Pyro installation

[tomaz]

Pyro seems to come as a board, then a piece of foil, a heatsink with a fan, and a metallic clip to hold the fan in place on top of the CPU.

What is the purpose of the piece of foil?

Is it necessary/desirable/not desirable to apply some thermal grease between the CPU and the foil / between the foil and the fan?

[igor_av]

Pyro seems to come as a board, then a piece of foil, a heatsink with a fan, and a metallic clip to hold the fan in place on top of the CPU.

What is the purpose of the piece of foil?

Is it necessary/desirable/not desirable to apply some thermal grease between the CPU and the foil / between the foil and the fan?

If I remember well (based on my experience with overclocking kits for macs), the foil plays the same role as thermal grease, although I'm quite sure it's far less efficient.

[tomaz]

I got my hands on a Pyro which was defunct (it came with a 40MHz 68040 which was dead). I replaced the 68040 with another 40MHz 68040. The Pyro now works but is very unstable (it crashes after a few seconds to a few tens of seconds of usage). The slab it is in has 100ns RAM.

If I understand correctly, the Pyro clocks the 68040 at 50MHz. But AFAIK the 68040 never came in a 50MHz version - it was only available at 25, 33 and 40 MHz.

What to do? Is the problem the slow RAM, or the CPU?

[igor_av]

What to do? Is the problem the slow RAM, or the CPU?

Not all 68040 could be overclocked up to 50 mhz. Also, to attain this range of speed, you need proper cooling : the Quaddoubler I use in my Mac (it has the same function as a Pyro unit) has a peltier junction between the CPU and the heatsink.

If the station boots and works for a few seconds before crashing, my guess would be that the CPU can run at 50 mhz but is improperly cooled.

[tomaz]

The original 68040 40MHz was bust, I suspect, because the fan that sits on the Pyro was not properly fastened to it. After I installed the new 68040, I fastened the fan properly to it. It's now installed as originally intended.

What do you recommend I do to cool it better?

[igor_av]

What do you recommend I do to cool it better?

I'm in no way a specialist, but I'd first check if the heatsink is tightly attached to the CPU. If it is, I'd replace the foil with a small amount of thermal grease (put too much and it becomes an insulant). Also, is there a fan attached to the heatsink? If no, I'd suggest you add one.

These suggestions are based on my own observations of a Sonnet Quaddoubler. Those units are a little different, as they have a peltier junction glued in-between the CPU and the fan-cooled heatsink.

[tomaz]

There is a fan attached to the heatsink and the heatsink is tightly attached to the CPU (with an intervening thermal foil). I'll certainly try the thermal grease idea.

Failing that ... I assume the 68040 in Pyros as delivered are all rated at 40MHz? Surely overclocking them to 50MHz must increase the risk of instability. If I have to get another 40MHz 68040, what are the odds that a random one will work successfully and stably in the long run at 50MHz?

Has anyone had success running a Pyro using 100ns RAM?

[Andreas]

Failing that ... I assume the 68040 in Pyros as delivered are all rated at 40MHz?

You are shure. A safe way is, to aquire a Sonnet Quaddoubler, since they have at 50 Mhz tested units.

[gtnicol]

I posted a few Pyro pictures on Flickr showing the 2 different kinds of Pyro boards I have, and the motherboard modification needed to get the motherboard to boot in slot #2. This modification works without a Pyro, of course, but it is necessary for the Pyro in order to have space for the heatsink.

http://www.flickr.com/photos/15578792@N02/sets/72157628075866757/with/6374434459/




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[nekonoko]

I posted a few Pyro pictures on Flickr showing the 2 different kinds of Pyro boards I have, and the motherboard modification needed to get the motherboard to boot in slot #2. This modification works without a Pyro, of course, but it is necessary for the Pyro in order to have space for the heatsink.

http://www.flickr.com/photos/15578792@N02/sets/72157628075866757/with/6374434459/

Thanks for the photos! I just a got a Pyro and am getting ready to install it in my Cube. Just to be clear, the 5 circled connections in the photo (top row, far right as pictured) are all shorted together? I can't find any mention of this mod in the Pyro manual I have at hand or the scans posted online, and I just want to make absolutely sure before I try anything.

[itomato]

The mod is the same Backplane Trick you'd use to boot up multiple motherboards.

[nekonoko]

Yep, this is supposedly on the board itself rather than the backplane. I'd rather not mod the backplane if I can help it as I have an early/prototype Cube.

[barcher174]

Just an opinion, but maybe it would be better to get a spare backplane to do the mod on?

[nekonoko]

I just went ahead and installed the jumper across the five pins on the motherboard itself as shown in the photo and it's up and running with the Pyro in slot #2. Thanks again for the photo!

[barcher174]

I'd love to see pictures of your setup if you don't mind. Also how did you get your hands on one?