Bug 17153

Summary: Qlogic Ultra3 cards seem to write very slow to IBM disks
Product: Base System Reporter: mjacob <mjacob>
Component: kernAssignee: Matt Jacob <mjacob>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: 4.0-CURRENT   
Hardware: Any   
OS: Any   

Description mjacob 2000-03-03 19:40:01 UTC 
The read data rate is quite respectable for these drives:

lorq.feral.com > root lmdd if=/dev/rda8 bs=1024k count=50
50.00 MB in 4.18 seconds (11.9530 MB/sec)
lorq.feral.com > root lmdd if=/dev/rda9 bs=1024k count=50
50.00 MB in 1.90 seconds (26.3304 MB/sec)

The write data rate for the Quantum okay:

lorq.feral.com > root lmdd of=/dev/rda8 bs=1024k count=50
50.00 MB in 3.88 seconds (12.8946 MB/sec)


The write data rate for the IBM totally sucks:

lorq.feral.com > root lmdd of=/dev/rda9 bs=1024k count=50
50.00 MB in 6.80 seconds (7.3521 MB/sec)

Write Cache Enable is not on for the quantum. Setting it for the IBM
doesn't seem to make a difference.

[ I'm filing this bug for myself to remember to look into in a couple of weeks ]

How-To-Repeat: 
See above.
Comment 1 Matt Jacob freebsd_committer freebsd_triage 2000-03-03 19:45:26 UTC 
Responsible Changed
From-To: freebsd-bugs->mjacob

my driver
Comment 2 Matt Jacob freebsd_committer freebsd_triage 2001-10-02 04:59:44 UTC 
State Changed
From-To: open->closed

It may still be an issue- but there's no question that this is a f/w issue- 
in which case, nothing can be done.