Nekonomicon - Real Indy scsi speed

marmotta
From Gambolò (Italy)
Who joined April 16, 2005, 1:18 a.m.

Wrote the following at Feb. 21, 2016, 2:23 a.m...

I have Sgi Indy with R5000 and from specs it also have scsi2-fast interface and in theory have a transfer rate of 10MB/Sec

I have connected a very fast Fujitsu Mas3735np (73gb, 15k rpm, U320) with 68 to 50 pin adaptor and works great! But with diskperf I have the speed limited to 5MB/Sec... Sure the scsi controller of Indy is Fast Scsi? Why not go at 10MB/Sec?

dexter1
Moderator
From Zoetermeer, The Netherlands
Who joined Feb. 20, 2003, 6:57 a.m.

Wrote the following at Feb. 21, 2016, 6:33 a.m...

Hi marmotta,

I have diskperf data from an Indy here: viewtopic.php?p=1578

When you scroll down you can see i record data transfer up to about 8.5 MB/sec which is close to the 10MB/sec transfer speed limit of the SCSI bus on the Indy.
Can you post the diskperf data from that fujitsu drive on the Indy? Also the type and model of that disk would be handy.

It might be that your drive needs to be jumpered for Single Ended mode. Also the disklabel has options you can set which affect speed like write buffering and native command queueing, although for simple data reads and writes the latter is not so important.

marmotta
From Gambolò (Italy)
Who joined April 16, 2005, 1:18 a.m.

Wrote the following at Feb. 21, 2016, 12:04 p.m...

This is a screenshot of diskperf and scsicontrol

I have already closed the jumper of "SE"

robespierre
From Boston
Who joined Sept. 12, 2011, 2:28 p.m.

Wrote the following at Feb. 21, 2016, 1:30 p.m...

"Invalid argument" repeated dozens of times isn't clue enough?
/dev/dsk/dks0d1vol is a cooked device, of no use for performance testing. You should be using the raw device (as the man page describes)

marmotta
From Gambolò (Italy)
Who joined April 16, 2005, 1:18 a.m.

Wrote the following at Feb. 21, 2016, 5:03 p.m...

Ops... Now is good

Why with filesystem the limit is 5MB/Sec?

SGI: Hardware

Real Indy scsi speed