WD raptor too slow

[DUK]

Hi dear all... This is my first post here as I am getting really worried about my knowledges on computer systems...

My system comprises of an ASUS A7V266 motherboard, 1.2Gb ram and an Athlon 1.4GHz .
In my primary IDE channel, i have 2x80GD WD Caviars and in the secondary a DVD and a CD-RW.
I also have a Sil RAID card that mirrors my two 120Gb WD's.
I recently bought a WD raptor 10k rpm HD and along with it a Promise SX40 raid SATA controller with a 128Mb SDRAM on it... installed everything and all went smooth as a baby's butt ...
I decided to run Sandra though to test my HD and see the improvement compared to the old ones...
To my big surprise the rate was... 29MB/s ... while the one in the ATA133 channel did manage 35 ... I installed the latest drivers for everything (VIA, Promise,Sil) and still the same...
The line starts from about 60, then it drops to 25 and stays there till the end of the test having one or two peaks in between. Tried disabling the tagged and queueing commands but still nothing...

Any ideas??

Any help appreciated....

 

[Praetor]

What ATA mode do you have? What RAID config?

 

[DUK]

First of all

three million thanx for answering me Not a lot of people these days do so...

The ATA on the Sil card is ATA33, I presume it is the same on the promise S120 SX40 (but dont know how to look for it... ).
The RAID i am using in the Promise card (where my raptor is connected is JBOD with only one raptor connected on channel 1. I include a benchmark of the selected drive... hope that helps...