How far can I push an 040/25?

[lorddef]

Just wondering how far anyone has pushed a 68040 rated at 25Mhz, I know 33Mhz is possible with extra cooling but could one reach 40Mhz or further with a good bit of cooling?

[redrumloa]

Keep in mind 040s run hot normally. If you OC them you will really be pumping out heat.

[Prod]

Over the hill and far away. :-D

[Lando]

Not a chance of hitting 40Mhz - thats like 70% overclock, and 040 if very hot even at normal speed.  30 is good, 33 if you're lucky.

[kzin]

I've had mine to 33 and I herd of 35 but your hard presed to get a 70Mhz cristal round here. Thats with an A3640, but just having ram on the accel gives a better performance boost than over clocking

[AmigaPete]

Depends how tired your arms get...

[Jose]

If you have a nearby electronics store that are willing to solder a new 040 for you on the board for a cheap price, get an 040 at 40mhz. These things go for nothing at eBay.  You'll need a heatsink and fan though, the 040's at 40mhz run VERY hot, even the 40mhz ones.
Or if you're more lucky you'll have one socketed in your board, wich is kinda rare I think.

[jeffimix]

/me hugs his GForce '040 @33MHz (well that's what the seller told me it was, I think the manual says so too...)

[Acill]

I would think the last thing you would want to try is to OC an 040 CPU. They run so damn hot in the first place. You would need some serious airflow to keep it cool, and burning it and/or the accelerator would suck. I would not recomend it at all. You would be better off just getting an 060 accelerator. I'll bet in the next few months if OS4 comes out people will be selling off there classic Amiga to get an Amiga One like crazy if all is working as announced.

[NeRP]

My friend and I both had A4000's.... same revision even.  We took his 3640 card, added a socket, and tossed an 80mhz xtal in it.  He had 40mhz!  Put that same 3640 card in my A4000, and it wouldn't boot until we got it down to 33mhz.  So, we put it back in his machine, and it wouldn't work at 33mhz.

Absolutely bizarre.  It worked though, still works too.  The 040 25mhz made it to 40mhz, and has been running for well over 3 years.  There was only one problem....  the FPU didn't make it.  If you tried to render an image you would get corrupt renders.  For everything else not requiring FPU it ran flawlessly.

[utri007]

040 40mhz can run 50mhz

[A4000Bear]

Years ago I had an A3640 in my A4000, which I later upgraded to a Warp Engine. I purchased the Warp without an 040 and transferred my existing 25MHz 040 into it. I was able to overclock it to 40MHz with perfect reliability. I later sold the Warp to a friend, and it is still running reliably to this day.....at 40 MHz.

I found that 40MHz was the absolute maximum - any more and it would crash. I did try genuine 40Mhz 040s in the Warp and got just under 45MHz.

I used a 486 CPU cooler with fan to keep the 040 cool.

It is also possible to get an A3640 past 33MHz, with an additional cut and jumper mod.

Check out my overclocking site: www.starnet.com.au/davem/amiga.html

David.

[zipper]

Did they use 40 MHz chips in Sonnett Doubler 50 MHz Peltier cooled accelerator cards?

[lorddef]

Cheers peeps.  I'm going to make one hell of a cooler out of some exhaust fans ant attempt 40Mhz, if it frys I'll source a new 040, but I'm sure it'll live.

[Floid]

This is beyond ridiculous, but...

How about a heatpipe-heatsink that can passive-cool a P4?  :-o