Re: DMA or not DMA...

[pubpc1@library.ucla.edu]

spec@vax2.concordia.ca (Mitchell Spector) wrote,
in response to my reply:
>
>>Here are the results of the shift-boot times measured from
>>the moment the "Welcome to the IIgs" screen popped up to the time
>>the Finder appeared.  My copy of System 6.0.1 was installed after the
>>volume had been used for a while, so there was fragmentation.
>> 
>>Time to boot (sec)      with DMA on    
>>------------------------------------  [side snipping]
>>@13.75MHz/16K cache             11                                   
>>@non-Zip speed                  19                      
>
>    That's odd, on my system, which is very close to yours (my Zip is
>1.25 MHz faster with all cache active, but I doubt there is a major 
>significant difference). I get the following:
>
>Time to boot (sec)      with DMA on
>------------------------------------ 
>@15MHz/64K cache                 5
>@non-Zip speed                  11
>
>    Either the RamFAST makes a huge difference or you have a really old
>and slow SCSI hardrive (my past two drives have been 4500 RPMs and have
>had an access time of around 11-12ms). I think my new Seagate drive is
>slightly slower than the Quantum, but I'm getting roughly double the
>performance over your setup.
>
>Mitchell Spector
>spec@vax2.concordia.ca

Probably a combination of a slow drive and the speed advantage of
the RamFAST over the Apple HS SCSI card.

My drive is a Quantum ELS 170MB drive, which was rated among the
slowest, but most cost effective in a MacWorld or MacUser review
a few years back.

I wonder what speed you would get with DMA off and Zip on?
The Apple HS's DMA advantage seems to be paltry compared to the
benefits of Zip speed.

-Scott G.