Hi Bob: You have a number of options if you are really IO bound and you are doing large sequential reads/writes (and not random reads/writes): 1) RAID0 (striping): This can get you near to the theoretical max performance out of the bus the drive controller is attached to. In the case of IDE controllers on the motherboard, the best you typically could do would be 133 MB/s, though I have not seen more than about 110 MB/s sustained sequential large block reads across a 2 way stripe. With a PCI-X based controller card and enough SATA drives, you could get (theoretically) 12x55MB/s or about 660 MB/s (for a 12 way stripe across SATA). You would be limited by your DMA and interrupt rates. You could also do this with SCSI, just for a great deal more money. Note: FC will buy you at most 200 MB/s, so FC connected disk is not better than a 3ware card (actually worse, as the 3ware will give you in the best case, about 600 MB/s). U320 based SCSI will top out at 320 MB/s. 2) create a large ram disk: You have to have enough memory for the ram disk, the disk cache, and enough room to compute with. This is relatively inexpensive compared to other solutions, and would give you GB/s access to your data. If you are stuck doing many random rw operations, you might need to get the SCSI disk which handles the random rw better than SATA. If this is across a cluster of machines, and you need to distribute the computations with the data, you might look at Panasas disk. I have used them in sustained 1.2 and 1.6 GB/s work across some sizeable Linux clusters. Joe bob sandefur wrote:
Hi- Does anyone have any experience if a scsi dirve on a PCI card is faster than IDE with 9.2 SUSE? If so how much faster and what PCI cards and scsi drives are you using? I am reading and writing a 0.5 gb geological model multiple times and seem to be IO bound Thanx Robert (Bob) L. Sandefur PE Senior Geostatistician / Reserve Analyst CAM 200 Union Suite G-13 Lakewood, Co 80228
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