exxos's Atari, Amiga & retro forum

Howdy

I noticed that most TF536's have 68030's that are overclocked to 50mhz, not got a problem with that, it's super stable. But my thinking was, and maybe I'm a right eejit, but if you dropped, say. a ceramic 030 rated @ 50mhz, could you then overclock that CPU higher? maybe 55 or 60mhz? or would the logic glue go wonky, and the memory start going off it's nut?

thanks

duncan.gibb wrote: 28 Jul 2020 22:27 Howdy

I noticed that most TF536's have 68030's that are overclocked to 50mhz, not got a problem with that, it's super stable. But my thinking was, and maybe I'm a right eejit, but if you dropped, say. a ceramic 030 rated @ 50mhz, could you then overclock that CPU higher? maybe 55 or 60mhz? or would the logic glue go wonky, and the memory start going off it's nut?

thanks

@snifferman is playing with overclocking of TF536.

Personally I can't see any benefits of this. Increase in performance would be minimal really. But I am curious how far it can go and work stable.

is that, "yes" ?

duncan.gibb wrote: 28 Jul 2020 23:03 is that, "yes" ?

Yes but just few Mhz, only possible with very few - expensive these days - 030 cpu versions. Practically no one really does it.

Isn't the 7mhz clock constructed from the 100mhz osc ? If so upping the speed will cause sync issues I think.

Isn't the 7mhz clock constructed from the 100mhz osc ?

Yes, but there is a small margin where it will still work.
I can tell only from testing that:
-108Mhz(10.74mips) works fine by me without IDE buffers. With buffers i had IDE dettection problems, and had to reset the Amiga to boot from SD. Maybe it`s a problem with SD-IDE Adapter- I had it on some A1200 board revisions too. CPU 36*C

-110Mhz(10.94mips) Had problems with IDE interface. Accessing data from SD card amiga was frezzing once in a while. Frotnier demo was working for several hours. I finished 40h render in LW3.5. CPU 38*C

I soldered a new card using XC95288XL-7TQG144C and made tests:

-120Mhz(11.95Mips) After changing firmware to https://www.exxosforum.co.uk/forum/downl ... p?id=12821 tf536r2_2020_07_20b_alpha.zip no IDE problems spotted. During stability testing. LightWave 3.5 render runs 27h and is expected to be finished in next 7h. CPU 39*C

125Mhz(12.44Mips) Unstable. Was able to run sysinfo test, and play around for 30 minutes. Not tested with alpha firmware- Waiting for finish 120Mhz tests.

All test done without heatsink or Fan.

The 030s simply do not work past 55mhz. There is very little point in over clocking them much.

The 536 is optimised for 50Mhz fixed frequency but the 7mhz clock will be a little out of phase with a 110mhz clock. Might see random rare crashes.

My opinion is just don’t do this.

The 030s simply do not work past 55mhz. There is very little point in over clocking them much.

Well it depends how you look on it. Now days it does not have any practical sens. In the past however rendering many 3d frames can take days/weeks on 030. 10% more speed could save you days.If it was unstable you lost days.

Im not using amiga for work or i do not keep important data on it. I can fry cpu however so its still risky game to play.

For normal use - better stick to most stable 50mhz setup.
Like i said im just checking render time of the same frame with diffrent clock speeds to campare it.
I manage to finish this render on 108mhz,110mhz and 120mhz will be finished today if it won't crash.

For getting a bit more out of a renderer i'd probably be looking at an 040/060 solution. The TF series is really aimed at gamers and nostalgic use of older applications rather than serious productivity.

I was talking about the past when 060 was out of range for average amiga user/hobby scene maker.

I have 060 on my A1200, but somehow soldering and testing brings me more fun. Pushing 030 to the limit is also exciting.

Amiga hardware is hobby for me and maybe a way to learn something about electronics.