the HDD and slowly the copy speed went from ~30MB/s down to ~15MB/s. This just goes down in small increments over the duration of the file transfer.
The HDD is currently formatted as NTFS.
Here is my crystal mark results:
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s] Sequential Read : 21.475 MB/s Sequential Write : 20.617 MB/s Random Read 512KB : 18.958 MB/s Random Write 512KB : 19.593 MB/s Random Read 4KB (QD=1) : 2.718 MB/s [ 663.5 IOPS] Random Write 4KB (QD=1) : 1.570 MB/s [ 383.2 IOPS] Random Read 4KB (QD=32) : 1.029 MB/s [ 251.3 IOPS] Random Write 4KB (QD=32) : 1.736 MB/s [ 423.7 IOPS] Test : 50 MB [G: 7.1% (131.4/1863.0 GB)] (x5) Date : 2011/11/12 18:56:09 OS : Windows 7 Home Premium Edition SP1 [6.1 Build 7601] (x64)