16mhz mod for ST/STE

[Anemos]

Is there a mod to overclock  my ST-STE's 68000 to 16MHz?
What will be the benefits of it and will it be hard to do it?
In general if there is one, is it worth to make one on my machine?

[ataricrypt]

You might wanna check out Exxos? - http://www.exxoshost.co.uk/atari/

[Anemos]

yes, but is there for STFM / MEGA ST, and not STF / STE..
And, I would like to hear Petari's opinion about this mod.

[Petari]

As I know Exxos has ST version, so for DIL 68000 socket.
I don't have experience with such accelerators.
Overclocking is not possible without lot of other modifications. ST's whole design is based on concrete bus speed, so rising it will make video and other things to not work properly.

Simplest solution is to replace CPU to 16 MHz one, and giving 16 MHz to it only when internal operations are performed. When CPU accessing RAM or some port, ROM clock goes back to 8 MHz.  Only couple chips needed, but average speed gain is only some 20% .

If you can get Mega STE - it has good and efficient solution with cache. Or get MIST. But look first what Exxos offers.

[Anemos]

Thanks for infos petari.
So in conclusion, if I just swap my cpu to a 16MHz one the benefits are almost nothing? Will it just run at 8MHz?
im thinking for MC68HC000FN16 (PLCC)

[DarkLord]

My understanding is that for a 16mhz accelerator to work efficiently, it really needs a good cache.

I have an AdSpeed in my Mega ST and it runs at 16mhz with a cache. The documentation included with the AdSpeed is emphatic about what the cache does. It's very significant.

When you read posts from people experimenting with accelerators over the years, and look at their benchmarks, no cache consistently seems to show a big performance "hit".

Hope this helps.