"Jan Vesterlund" <jv@danlamp.dk> wrote in
news:ah45i1$7be$2@sunsite.dk:
> Jeg har 3 Maxtor 740 (40Gb) og den ene kører jeg systemfiler mv.
> på og de andre 2 skal bruges til videofiler.
>
> Mit bundkort er MSI 845 Ultra (MS-6398) med ATA 133 RAID onboard.
> Mit problem er at når jeg arbejder med video virker det meget
> bedre hvis jeg bruger disken til system i stedet for de to i RAID
> 0.
>
> Jeg kan ikke capture mere end 20 sek. uden at tabe billeder og
> harddiskene arbejder meget. På systemdisken kan jeg capture op til
> 30 minutter uden tab af billeder.
>
> Kan det være en fejl i opsætningen? Jeg har valgt autosetup og
> valgt "performance" og "A/V Editing".
Prøv at tjekke om din cluster size og stripe size er sat op som
nedenstående.
(
http://www.overclockers.com.au/techstuff/a_hdd_shootout/page2.shtml):
RAID 0 block stripe size:
Users report generally best results with a 16K or 34K stripe size.
Anything above 34K seems to reduce performance and is not recommended
unless the array is used for working with exceptionally large files
such as in video editing.
File cluster size:
It seems that for usual desktop tasks the Maxtor D740X performs
slightly better when the file system is formatted in 34K clusters. The
Western Digital JB series seem to prefer 16K or even 8 K. We have
tested the 1000JB and the 120GXP in 8K/16/ and 32K and found only
random differences. It seems that a RAID 0 stripe size of 16K and a
file cluster size of 16K is the best overall compromise for desktop
jobs. We used therefore a 16K stripe size / 16K cluster size combo for
our tests. User who have only 2 disks available and wish to format
their RAID 0 array which contains the OS with an other than the default
size of 4K in NTFS will find here a how-to-do.
PCI latency:
Already a while ago it was discovered that VIA chipsets have obviously
a problem handling the increased burst speed of high-end ATA disks.
They start to interrupt the burst shortly after the cycle has started.
These interruptions taking place every 1.2 µs reduce transfer rates of
high-end ATA 100 and ATA 133 disks. An in-depth explanation can be
found here at techchannel.de which discovered the issue shortly after
boards with the KT266A chipset started retailing. In particular for
optimal RAID performance with VIA chipset it is necessary to lower PCI
latency. This can be achieved by patches lowering the PCI latency for
the devices attached to the PCI bus by making adjustments to the chip
that manages the PCI bus. VIA is offering a "Raid Performance Patch"
here. There is also a non-VIA PCI latency patch, named after the
author, "Breeze patch" available here. Both patches increase the disk
transfer rate by approximately 10 MB/sec. According to many users and
our own results the Breeze patch is performing slightly better than the
VIA "RAID Performance Patch". We used for our tests version 1.9d of the
Breeze patch.
Mvh
Flemming