Have one of these?

[flyproductions]

It could be that the thermal paste between the CPU dies and Cube heat plate was disturbed when you adjusted the voltage, which lead to higher temperatures? Did the dies have good contact with the plate? Fresh thermal paste? Did the plate get pretty hot when you had it running in the tower? Or did you use some other heatsink setup?

Yes, this is what i did. I have another card, a PowerLogix Single of which i used the heatsink. It has a nice copperplate to make contact to the dies, spreading over both of them. I checked thermalpaste application twice before everything i did.

fyi, there is a 17x setting (in between 16 and 18).

Yes, this i sure should have tried first. But it appeared to small of a step to me to be worth all the effort.

Also, if you happened to take any good pictures of the back side of the CPU card, I could probably work out what the voltages would be from the labels on the resistors.

Sadly i don't have some at the moment. But i have to strip the mainboard again anyway. So i can make some pics at least of the card's backside. Think i will let the heatspreader in place this time.

To speak of the single card which i use in a quicksilver: Would be more willing to play with this a bit, as it does not need the additional power and would be much easier to replace in case of some "accident". But sadly it lacks SW3. Is there a way to set the voltage by moving or bridging resistors? The card also runs at 1.6 at the moment even beeing sold as 1.7. But - as it is - it never ran this frequency stable. CPU is rated 1.450.

 

[p4ush]

Thanks to @ervus for pointing me to this topic, which I missed in my searches.

Thank you all for the information above.

For what it’s worth, here are the voltages per some of the SW3 combinations, that I’ve measured for my card. Also, a close up of the resistors on the reverse of the card, which are suggested in a post above to be those used by SW3. Finally, a close up of the 7447a.

It is of the same design as the initial photos in the thread. It is the single 7447a version.

Apologies that it is incomplete. Once I reached 1.4 I stopped as that’s the max voltage I’ll need if I do go ahead with a planned 7448 retrofit to this card.

I was already super anxious about having a wire loosely connected to the inaccessible side of a cap under the heat sink, so that was a good excuse to stop!

 

[flyproductions]

Apologies that it is incomplete. Once I reached 1.4 I stopped as that’s the max voltage I’ll need if I do go ahead with a planned 7448 retrofit to this card.

Is there still anybody having 7448s available and beeing able or willing to swap them?

 

[p4ush]

Is there still anybody having 7448s available and beeing able or willing to swap them?

I have a 7448 on a Cisco router logic board that I’m hoping to use - albeit it a SC7448 which I’ve heard someone mention (dosdude I think) doesn’t overclock well.

As for the swap - I have someone in mind but whether he’ll take it on is another story..

The above is just prep work so that I know I can change the VCORE if/when the time comes.

 

[flyproductions]

I have a 7448 on a Cisco router logic board that I’m hoping to use - albeit it a SC7448 which I’ve heard someone mention (dosdude I think) doesn’t overclock well.

Yes dosdude is the only one i heared of doing this kind of swaps. But he is in US and i'm in Germany. Also i do not know if he accepts this kind of "orders" at all.

And it allways comes with the risk of bricking/destroying the card while a dual 4774a would not be that easy to replace these days. So might be the best idea to leave it as it is. 😏

As for the swap - I have someone in mind but whether he’ll take it on is another story..

Is this also US?

The above is just prep work so that I know I can change the VCORE if/when the time comes.

Changing VCORE in my case wouldn't be that much of a problem as i have the SW3 dipswitches.

 

[p4ush]

Yes dosdude is the only one i heared of doing this kind of swaps. But he is in US and i'm in Germany. Also i do not know if he accepts this kind of "orders" at all.

And it allways comes with the risk of bricking/destroying the card while a dual 4774a would not be that easy to replace these days. So might be the best idea to leave it as it is. 😏


Is this also US?


Changing VCORE in my case wouldn't be that much of a problem as i have the SW3 dipswitches.

Yes - sadly I don’t think he does. We need such an expert in Europe!

I’m UK based and the person I had in mind has done some PCB work for me before. I’m sure he does BGA rework too but we’ll see..

My card is a single 1.6GHz 7447a which won’t budge at all with any overclock. The chip itself is marked 1.33GHz.

It’s my second G4 Cube that I’m hoping to put it in. Any such card is limited nowadays and don’t come up often as you know… so I’m kinda on the fence about the risks.

My card does have SW3 also. But I wanted to experiment and work out the voltage configurations before removing the 7447a.

I did try this card in my first Cube for a while but wasn’t overly impressed, primarily because of the 100MHz bus, the limited L2 cache and no L3 cache - at a guess.

I changed it out for a 1.4 GHz 7455 with 2MB of L3. Much better!

So my hope is that the 1MB of L2 in the 7448 would make things better than the 7447a.

 

[p4ush]

Also - originally I did consider using a spare dual 1GHz card I have from a QS 2002.

I thought it would be ideal because it has the extra mounting hole for the 12v feed. I measured the current draw from that point and it was taking ~6 amps. I could use a separate voltage regulator to provide this from the unused second 28v feed from the PSU (I didn’t have any need for ADC).

But gave up when I looked into removing the IDE connector from the logic board for clearance - which means soldering a cable directly to the board.

Although that isn’t the end of the world, it would need some careful planning to implement the extra 40 grounding wires needed for ATA/66 to work as intended.

Life isn’t simple for a Cube!