Hello
I am developing a type of SATA HDD and its also using a SATA<>USB 3
converter for easy use/test with a PC.
The drive is working, but I have tripped across a couple transfer size
issues.
When the drive connects to a Windows8 PC, it identifies as a UAS compliant
device. I can change this in the descriptor that is provided by the
SATA<>USB3 converter
My understanding is that the UAS device uses the UASPSTOR.sys driver. My HDD
also identifies as a 4K physical and 4K logical sector drive. During
operations, the driver/PC communicate in groups of 128 4k sectors, or 512KB
per transaction.
I want to increase this to groups of 512 4k sectors or at least 256 sectors.
How can do I this?
I found that in Windows7 only the USBSTOR.sys is used and there was a
registry/hotpatch that allows the user to specify a MaxTransferLength field
of upto 2MB, which would get me exactly the 512 4k sectors that I want.
In my Windows7 testing, I was only able to get 256 sectors - which is OK,
but I’d like to get 512 sectors.
So, is there a way I can increase the transfer length for a UASPSTOR driver
in Windows8?
Has someone verified that in Windows7, you can actually set a 2MB transfer
length and get a 512 4k sector transfer?
If I disable UAS mode on my SATA<>USB3 hardware , will the USBSTOR.sys
driver on Windows8/10 accept the MaxTransferLength patch in the registry so
I can also get 1MB to 2MB transfer sizes in Windows8/10
Thanks!
-Steve Spano
Finger Lakes Consulting, LLC
224 West Lake Road
Dryden Ny 13053
607-844-8505 x223