Blade 2000. How can I transfer at 80 MB/s, on 40 MB/s bus ???
Dave
large files (GB) via ftp to a Sun Ultra 27 at about 80-85 MB/s. No compression
is used.
Given the SCSI bus is 40 MB/s
http://sunsolve.sun.com/handbook_pub/Systems/SunBlade2000/spec.html
I find this somewhat odd. The disks are Ultra320 fibre channel disks, which are
not raided in any way. I would thought the SCSI bus would have limited the
transfer rate to somewhat under 40 MB/s, due to overheads.
I've also got a pair of cheap consumer-grade USB disks on the Blade 2000.
Transfer speed of them is limited to about 3 MB/s over the gigabit link (that's
testing on a 200 GB tar file). So clearly the SCSI is output performing the USB,
but I'm surprised how fast the transfer is on the SCSI bus.
Dave
--
I respectfully request that this message is not archived by companies as
unscrupulous as 'Experts Exchange' . In case you are unaware,
'Experts Exchange' take questions posted on the web and try to find
idiots stupid enough to pay for the answers, which were posted freely
by others. They are leeches.
Thomas Maier-Komor
> Since adding a quad Gigabit Ethernet card into my Sun Blade 2000 I can
> transfer large files (GB) via ftp to a Sun Ultra 27 at about 80-85
> MB/s. No compression is used.
>
> Given the SCSI bus is 40 MB/s
>
> http://sunsolve.sun.com/handbook_pub/Systems/SunBlade2000/spec.html
>
> I find this somewhat odd. The disks are Ultra320 fibre channel disks,
> which are not raided in any way. I would thought the SCSI bus would have
> limited the transfer rate to somewhat under 40 MB/s, due to overheads.
>
> I've also got a pair of cheap consumer-grade USB disks on the Blade
> 2000. Transfer speed of them is limited to about 3 MB/s over the gigabit
> link (that's testing on a 200 GB tar file). So clearly the SCSI is
> output performing the USB, but I'm surprised how fast the transfer is on
> the SCSI bus.
>
>
>
> Dave
>
>
Are you sure you are measuring performance of SCSI disks? The Blade 2000
internal disks are FibreChannel, which can for sure transfer 80MB/s.
AFAIK the SCSI bus of the Blade 2000 is only for external devices.
The USB limitation in contrast is most likely bound to Solaris' abysmal
FAT (pcfs) implementation. If you put a UFS filesystem on the USB disk,
you should see much higher transfer rates.
HTH,
Thomas
Doug McIntyre
>Since adding a quad Gigabit Ethernet card into my Sun Blade 2000 I can transfer
> large files (GB) via ftp to a Sun Ultra 27 at about 80-85 MB/s. No compression
>is used.
>Given the SCSI bus is 40 MB/s
>http://sunsolve.sun.com/handbook_pub/Systems/SunBlade2000/spec.html
>I find this somewhat odd. The disks are Ultra320 fibre channel disks, which are
>not raided in any way. I would thought the SCSI bus would have limited the
>transfer rate to somewhat under 40 MB/s, due to overheads.
Doesn't sound like you have anything hooked up to the SCSI bus, so I'm
not sure why you are bringing up the limitations of the SCSI bus in
figuring out your hard drive speeds..
The FC-AL bus is going to be either 1Gb/s, 2Gb/s, or 4Gb/s depending
on age of chipset used, but lets just assume its a 2Gb/s interface
based on the general age of the machine, and that Sun didn't keep up
FC-AL while 4Gb/s interfaces came out, so your bus limitation is more
likely to be 250MB/s.
ie. more than enough to support your supported transfer rate, which
sounds about right to be the max your drives can support.
Dave
Sorry, I'd overlooked the fact that the FC-AL disks are not on the SCSI bus.
They tend to be called SCSI. But then they are not fibre either!
Darren Dunham
> Sorry, I'd overlooked the fact that the FC-AL disks are not on the SCSI bus.
> They tend to be called SCSI. But then they are not fibre either!
If you mean they don't use optical cables, you're correct. But they
are fiber channel disks because that's the protocol used, not SCSI.
They just use the fiber channel protocol over copper cables.
--
Darren
Doug McIntyre
>On Nov 16, 2:55=A0pm, Dave <f...@coo.com> wrote:
>> Sorry, I'd overlooked the fact that the FC-AL disks are not on the SCSI b=
>us.
>> They tend to be called SCSI. But then they are not fibre either!
>If you mean they don't use optical cables, you're correct. But they
>are fiber channel disks because that's the protocol used, not SCSI.
>They just use the fiber channel protocol over copper cables.
Which ultimately are SCSI commands.
But then again, ATAPI and SAS are SCSI commands in the end as well.
Richard B. Gilbert
I don't see why anyone would find this surprising. Regardless of the
interface used, disks are expected to do the same tasks. Would anyone
really want a dozen or two incompatible command sets? Every model of
disk drive requiring a different device driver?
Sami Ketola
> If you mean they don't use optical cables, you're correct. But they
> are fiber channel disks because that's the protocol used, not SCSI.
> They just use the fiber channel protocol over copper cables.
Actually it's SCSI over Fibre Channel over Copper. And if I remember
correctly the interal disks on the Blade 2000 only work 1Gbit/s.
Sami
Richard L. Hamilton
The on-board USB is also 1.1, which is much slower than the 2.0 (12Mbit/s
vs 480Mbit/s, I think). Between that and the horrible FAT implementation,
it's pretty bad. My 2000 has an add-on USB 2.0 which my DVD burner is
connected to (it would have been just about unusable on USB 1.1).