Scott Piper wrote:
> Here are my results with -t -T
>
> /dev/hda:
> Timing buffer-cache reads: 1892 MB in 2.00 seconds = 945.67 MB/sec
> Timing buffered disk reads: 172 MB in 3.04 seconds = 56.66 MB/sec
>
>
> and then without options
> /dev/hda:
> multcount = 16 (on)
> IO_support = 1 (32-bit)
> unmaskirq = 1 (on)
> using_dma = 1 (on)
> keepsettings = 0 (off)
> readonly = 0 (off)
> readahead = 256 (on)
> geometry = 65535/16/63, sectors = 240121728, start = 0
>
> and finally with the -i option
>
> /dev/hda:
>
> Model=Maxtor 6Y120P0, FwRev=YAR41BW0, SerialNo=Y3JGZRCE
> Config={ Fixed }
> RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
> BuffType=DualPortCache, BuffSize=7936kB, MaxMultSect=16, MultSect=16
> CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=240121728
> IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
> PIO modes: pio0 pio1 pio2 pio3 pio4
> DMA modes: mdma0 mdma1 mdma2
> UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
> AdvancedPM=yes: disabled (255) WriteCache=enabled
> Drive conforms to: (null):
>
> * signifies the current active mode
>
>
> I'm using kernel 2.6.4 and Debian unstable. It looks like I have
> quite a bit more readahead than you do. The drive has an 8mb buffer.
I'm also using debian/unstable, and I've got kernels 2.4.25 and 2.6.6 on it.
OK, here's mine with the readahead set to 255:
(kernel 2.4.25)
/dev/hda:
Timing buffer-cache reads: 2768 MB in 2.00 seconds = 1384.00 MB/sec
Timing buffered disk reads: 78 MB in 3.05 seconds = 25.57 MB/sec
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 255 (on)
geometry = 14596/255/63, sectors = 234493056, start = 0
--(kernel 2.6.6) /dev/hda: Timing buffer-cache reads: 2624 MB in 2.00 seconds = 1310.23 MB/sec Timing buffered disk reads: 72 MB in 3.07 seconds = 23.47 MB/sec
multcount = 16 (on) IO_support = 1 (32-bit) unmaskirq = 1 (on) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 16383/255/63, sectors = 234493056, start = 0 --
Here's the drive specs: Model=SAMSUNG SP1213N, FwRev=TL100-24, SerialNo=0642J1FWB18403 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs } RawCHS=16383/16/63, TrkSize=34902, SectSize=554, ECCbytes=4 BuffType=DualPortCache, BuffSize=8192kB, MaxMultSect=16, MultSect=16 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=234493056 IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio1 pio2 pio3 pio4 DMA modes: mdma0 mdma1 mdma2 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 AdvancedPM=no WriteCache=enabled Drive conforms to: (null):
So, by increasing the read-ahead, I can get quite a bit of improvement in the buffer-cache read, but none in the disk read. I wonder if the difference between mine and yours (scott's) is due to the udma6/udma5 mode difference?
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