Dip in ATTO performance... why?

[Charlie98]

I ran a few ATTO tests on my desktop drives today and came away a bit perplexed... Both my boot SSD and 1TB Seagate storage HDD have a dip in performance at around 16KB, the HDD the most pronounced, but my Seagate portable drive, plugged into one of the mobo USB 3.0 ports doesn't... The internal drives are both plugged into the SATA3 headers on the Z68 mobo.

Samsung 840Pro:



Seagate 1TB .12 HDD:



Seagate 500GB GoFlex portable:



I've run ATTO tests before and never got a result like this...

 

[Charlie98]

Any ideas on where to look...? Anyone? I've never encountered this.

 

[mrpiggy]

a. external drive tests through USB are not directly comparable test to on-MB drives because everything is buffered through the USB port/drivers
b. Not all SATA3 ports are equal (i.e. Marvell, others vs Intel) I believe your board only has Intel ports though.
c. Different versions of disk controller drivers yield different results
d. MB BIOS changes can sometime affect results

Generally a dip in one particular area of a disk test that is consistent to other non-identical drives is a driver thing. You should first try different Intel RST drivers and see if the dip at that certain point occurs across all driver versions as that is the easiest to try.

Perhaps try the test on the SATA2 ports to see if the dip is still there (could just be Gigabyte's implementation of the SATA3 ports).