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Re: Sun Blade 100 vs Ultra 60

On Mon, Feb 11, 2008 at 09:40:35PM -0500, Rafal Boni wrote:
> Heh, having used the CMD646 in the Ultra5 for disk access, I have one 
> word: "ewwwww".  Maybe the chip used in the T1/105 is a newer rev, but 
> the U5 got abysmal disk performance (due to UDMA being disabled to work 
> around a chip bug, AFAIR) when using the on-board CMD646.

IIRC it isn't a 'bug', but there is only one dma channel through the
device shared by all 4 possible target devices.
The original design of Tadpole's 'voyager' (not to be confused with
sun's one) used 4 646's - one for each disk.
Those worked fine - but didn't have to handle big disks!


David Laight: david%l8s.co.uk@localhost

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