Re: [Scst-devel] [ANNOUNCE]: SCST 0.9.5 and Qlogic 2x00-2.6 driver 0.9.5 released

[Mark B. <mar...@gm...>]

So, you're saying that a SCSI card on a 32bit BUS has more bandwidth than a
fibre card on a 32bit BUS? The drive, as measured locally, can do
~52megs/sec read while the initiator only half that.

- Mark.

On 12/18/06, Vladislav Bolkhovitin <vs...@vl...> wrote:
>
> Mark Buechler wrote:
> > I just did some checking. The target is using a 2200 on a 32bit BUS and
> > the initiator is a 2300 on a 32bit BUS. I'll rearrange for the 2300 on a
> > 64bit BUS on the target and see how different that is.
>
> If any of the 2 communicating parties uses 32bit BUS, I wouldn't expect
> much difference.
>
> Vlad
>
> > - Mark.
> >
> > On 12/11/06, *Vladislav Bolkhovitin* <vs...@vl...
> >     Mark Buechler wrote:
> >     >     >>My question is, how can I increase read perfromance? I know
> >     there have
> >     >     >>been threads on performance before but can anyone explain
> >     the drastic
> >     >     >>increase in write and still half on read?
> >     >     >
> >     >     >
> >     >     > Hm, the reads performance on some systems puzzles me. I
> >     considerably
> >     >     > less there, than on the initiator on the same devices. On
> other
> >     >     systems
> >     >     > there is no any noticeable difference. I suspect the reason
> >     could
> >     >     be in
> >     >     > the hardware. Mark, do you use your Qlogic cards in regular
> >     32-bit
> >     >     33MHz
> >     >     > PCI slots? Or in 64-bit 133+MHz PCI-X ones? 32-bit 33MHz PCI
> has
> >     >     maximum
> >     >     > throughput 120Mb/sec, so it will easily kill performance of
> >     sync.
> >     >     reads
> >     >     > (writes are async. and go in batches, so the PCI speed's
> >     influence is
> >     >     > much less).
> >     >
> >     >     Mark, I'm curious, which bus do you use: 32-bit 33MHz PCI or
> >     64-bit
> >     >     133+MHz PCI-X?
>