I know there are a few 3Ware fans here and I was hoping to find some help. I just built a new server using a 3Ware 9550SX-4LP with four disks in raid 5. The array is fully initialized but I'm not getting the write performance I was hoping for -- only 40 to 45MB/Sec. 3Ware's site advertises 300MB/Sec writes using 8 disks on the PCI Express version of this card (the 9580 I think.) I'm guessing 4x PCI Express has more bandwidth but 133Mhz 64-bit PCI-X is no slouch. The only two things I need to change are to put the disks in 3GB/Sec SATA mode (they're in 1.5GB/Sec mode right now) and to enable memory interleaving on the motherboard (I only have two sticks of memory, this M/B needs 4 for interleaving.) But I don't think these things should drop me down to the write performance of a single IDE disk. Does anyone have any suggestions on improving write performance? The Details (I know the devil is in here somewhere): Supermicro X7DVL-E Motherboard Dual Xeon 5130 (2 Ghz) 2GB RAM 3Ware 9550SX-4LP in a 133Mhz 64-bit slot. 4x Seagate ST3400620AS 400GB SATA Drives NCQ Enabled but currently in 1.5GB/Sec mode CentOS 4.4, Kernel 2.6.9-42.0.2.ELsmp Stock Kernel 3Ware Driver 2.26.04.010 Bonnie++ 1.03a 50GB Benchmark run four times on an ext3 filesystem: ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP Beryl 50G:64k 44572 77 53084 14 40624 7 47790 72 162504 12 96.5 0 Beryl 50G:64k 45960 79 53068 14 39972 7 47701 73 162510 12 96.8 0 Beryl 50G:64k 36846 64 37579 10 36785 6 48090 72 162609 12 96.9 0 Beryl 50G:64k 45205 77 53621 15 40757 7 48325 73 162331 12 96.4 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP Beryl 16 3928 99 +++++ +++ +++++ +++ 3961 98 +++++ +++ 12442 99 Beryl 16 3929 98 +++++ +++ +++++ +++ 3957 99 +++++ +++ 12373 100 Beryl 16 3718 94 +++++ +++ +++++ +++ 3389 84 +++++ +++ 12307 99 Beryl 16 3920 98 +++++ +++ +++++ +++ 3969 99 +++++ +++ 12421 99