Overclocking 3640 board

[Tension]

Can a 3640 be overclocked?  If so, would it just be a matter of changing the crystal?? Can a 060 be installed in it??

Another thread mentions putting an 80MHz 060 on an Apollo 1240...

[tokyoracer]

Can a 3640 be overclocked?  If so, would it just be a matter of changing the crystal?? Can a 060 be installed in it??

Another thread mentions putting an 80MHz 060 on an Apollo 1240...

I have asked about a 060 install on a 040 Commodore CPU board quite a while ago but apparently it isn't possible and even if it was, the design of the 040 apparently strangles it's true capabilities anyway.

As for an overclock, I have no idea how stable it would be and what sort of cooling is requited if it is stable. I will be listening out on this topic.

[Gulliver]

You can overclock the 040 to 33mhz without major problems. Remember that overclcking requires more efficient cooling and a powerfull enough PSU to cope with the xtra requirements. Cooling should not only be applied to the 68040 cpu, but to the chipset on that board too.

If you are really adventurous, and have some really good cooling solutions, you can even go for upto 45mhz. Of course your mileage may vary allways applies, and to reach that amount of overclocking is only recommended for a skilled hacker, not an average user. At this point remember that on 040 and 060 processors the FPU is the one that fails before anything else. So run some FPU tests/apps every time you overclock, to see if you reached a limit.

I still long to see any Amiga based Phase Change cooling for overclocking purposes. I still dream someone may reach with it 100mhz on a 68060 Amiga.


Be carefull and Good luck!

[koshman]

http://members.iinet.net.au/~davem2/overclock/a3640.html

Apparently, it involves soldering a wire between 2 components and also a new oscillator/socket for it.

[HyAmi]

http://members.iinet.net.au/~davem2/overclock/a3640.html

Apparently, it involves soldering a wire between 2 components and also a new oscillator/socket for it.

I've performed this hack, and I must say it works perfect for me. Just to be sure, I swapped the 25MHz 040 for a 33MHz and put an active cooler on it. And while I was at it, I also replaced the capacitors.

So if you want to go for a little hack... this one's recommended.

[LaPTuNa]

Or, If you can find one, a Sonnet doubler 040/50 will work in the a3640. At least it works in mine.

[stefcep2]

I've performed this hack, and I must say it works perfect for me. Just to be sure, I swapped the 25MHz 040 for a 33MHz and put an active cooler on it. And while I was at it, I also replaced the capacitors.

So if you want to go for a little hack... this one's recommended.

I read that you might get motherboard timing issues. and that a trace on the mb has to  be cut?

[delshay]

if i was going to do this project i will use a 68040v ( 3.3v ) to reduce heat.

[Tension]

Or, If you can find one, a Sonnet doubler 040/50 will work in the a3640. At least it works in mine.

There's no trace of this on the internet as far as i can see.  What is it?

[HyAmi]

I read that you might get motherboard timing issues. and that a trace on the mb has to  be cut?

Aren't you mixing up with the infamous INT-2 hack on the A3000? Anyway, I used the upgraded A3640 without problems in my A4000T. At this moment there's only one Zorro expansion card (Elbox FastATA) and it has no problems.

[HyAmi]

if i was going to do this project i will use a 68040v ( 3.3v ) to reduce heat.

I think that's not feasible. The complete circuitry of the A3640 was probably build for 5V only. My guess is (but I'm not an expert) that you'd have to build a voltage regulator for many pins on the processor, both power and data.

On the other hand; please surprise us with a nice project to prove me being wrong!

[Tumbleweed]

There's no trace of this on the internet as far as i can see.  What is it?

its a CPU upgrade board designed for the Apple Mac. You lift out the 040 of the A3640 and fit the Sonnet board in its place. Have a look here:

http://www.welovemacs.com/pr040up.html

Weed

[spirantho]

For what it's worth, hacking the A3640 with a 68060 is kind of like sticking a V8 in a Fiat Uno - mostly pointless. The memory access on a 3640 is so slow that it's being throttled anyway even at 25MHz, in the same way as a V8 Uno with stock fuel system, brakes and drivetrain is still going to be slow.

You're more likely to get crashes with a V8 Uno, though, I'll give you that.

[stefcep2]

Aren't you mixing up with the infamous INT-2 hack on the A3000? Anyway, I used the upgraded A3640 without problems in my A4000T. At this moment there's only one Zorro expansion card (Elbox FastATA) and it has no problems.

No.  Check here: http://members.iinet.net.au/~davem2/overclock/a3640.html

i was at the overclocking workshop Dave refers to above, and yes we had issues with overclocking above 28 mhz, and he did cut some tracks on the MB.

It was may be 8-10 years ago though so i'm a bit hazy on the details.

[HyAmi]

No.  Check here: http://members.iinet.net.au/~davem2/overclock/a3640.html

i was at the overclocking workshop Dave refers to above, and yes we had issues with overclocking above 28 mhz, and he did cut some tracks on the MB.

It was may be 8-10 years ago though so i'm a bit hazy on the details.

Actually, that cut-track-thing of the delay line (as mentioned on that page) is not on the mainboard but on A3640 itself. So if someone had cut tracks on the mainboard, he did another hack/overclock than this one.