Gigabyte GA-8KNXP and Promise SX4000 RAID Controller

Having read, and experienced, the lackluster performance of the GigaRAID
with 2 Maxtor 160 GB hard drives in RAID 0, I installed a Promise SX4000
RAID controller with 4 Maxtor 160 GB hard drives in RAID 0 on my Gigabyte
GA-8KNXP motherboard.

First, under Windows XP, it has worked well over the past 7 days, 24 hours a
day. No BSODs at all, but then, I am not overclocking (yet).

I tested RAID 0 and RAID 5 configurations with all types of cluster and
striping sizes, and settled on 32 KB clusters and 32 KB striping. I used HD
Tach, DiskSPeed32 and AIDA. I also read all types of Internet reviews on the
SX4000 in different configurations. I settled on this configuration because
(1) I was looking for overall best performance balance between disk reads
and writes and (2) I backup regularly (so RAID 5 redundancy was less an
issue compared to RAID 0).

In my early testing, I quickly dropped RAID 5 for RAID 0, because of the
difference in write performance. For a RAID configuration of 16 KB striped
and 64 KB clusters, using the Random Write test of AIDA32, the average
throughput for RAID 5 was 10.1 MB/s, vs 52.1 MB/s for RAID 0. Changing to 64
KB striped and 64 KB clusters yielded 10.0 MB/s for RAID 5, but RAID 0
dropped to 38.5 MB/s. CPU utilization was about the same for all RAID
configurations. It should be noted that I am using 256 MB of buffer memory
on the Promise SX4000. 4 Maxtor drives were used in all RAID configurations,
of course, RAID 5 used the 4th drive for parity. In general, read
performance of the RAID 5 was 30% slower than the RAID 0 - again, probably
due to having only 3 hard drives for data verses 4 for RAID 0.

I also did RAID 0 single configuration test with a single drive, to explore
performance against a single drive with the other RAID configurations. In
summary, against the RAID 5, the write speed was the same, but the RAID 5
read speed was doubled.

These results would follow popular thinking about performance between RAID 0
and RAID 5. For those following this thread, I can't emphasize that there is
no fault tolerance in RAID 0 - one drive dies, all data is than loss.
Therefore, religious adherence to backup is a must!

Over the years, I have had considerable experience with SCSI RAID systems at
work. At home, on a limited budget, an IDE based RAID system, such as the
Promise SX4000 and possibly other manufacturer's IDE RAIDs, is a cost
effective approach for RAID performance.

I'll check back here regularly to answer any questions - as best as I can.