Hello, I've just updated our SAN with the last build where irqbalance work properly. No changes had been done to config and I see a performance down in all our dd tests over iscsi. Looking at logs I can see this performance decrease too:

This are the hdparm values before the update:
*-----------------------------------------------------------------------------*
hdparm -t /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:
Timing buffered disk reads: 1682 MB in 3.00 seconds = 560.45 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:
Timing buffered disk reads: 800 MB in 3.02 seconds = 264.71 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdc
*-----------------------------------------------------------------------------*


/dev/sdc:
Timing buffered disk reads: 742 MB in 3.01 seconds = 246.87 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdc
*-----------------------------------------------------------------------------*


/dev/sdc:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdd
*-----------------------------------------------------------------------------*


/dev/sdd:
Timing buffered disk reads: 1576 MB in 3.00 seconds = 524.89 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdd
*-----------------------------------------------------------------------------*


/dev/sdd:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdf
*-----------------------------------------------------------------------------*


/dev/sdf:
Timing buffered disk reads: 544 MB in 3.00 seconds = 181.13 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdf
*-----------------------------------------------------------------------------*


/dev/sdf:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sde
*-----------------------------------------------------------------------------*


/dev/sde:
Timing buffered disk reads: 800 MB in 3.00 seconds = 266.63 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sde
*-----------------------------------------------------------------------------*


/dev/sde:

And this are the ones after the update:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:
Timing buffered disk reads: 1504 MB in 3.00 seconds = 501.24 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:
Timing buffered disk reads: 1556 MB in 3.01 seconds = 516.39 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdc
*-----------------------------------------------------------------------------*


/dev/sdc:
Timing buffered disk reads: 824 MB in 3.00 seconds = 274.56 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdc
*-----------------------------------------------------------------------------*


/dev/sdc:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdd
*-----------------------------------------------------------------------------*


/dev/sdd:
Timing buffered disk reads: 746 MB in 3.00 seconds = 248.45 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdd
*-----------------------------------------------------------------------------*


/dev/sdd:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sde
*-----------------------------------------------------------------------------*


/dev/sde:
Timing buffered disk reads: 284 MB in 3.00 seconds = 94.51 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sde
*-----------------------------------------------------------------------------*


/dev/sde:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdf
*-----------------------------------------------------------------------------*


/dev/sdf:
Timing buffered disk reads: 632 MB in 3.01 seconds = 210.01 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdf
*-----------------------------------------------------------------------------*


/dev/sdf:

Any ideas? Controller is Adaptec 6805. I was expecting the opposite to this situacion.

Regards