Messages in this thread | | | Date | Sun, 26 Nov 2000 01:32:55 -0500 (EST) | From | afei@jhu ... | Subject | difference between kernel and bios report on drive status |
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Hi there:
I am using PROMISE ultra100 with 2 UDMA66 disks. The PROMIS bios reports that both disks are using UDMA 4. But during kernel boot On Fri, 24 Nov 2000, Szabolcs Szakacsits wrote: up, the master disk is using UDMA 2 only. The reason is that master disk's pci->dma_ultra value is only 0x40f. I hacked the kernel a bit, both hard disk using hardware configued udma_four though. So I am wondering why not use udma_four as mode indication? Anyone here knows or I have to email Andre on this?
By the way, mode4 works much faster.(hdparm -tT): disk1: udma33, mode2, disk buffer read 14MB/s disk2: udma66, mode4, disk buffer read 24MB/s
both disks: buffer-cache read 88MB/s
The second disk is only 5400RPM, the first one is 7200RPM. Both comply > > HOW? to UDMA66. How come the 2nd one is UDMA66, but the first one is > > > No performance loss, RAM is always fully utilized (except if no swap), UDMA33? And how come the 2nd is faster than the first one.
I hope this is not a kernel bug.
Fei
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