Hello Maurice, Saturday, June 14, 2003, 7:57:23 PM, you wrote: >>I am experiencing a poor sequental write performance with 3-disk RAID5 >>array on 3Ware 7500-8 - it is only 11-12 MB/s. Under Win2000 i get 30-35 MB/s >>from the same array. >> >>Has anybody managed to get good (> 30 MB/s) raid 5 write performance >>from 3ware 7500 on Linux and desktop (non-server) hardware - 32-bit >>33MHz PCI ? MH> Anyway, if you want a better solution, grab mdadm from Neil Brown. MH> Anyway, using that, a 3Ware card, on a 32 bit PCI slot on an NForce2 MH> motherboard with an AMD Athlon XP2500, I see for performance on a 4 disk MH> RAID5 set for sequential block writes between 33 and 40MB/sec, using MH> Seagate (33MB/sec) and WD drives (40MB/sec) Was it 3ware 7500? And what was CPU usage for these writes? And did you try hardware raid5 on it? Thanks for you suggestion but my opinion was that using software raid is a step back in comparison with true hardware raid card like 3ware, especially for raid 5 which is computationally-intensive. Also performance of soft-raid should be lower because data for all N drives (incl. parity) of array should be sent over PCI, and for hardware raid - only data for N-1 drives. Also 3ware cards have features like automatic array validation etc. 3ware claims that their 7500 series gives up to 80 MB/s in 64-bit slot so i was expecting that i got about 40 MB/s in 32 bit slot. In practice i got this (35-40 MB/s) but on _windows_2000_! On Linux i am getting only poor 10-11 MB/s despite the fact that 3ware claims that they fully support Linux! And why buy 3ware card for doing software raid - there are some 4-port software raid cards on the market (like Promise TX4)? MH> I can email you the full report separately if you are interested. would appreciate it very much -- Best regards, Alex mailto:alexver5@xxxxxxx
