Messages in this thread | | | Date | Wed, 02 Jan 2002 15:23:38 -0500 | From | Brian <> | Subject | Re: Two hdds on one channel - why so slow? |
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On Wednesday 02 January 2002 02:31 pm, Andre Hedrick wrote: > Brian, > > This was true in the past and with many older drivers. However when and > if the new driver I have is adpoted, it will make SCSI cry. So please > stop polluting the issue.
Both the master and the slave may have requests in progress at once now? This is the first time I have heard that issue refuted. In fact, we just bought an 8-drive 3ware 7800, with 8 channels and 8 cables, that seemed to further confirm that issue.
> Now I have managed to use two hosts w/ 4 channels no caching controller, > no hardware raid, 4 7200RPM drives and software raid 0. I was able to > push 109MB/sec writing and 167MB/sec reading.
So each drive was a master on a chain to itself? I am not denying the performance of this setup. Also was this on the above hardware (the read speed would exceed a PCI 33/32 bus)
> Also under a similar environment, I was able to, using a single card, 4 > drives, not hardware-raid, no caching controller, reach 90MB/sec writing > and reading was about 78MB/sec.
4 drives on two chains (master & slave on each) is certainly more interesting. The write speed is impressive, but what cut the read performance in half?
> Now lets adjust cost of componets and SCSI loses big.
Indeed. That 720GB file server totaled ~$3000.
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