Overclocking CPUs on TF534

[arkadiusz.makarenko]

At last I have all gear and setup to start using TF534.
I have 50mhz on board with 33mhz CPU.
What would be symptoms of pushing CPU too far? What should I expect?

[8 Bit Dreams]

Black screen, resetting on boot, corrupted screen - i had these issues

[arkadiusz.makarenko]

Black screen, resetting on boot, corrupted screen - i had these issues

Thanks. I had issues running demos. They were throwing illigal instruction and graphic glitches. All was ok on workbench and games.
33 MHz just arrived so swapped it, and all works good now.
I will order 40mhz just for tiny little boost more.

[8 Bit Dreams]

You will be unable to use MMU then, cause 40Mhz are EC versions.
You need a genuine ceramic 50Mhz or 33Mhz CPU to be able to use TF534 @50Mhz

[arkadiusz.makarenko]

I have 33mhz ceramic CPU, but it doesn't like 50mhz, but should be happy with 40mhz oscillator.

If TF536 would get released, then I will be looking for genuine 50mhz CPU.

[8 Bit Dreams]

These are also hard to get, most ceramic cpus sold from China unfortunately are sanded off and reprinted with higher frequency..

[agranlund]

My CPU is rated at 33Mhz and most stuff seem to work at 50Mhz, except for Gembench which crash on startup..
So I run it at 40Mhz and then everything works.

The Gembench crash mentions Line-F. It's a long shot, but who knows, maybe it's not happy at 50 when no FPU is installed.. not really expecting any different results but I will give it another go at 50 once the FPU arrives.

(This is on Atari)

[exxos]

GB6 doesn't care about FPU past checking its installed. I don't think it does much just simple loading GB6. I would suggest running ram test at the higher speeds. Sounds like something is tripping up.

[agranlund]

GB6 doesn't care about FPU past checking its installed

Yes, that was what I suspected. And since the crash happens immediately as Gembench is loaded and becomes visible on screen the long-shot would be that my machine trips up at that check when running at 50Mhz.
I am not really expecting any different results but I'll give it one final go with 50Mhz once the FPU is installed.

In the end, my CPU is rated 33Mhz so 50Mhz is probably pushing it. Everything works perfectly fine and stable at 40Mhz so I am really quite happy with that.

[arkadiusz.makarenko]

What about RAM is there a risk that it doesn't cope at 50mhz?