G-Rex + Voodoo3 + (Heat?) = Very unstable?

[arnljot]

I think the problem is heat.

But first the problem:
- I first installed it, and then it ran fine in about 5+ minutes, and then it hanged. Rebooting would give me 5 new minutes.
- I then superglued a 40x40x10mm fan to the heatsink of the Voodoo3, lifetime was extended from 5 minutes to two hours.

So, what should I do. And secondly, has anyone else had this problem?

I will get those small RAM heatsinks and put them on the RAM of the Voodoo3. But still, I can't understand why a card which is fitted with passive heating gets so hot so fast. Also, I have another Voodoo3, and it has the same problem.

Help is much appreciated!

[new2amga]

Does the G-Rex do 5V or 3.3V PCI slots?  Aren't most new PCI cards 3.3V?  I know some cards are designed to fit in both slots but without a chip to convert the voltage, you may be overvolting the card, causing additional heat to come from the card maybe?

[arnljot]

Its keyed for both 3.3v and 5v operation.

I dont know if my card is 3.3v, but the g-rex is 5v... according to the specs it just says that it supports voodoo3... :-/

good point though, ill look into it.

[amigadave]

new2amga wrote:
Does the G-Rex do 5V or 3.3V PCI slots?  Aren't most new PCI cards 3.3V?  I know some cards are designed to fit in both slots but without a chip to convert the voltage, you may be overvolting the card, causing additional heat to come from the card maybe?

Is the VooDoo3 new enough to be a 3.3volt PCI card?  Seems like they have been made a looooooooooong time ago.

[wawrzon]

ive got voodoo3 in stuffed into a mediator board in an a4k desktop. it is obviously not ment for that. voodoo3 generates tremendous amounts of heat, far beyond what the rest of the setup radiates, including the csppc and the drives. it havent caused a serious system instability though even with a closed housing, but a lot of pixel glitches, always after the machine was up for some twenty minutes. well, i sacrificed one precious pci slot below the gfx card for a huge set of fans blowing the air out of the slot and problem was solved.

[arnljot]

I suspected that the thermal contact between the voodoo chip and it´s heat sink was poor. And I might have been right.

When I removed the heatsink there was only slight traces of contact around the edges of the chip.

I have now exchanged the thermal pad, combined with the fan it might do the trick. I´ll run it through the paces tomorrow.

And yes, it´s like you say, I have to sacrifice a PCI slot beneath it to fit it with a fan.

[arnljot]

Does anyone have a Voodoo3 config for CGX4 that I can try?

I've punched my Lenovo19" LCD data into CGX Mode, but I'm thinking I might be effectivly overclocking it with my settings?

[Kin-Hell]

It's the Voodoo's Voltage Regulator making the Heat Arnljot. Put the active cooling on the Regulator & leave the Voodoo heatsink passive, or actively cool both for enhanced cooling.

If there was any concern @ the difference of 3.3v or 5v on the PCI side of things when using a Voodoo, the Voodoo wouldn't work & you'd either kill the Voodoo for over volting or it wouldn't work for not enough volting. Don't concern yourself with PCI voltages RE PCI Graphic card solutions on Mediators or G-REX's. Just make sure you have the right Radeon model or the right Voodoo model & be sure to set up the G-REX drivers with the correct parameters during the installation process.

Also, make sure your Edge connector off the PPC card is really snug into the G-REX backplane connector. It's best to assemble the PPC card & the G-REX connections first whilst out of the mainboard on the workbench & very carefully align the ZORRO connector & CPU connector whilst gently nudging the whole assembly in place. You should also be using the Processor Card Mobo Stand offs on the G-REX side, so extra care is needed to align these at the same time.

Kin

[x56h34]

The most important thing, is your BPPC card a revision 0 or a revision 2? Revision 0 is not compatible with Grex1200 and even though it might in rare occasions "work", it is highly unstable.

[arnljot]

My BPPC is a CSPPC with Grex and Voodoo3 :-)

[x56h34]

Now you tell me. :-)
You should be ok then, compatibility wise.
Did you install the latest firmware with Grex support, on your CSPPC card?