SIIG Serial ATA RAID Card problem with Pavilion d4100e

[Jack88]

I have a Pavilion d4100e with the following specs AMD Athlon 64 X2 4200+/ 2GB DDR / 80G SATA Hard Drive.
I recently bought two WD 74G 10K Raptor HDDs and a SIIG Serial ATA 4-channel PCI RAID Card(SC-SA4R12 / use SiI 3114 chip), thought I can have a performance boost by setup raid 0 for these two raptor hdds.
Hardware & software installation went fine, I connected the two raptor hdds to the pci rad card and set them up as raid 0, problem is when I run Sandra 2005 and HDDTach to test the speed of the hdds, they only give me around 60MB/S, that is approximately the speed of one hdd, something wrong with them, so I went to SiliconImage's homepage downloaded and upgraded the bios and the drive of the pci raid card, doesn't help at all, still poor performance.
So I abandon the hardware raid and setup software raid 0 using windows's dynamic disk feature, still give me poor performance, pretty much the same as using hardware raid.
I guess something wrong with this pci raid card or the motherboard, so I only connect one raptor hdd to the pci raid card, and the other raptor hdd I connect it to the sata port built with the motherboard, and setup software raid 0 for these two hdds. Ran Sandra 2005, give me 92MB/S, that is the performance suppose to have. I'm going to use another SATA Raid card see if it has the same problem as SIIG Sata Raid Card, if it still has the same problem, I guess there is something wrong with the PCI bus of the MB(have moved card to different slots, no help). The MB is Asus A8AE-LE (AmberineM).
If anybody have this problem or have experience with this, please help me, thanks!!!

[Jack88]

I have tried a different PCI SATA Raid card, same problem, very slow performance. I guess something wrong with this motherboard. Help!

[Jack88]

nvm, problem found. Asus A8AE-LE motherboard on Pavillion d4100e uses SB400 southbridge does has PCI performance problem.