Adding a cache card

[William Roberts;]

In <1991Jan24.233305.13194 at magnus.ircc.ohio-state.edu> 
talley at hpuxa.ircc.ohio-state.edu (James T. Talley) writes:

>I have some questions about adding a cache card to a Mac IIci
>running A/UX 2.0.  The Mac IIci in question has 8 meg of RAM, 80
>meg internal and 40 meg external hard drives.  It will primarily
>be a network database/mail server.  In other words, no one will
>be using Macish applications on the console on a regular basis.

>1) Is it worth adding a cache card?  Will it enhance the speed of
>   operation significantly for A/UX applications?

A cache card will improve the performance of any program which executes 
smallish loops: an experiment I did with an early version of a cache card 
showed that the IIci with a cache card improved the performance of the 
Dhrystone benchmark significantly: it took the version compiled with A/UX cc 
and no register hints up to the performance of the A/UX cc version compiled 
with register hints (the gcc improvement was even better, though gcc deduces 
the register allocation all by itself without needing the hints). How useful 
it will be if you have no compute intensive applications is hard to say: the 
network database server might benefit from faster instruction execution if the 
tables it searches live largely in memory.

>2) How hard is it to install?  Do I just plug it in?  Will I have
>   to run newconfig?  Do I have to start hacking the kernel with a
>   hex binary editor?  (Just kidding. :-)

It is almost certainly transparent: A/UX already knows about 680x0 cache 
control.

>3) Does anyone have any recommendations on a particular brand?
>   Shall I just buy Apple's?

Buy one you can try out without a commitment to purchase: get the whole system 
working anyway and see if plugging in the cache card appears to make it go 
faster.
--

William Roberts                 ARPA: liam at cs.qmw.ac.uk
Queen Mary & Westfield College  UUCP: liam at qmw-cs.UUCP
Mile End Road                   AppleLink: UK0087
LONDON, E1 4NS, UK              Tel:  071-975 5250 (Fax: 081-980 6533)