Tried to install Promise SX8300 into PCI-64 bit slot. Has to move the current Promise SX4000 to another 32-bit PCI slot. Re-create array for SX4000 gives this error for all Channels: Error Error Event Logged Disk Maxtor 6Y200P0 (Ch. 4, Master) error at LBA 0x17bd87c1 starting from LBA 0x17bd87c1. (Feature=0x0, Block count=0x6, Command=0x20, Status=0x51, Error=0x84. Windows can see the array but unable to initialise or create partition. Tried to move the SX4000 to all other different slots but problem persist. No I/O or IRQ conflict observed. IRQ for this card is not shared too. Please advise how to have both of these cards running in the system. Configuration of system: Tyan 2466MPX-4M with 2xAMD MP2000 Processors 3gb ECC Registered RAM GeCube X800Pro AGP Graphics Card Adaptec 39160 SCSI Host Adapter SX4000 Raid 5 with 4x200gb maxtor hdd Adaptec Firewire+USB2 SB Audigy Leadtek TV2000XP Expert TV Tuner Card New hardware: SX8300 with 2x250 SATA2 WD hdd Thanks.