HOW TO: get a free speed boost from your hard drive

[jonny]

Warning. The advice contained in this How To is risky. It might destroy your system. You have been warned!

Many operations on a PC are I/O constrained. In day-to-day operation, my processor rarely reaches 100%, but my hard drive is often struggling to keep up. But, by default, Hoary doesn't use the fastest possible settings for disk access; it's a little safety conscious. On my newish Dell laptop, these tips speed up my hard drive by 60%, noticeably improving system responsiveness. And nothing's crashed... yet.

First find out how fast your hard drive is. Fire up a terminal end enter

sudo hdparm -t -T /dev/hda

(Change hda for your own hard drive's device number; if you don't know, you're probably not yet ready for this guide). Do this three times, and note the average result.

Now we need to understand the drive's capabilities. Use

sudo hdparm -i /dev/hda

to tell you. If you're really interested, try

sudo hdparm -I /dev/hda

to get more details.

First, look for two settings: MultSec and MaxMultSec. According to the manual, "multiple sector mode, is a feature of most modern IDE hard drives, permitting the transfer of multiple sectors per I/O interrupt, rather than the usual one sector per interrupt. When this feature is enabled, it typically reduces operating system overhead for disk I/O by 30-50%. On many systems, it also provides increased data throughput of anywhere from 5% to 50%." Despite this, you'll probably find that MultSec is off, even if it's supported by your drive, as "Some drives claim to support multiple mode, but lose data at some settings. Under rare circumstances, such failures can result in massive filesystem corruption.

If you're willing to risk it - remember, it may not be wise - enter

sudo hdparm -m <your MaxMultSec value> /dev/hda

Check out your results again, and enjoy the free performance boost.

Now it's time to enable 32-bit I/O. In these days of 64 bit processors, it's a shame to have bits of the system pretending they're in the 1980s - but that's what Hoary seems to do to some drives. Establish the position with

sudo hdparm -c /dev/hda

If the result is 0, you're still in the dark ages. Cross your fingers, and try this:

sudo hdparm -c 3 /dev/hda

It worked for me. A final speed check showed my hard drive was 60% faster - and it felt it, too. But if it blew away your system's brains... I did warn you.

Now all I need to do is work out which config file I have to edit to make this happen at boot time. Does anyone know?

[WMCoolmon]

I can vouch for the second method.

Before:
Timing cached reads: 2020 MB in 2.00 seconds = 1008.64 MB/sec
Timing buffered disk reads: 130 MB in 3.03 seconds = 42.95 MB/sec

After:
Timing cached reads: 2532 MB in 2.00 seconds = 1264.93 MB/sec
Timing buffered disk reads: 148 MB in 3.00 seconds = 49.29 MB/sec

[Technoviking]

This had little effect on my laptop, but laptops are a different animal.

Mike

[vnbuddy2002]

I really suggest against using HDPARM if it is not really necessary. In most of the motherboard, DMA can turn on by using the Bios settings.

The most concern about using HDPARM is the constant system lock up. If you try to copy large files, you will sometimes experience "/dev/hd* time out" and the HDPARM will return back to DMA=off (even DMA is on in your BIOS) and you will stuck with ~1.4Mb/sec. This is one of many factors that causes system lockups.

Good luck! if you insist to try.

[bigzak]

I really suggest against using HDPARM if it is not really necessary. In most of the motherboard, DMA can turn on by using the Bios settings.

My DVD and CD/RW have DMA enabled at boot by most distros, including Warty. Hoary has it disabled, which destroys DVD playback and limits burning to about 16x (52x drive). Quick hack of /etc/hdparm.conf fixes that problem.

[traherom]

This had little effect on my laptop, but laptops are a different animal.

Mike

Yep... not much difference here. Oh well, I had fun typing.

[GameGod]

P4 2.53ghz
ASUS P4T533-C Motherboard
512MB PC-1066 RDRAM
120GB WD1200JB (120 gig + 8 meg cache)

Mult-sect off, 16-bit
Timing cached reads: 2864 MB in 2.00 seconds = 1430.79 MB/sec
Timing buffered disk reads: 90 MB in 3.04 seconds = 29.59 MB/sec

Mult-sect on, 16-bit
Timing cached reads: 2832 MB in 2.00 seconds = 1414.80 MB/sec
Timing buffered disk reads: 126 MB in 3.03 seconds = 41.60 MB/sec

Mult-sect on, 32-bit
Timing cached reads: 2876 MB in 2.00 seconds = 1436.06 MB/sec
Timing buffered disk reads: 134 MB in 3.02 seconds = 44.36 MB/sec

Thanks!
(Nautilus seems a lot snappier, starts a lot quicker too)

[rpaller]

Sorry to resurrect this one, but I figured I would share my findings.

Toshiba Satellite A40 with a Toshiba MK6021 GAS Hard Drive (device manager)

## Test method: sudo hdparm -t -T /dev/hda
MaxMultSect: 16
MultSect: 16
IO_Support: 3 (32 bit)

/dev/hda:
 Timing cached reads:   1872 MB in  2.00 seconds = 935.21 MB/sec
 Timing buffered disk reads:   44 MB in  3.13 seconds =  14.06 MB/sec

Default settings yield these results:
MultSect: 0
IO_Support: 0 (16-bit)

/dev/hda:
 Timing cached reads:   1884 MB in  2.00 seconds = 941.67 MB/sec
 Timing buffered disk reads:   70 MB in  3.05 seconds =  22.97 MB/sec

[HungSquirrel]

I can vouch for the second method.

Before:
Timing cached reads: 2020 MB in 2.00 seconds = 1008.64 MB/sec
Timing buffered disk reads: 130 MB in 3.03 seconds = 42.95 MB/sec

After:
Timing cached reads: 2532 MB in 2.00 seconds = 1264.93 MB/sec
Timing buffered disk reads: 148 MB in 3.00 seconds = 49.29 MB/sec

O_O My drives are incredibly slow compared to yours. Is this normal?

$ sudo hdparm -t -T /dev/hdb

/dev/hdb:
 Timing cached reads:   792 MB in  2.01 seconds = 394.68 MB/sec
 Timing buffered disk reads:  100 MB in  3.00 seconds =  33.28 MB/sec

[vnbuddy2002]

O_O My drives are incredibly slow compared to yours. Is this normal?

$ sudo hdparm -t -T /dev/hdb

/dev/hdb:
 Timing cached reads:   792 MB in  2.01 seconds = 394.68 MB/sec
 Timing buffered disk reads:  100 MB in  3.00 seconds =  33.28 MB/sec

It seems normal to me. The speed also depends on the speed of your hard drive also. Average hard drive speed for IDE hard drives (7200RPM) is ~ 32.00 Mb/sec (on Mode 2 Ultra ATA).