Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wasatch!cs.utexas.edu!uunet!virtech!cpcahil
From: cpcahil@virtech.UUCP (Conor P. Cahill)
Newsgroups: comp.unix.i386
Subject: Re: ESDI controller recommendations
Message-ID: <1076@virtech.UUCP>
Date: 26 Aug 89 15:17:19 GMT
References: <121@mdi386.UUCP> <1474@wb3ffv.ampr.org> <4843@looking.on.ca>
Organization: Virtual Technologies Inc
Lines: 20

In article <4843@looking.on.ca>, brad@looking.on.ca (Brad Templeton) writes:
> Surely it makes more sense for the OS to do all other cache duties.
> Why put the 512K in your drive when you can put it in your system and
> bump your cache there?   Other than the CPU overhead of maintaining the
> cache within the OS, I mean.  I would assume the benefit from having
> the cache maintained by software that knows a bit about what's going
> on would outweigh this.

A big benefit is that the memory used for disk cacheing is not part of the
standard system memory therefore my 33Mhz 386 can have 16 meg of memory and
my disk controller can have 512K-12meg of disk cache. 

Another point would be raw devices which are not buffered by the kernel but 
are cached by disk controller.

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| Conor P. Cahill     uunet!virtech!cpcahil      	703-430-9247	!
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