neese@adaptx1.UUCP (05/16/91)
>/* ---------- "aha-1542b running at 8Mhz DMA on No" ---------- */ >The 1542b is capable of the follow DMA transfer rates: 5Mhz, 5.6Mhz, 6.7Mhz, >and 8Mhz. I experimented with a Quatum 210s in synronous mode and was >only able to run at 6.7Mhz. I tried an 8Mhz DMA transfer rate and was >unable to boot. The CPU claimed 'parity error' at some segment ( I forget >the actual segment ). > >Everything seems to be peachy running at 6.7Mhz. Is this a problem with >the Q210s? Is it a problem with the motherboard? No problem here. You have just reached the memory transfer rate limit of the motherboard. Running at 6.7MBytes/sec is much faster than the SCSI bus will run, so you are not loosing anything. As a matter of fact, this transfer rate is really an ideal one. Allows the SCSI device time to keep the data flowing while minimizing disconnects. Running faster can cause more disconnects and thus reduce the overall performance of the SCSI subsystem. This is largely dependent on the device. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese