[PLUG] SATA2 not faster - was Re: Fixed T60 slow ...

[Keith Lofstrom]

On Mon, Jan 10, 2011 at 10:18:58AM -0800, Keith Lofstrom wrote:
> I expect the SATAII connection will be quite a bit faster,
> since I will be using different buses to stream the data
> from drive to drive.  

Uh ... no.  The SATAII stuff arrived.  While hdparm -t for the
SATA2 interface says 90.7 MB/s, the dd command runs at 50.7 MB/s
with the SATA2 hardware, as opposed to 47.7 MB/s with the Ultrabay
and translator.   So my expectation was false.  Or perhaps there
is a faster way to run "dd" than merely setting the blocksize to
8M (handling the data in larger chunks tends to save time).

Or maybe a newer kernel will help.  I am running an RHEL5.5
clone with the 2.6.18-164.2.1.el5 kernel.  When RHEL6.1 comes
out (RHEL6 just released), that will have the 2.6.32 kernel.  

The Ultrabay and drive weighs 7 ounces, while the SATA2 card
and enclosure and cables and drive weighs 13 ounces.  Sigh. 
6 (fragile) travel ounces to save 10 minutes.  I will stay
with the Ultrabay.

However, the SATA hardware will still be handy for drive copies
when booted from a live CD (the CD drive uses the Ultrabay).
Or if a new kernel breaks the AHCI drivers.  Or if I want to
play a movie off a hard drive.

The brands I ended up with were:

  enclosure:   Eagle Consus M-Series ET-CS2XMESU2-BK
  expresscard: BestConnectivity (SYBA) SD-EXP40014 Sil3132 chip

The enclosure powers from two USB plugs.  It claims to be
"tool-less", but you need to poke into a hole with a screwdriver
or paperclip to open it.  Everything Just Worked after a reboot.  

Keith

-- 
Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs