Re: New GS/new accelerator

[Wayne Stewart <waynes@intergate.bc.ca>]

I'd agree with Supertimer that a 7mhz to 15mhz speed increase isn't by
any means a small increase. I'd tend to think the effectiveness of higher
speeds(100mhz) is going to be largely dependent on what the computers
doing.For example viewing or converting a jpeg. Of course it'd help a lot
almost everywhere if the accelerator has a good size cache.
It would complicate things but I always thought a neat way to do it would
be to have a cable running from the accellerator to the memory expansion
slot, That way most of your memory'd be on the accellerator and be
accessable at higher speeds.

Supertimer wrote:

> bobryan9@my-deja.com wrote:
>
> >Apple II accelerator (TWGS)
> >can run at 16 Mhz if you're lucky
> >boosting speed from 2.8 to 7Mhz seems like a big increase when you run
> >programs
> >boosting speed from 7Mhz to 15Mhz seems like a very small increase when
> >you run programs
>
> Not entirely true.  Boosting speed from 2.8Mhz to 7Mhz
> actually seems to have a very modest effect.  Boosting speed
> from 7Mhz to 10Mhz will make things seem much smoother.
> I have a 12.5Mhz TWGS and I can tell you that 12.5Mhz
> seems to smooth things out A LOT compared to 10Mhz.
> Only at 12.5Mhz do things actually seem snappy.
>
> Given the speed curve I've seen with increasing Mhz of the
> CPU, I think that the 25Mhz is probably when you will
> stop seeing much of an increase due to the bus (although
> cached code will continue to increase in speed).
>
> >Apple II accelerators can have a 100Mhz processor, and still be hardly
> >faster than a 15Mhz accelerator, because of the bottleneck of the 1Mhz
> >bus and 1 Mhz video.
>
> Probably 25Mhz is where one would stop and figure it would
> not be worth it to change speeds further.  This is my
> extrapolation based on the differences I've seen while running
> my TWGS at different speeds.
>