[PlanetCCRMA] tuning disks with /dev/sda SCSI drives

[Mark Knecht]

On Fri, 12 Nov 2004 11:07:26 -0800, Noah Garrett Wallach
<logic at enabled.com> wrote:
> On Fri, 12 Nov 2004 09:25:09 -0800, Mark Knecht wrote
> > start with hdparm -tT to get some speed info. Look at interrupts
> > also. cat /proc/interrupts and cat /proc/irq/...
> >
> 
> Mark,
> 
> Okay the CCRMA documentation appears to be IDE-focused.  I am not sure what to
> do with this data?
> 
> --- snip ---
> 
> [root at dhcp-178-1-168-192 root]# hdparm -tT /dev/sda
> 
> /dev/sda:
>  Timing buffer-cache reads:   3164 MB in  2.00 seconds = 1583.03 MB/sec
>  Timing buffered disk reads:  166 MB in  3.00 seconds =  55.30 MB/sec
> [root at dhcp-178-1-168-192 root]# hdparm -tT /dev/sda
> 
> /dev/sda:
>  Timing buffer-cache reads:   3432 MB in  2.00 seconds = 1718.84 MB/sec
>  Timing buffered disk reads:  168 MB in  3.03 seconds =  55.53 MB/sec
> 
> [root at dhcp-178-1-168-192 root]# cat /proc/interrupts
>            CPU0       CPU1
>   0:    1018635     980361    IO-APIC-edge  timer
>   1:        525        625    IO-APIC-edge  i8042
>   8:          1          0    IO-APIC-edge  rtc
>   9:          0          0   IO-APIC-level  acpi
>  14:       1243       1009    IO-APIC-edge  ide0
>  15:      16536       2635    IO-APIC-edge  libata
> 169:      60338      58591   IO-APIC-level  uhci_hcd, uhci_hcd,
> radeon at PCI:1:0:0177:          0          0   IO-APIC-level  uhci_hcd
> 185:          0          0   IO-APIC-level  Intel ICH5
> 193:      27080          0   IO-APIC-level  uhci_hcd, eth0
> 201:          2          0   IO-APIC-level  ehci_hcd
> 209:          0          0   IO-APIC-level  rme9652
> NMI:          0          0
> LOC:    1998918    1999095
> ERR:          0
> MIS:          0
> [root at dhcp-178-1-168-192 root]# cat /proc/irq
> cat: /proc/irq: Is a directory
> [root at dhcp-178-1-168-192 root]# ls /proc/irq
> 0  10  12  14  169  185  2    209  4  6  8  prof_cpu_mask
> 1  11  13  15  177  193  201  3    5  7  9
> [root at dhcp-178-1-168-192 root]#
> 
> --- snip ---
> 
> cheers,
> 
> Noah
> 
> 
>
I don't think you need to do much at all. You're getting 55MB/S from
your expensive SCSI drives. From that standpoint you're in like Flint.
However, I guess I'm blind but I'm not seeing aninterrupt for your
SCSI controller. Is there one?

The only other thing you'll want to consider down the road a bit is
whether you have the right kernel and how much control you have over
threaded or non-threaded interrupts for your sound card.