Re: poor sata performance on 2.6

Konstantin Sobolev
2004-04-15T13:31:37Z

On Thursday 15 April 2004 16:02, Justin Cormack wrote:
> Ah I see from your config you have himem_4G turned on. How much memory
> do you have? Sii3112 appears (I dont actually have datasheets) to only
> have 32 bit DMA support, and will use bounce buffers quite a lot of the
> time if you turn on himem at all, reducing throughput substantially. Try
> again with no himem support at all and see if it helps.

I have 1.5 GB. I tried to disable highmem, now less than 1GB is visible, but
there is no noticable difference in SATA performance:

siimage:
/dev/hde:
setting fs readahead to 8129
setting 32-bit IO_support flag to 1
setting multcount to 16
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 8128 (on)
geometry = 16383/255/63, sectors = 145226112, start = 0
Timing buffer-cache reads: 1428 MB in 2.00 seconds = 713.75 MB/sec
Timing buffered disk reads: 100 MB in 3.03 seconds = 32.99 MB/sec

libata
/dev/sda:
setting fs readahead to 8192
readahead = 8192 (on)
Timing buffered disk reads: 82 MB in 3.02 seconds = 27.17 MB/sec

--
/KoS
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