Recenly acquired an external HDD drive in a USB casing speed writing and reading nearly 5 times that of the internal identical 40Gbyte internal drive. How Come?
Bench marks for internal drive:
write 5.57 Mb/s
read 1.85 Mb/s
and for External
20.57 and 13.83 respectively.
DMS (Disk Management System?) may well not be activated - where can I check? - nothing untoward in Device Management as far as I can see.
Removed DMA from primary IDE using PIO resultant bench mark
write = 6.25
read = 1.29
Looks as if DMA not working
UltraDMA mode 5 is stated as normal transfer mode.
( I always return to original settings after testing)
Also tested with no startup programs and no broadband wireless - No Change.
Yes - the quick solution appears to give good results - but the benchmark test returns to PIO mode as does writing a large file/folder to the drive.
It looks as if some interference is occuring in the process of writing to the drive causing the reversion. Shall investigate the more detailed information on http://winhlp.com/WxDMA.htm Thanks
Have exhaustively tried all combinations and suggestions.
The Device manager information reports the current transfer mode as Ultra DMA 5 the memory register is set up correctly.
I am beginning to wonder whether this drive has ever worked in DMA mode or has it always been a dud.?
Thanks anyway for the suggestions - been very interesting.