Looking for PowerLogix PowerForce Overclocking Information

[pipetogrep]

Hi all,

I have a PowerLogix PowerForce Dual G4 1.2 GHz upgrade. Information on it can be found here. I can't find anything on the web about the possibility of upgrading it.

It does have dip switches on the bottom. Has anyone here had experience with this CPU? Any pointers in the right direction would be appreciated.

Thanks!

 

[ervus]

A dual 1.2? Does it look like the picture in the link you sent? They made a few versions.

A manual for the later versions is here:

https://eshop.macsales.com/tech_center/manuals/newertech/maxpower/nwtmang4max.pdf

Also, if you look for a file called MPC7447AEC.pdf you should be able set the speed to what you want.

 

[pipetogrep]

A dual 1.2? Does it look like the picture in the link you sent? They made a few versions.

A manual for the later versions is here:

https://eshop.macsales.com/tech_center/manuals/newertech/maxpower/nwtmang4max.pdf

Also, if you look for a file called MPC7447AEC.pdf you should be able set the speed to what you want.

Thanks for the info. I'll search for MPC7447AEC.pdf. Yes, it looks just like the one in picture I sent except my heat sink is copper colored.

 

[ervus]

What does the actual PCB look like? If there are switches on the "bottom" then it sounds like one of their 7455 CPUs. I think those had two switch blocks, one for each CPU, one on the top and one on the bottom.

 

[pipetogrep]

Also, if you look for a file called MPC7447AEC.pdf you should be able set the speed to what you want.

So I found https://www.nxp.com/docs/en/data-sheet/MPC7447AEC.pdf. This is way above my pay grade. What should I be looking for in there? I've attached a picture of the board with the dip switches on the bottom.

Thanks again!

 

[ervus]

Ok, that picture helps. You have a dual that uses either 7455 or 7457 chips, and it will only fit the computers with a 100MHz bus like the AGP, Gigabit Ethernet, and Cube. The CPU speed is set as a multiple of the bus speed. So if it's at 1.2GHz on a 100MHz bus, then the multiple is 12x. Make sense? Now the datasheet lists all of the options for PLL_CFG. Now look at the table in the MPC7447AEC.pdf and find the entry for 12x, and compare that to the switch block in your picture. See what's going on?

 

[pipetogrep]

Ok, that picture helps. You have a dual that uses either 7455 or 7457 chips, and it will only fit the computers with a 100MHz bus like the AGP, Gigabit Ethernet, and Cube. The CPU speed is set as a multiple of the bus speed. So if it's at 1.2GHz on a 100MHz bus, then the multiple is 12x. Make sense? Now the datasheet lists all of the options for PLL_CFG. Now look at the table in the MPC7447AEC.pdf and find the entry for 12x, and compare that to the switch block in your picture. See what's going on?

I think so. Let me summarize:

100 MHz multiplied by 12 is 1.2 GHz. Looking at the PLL_CFG on page 35, I see that the PLL_CFG column for 12x says '10111' which appears to match the configuration of the dip switches on my CPU.

If that's correct then I should be able to try other configurations based on that info. My next question is, how do I know which configurations are safe? Is there any change of damaging this CPU? I'm guessing I would incrementally set it to 12.5, 13, etc until I encountered instability.

 

[ervus]

Right, you can just try different settings. If you increase the speed it may run a little bit hotter, but I doubt you could actually damage anything unless you also start increasing the voltage. I think that CPU board has a temperature sensor that you can see with CPU Director software. You could check that to get a baseline temperature before trying different settings. Also, as I mentioned there is another switch block on the top side. You might have to remove the heat sink to get at it.

Good luck, and let us know how it goes!

 

[pipetogrep]

Also, as I mentioned there is another switch block on the top side. You might have to remove the heat sink to get at it.

You're right, there are. Now I don't know which ones to try. I guess I'll find out through experimentation. Thanks again and I'll let you know!

 

[pipetogrep]

Here’s the top of the board.

 

[ervus]

Nice CPU! That's a dual 7457 with 2MB of L3 cache. If you wipe the grease off one of the CPU silicon dies you can see markings for what the factory rating is. I'd guess they are marked for 1267, and I'd guess that they would be stable at 1.35GHz and probably more. Also, I doubt you need to worry much about heat unless you're putting that into a Cube. The 7457 uses less power that the earlier chips (assuming the same speed).

 

[pipetogrep]

Nice CPU! That's a dual 7457 with 2MB of L3 cache. If you wipe the grease off one of the CPU silicon dies you can see markings for what the factory rating is. I'd guess they are marked for 1267, and I'd guess that they would be stable at 1.35GHz and probably more. Also, I doubt you need to worry much about heat unless you're putting that into a Cube. The 7457 uses less power that the earlier chips (assuming the same speed).

Thanks! It actually doesn't have L3 cache according to the PowerLogix software and GeekBench. It does have 2MB of L2. I'm still confused, do I need to update both banks of switches or only one of them? They appear to be in the same configuration.

Edit: Here it is with the grease cleaned off.

 

[ervus]

One switch block controls one CPU, and the other switch block controls the other. I'm not sure off hand which is which, but they are independent and don't have to match. For example you could have one CPU at 1.4GHz and the other at 1.35GHz. I would just increase them incrementally together until one CPU gets unstable, then back off one or both settings. If you want to confirm which switches go to which CPU, you can change one setting only and then run CPU Director to see which CPU has a different speed.

 

[pipetogrep]

Success!!! I'm starting at 1.3 GHz and will leave it running for the day to make sure it is stable. Unfortunately, I don't have any kind of temperature monitoring in the PowerLogix software. Before and after Geekbench scores are attached. In summary, that little jump took it from 838 to 897.

Thanks again, @ervus! I learned a lot.

 

[pipetogrep]

Final results. Benchmarks for 1.2, 1.3, and 1.4 GHz.

 

[ervus]

Thanks for reporting your results! It's strange that the L3 cache is not working. Will CPU director let you enable it?

 

[pipetogrep]

Thanks for reporting your results! It's strange that the L3 cache is not working. Will CPU director let you enable it?

Of course! I’m happy to meet people that are into this stuff too.

Here’s what CPU Director shows me.

 

[ervus]

I found what looks like an earlier version of the same CPU. It's a dual 1.2GHz 7457 that fits the 100MHz bus computers. I'm going to try it in a Cube. The L3 cache does show up on my CPU. Did you ever get it working on yours?

 

[pipetogrep]

I found what looks like an earlier version of the same CPU. It's a dual 1.2GHz 7457 that fits the 100MHz bus computers. I'm going to try it in a Cube. The L3 cache does show up on my CPU. Did you ever get it working on yours?

I did not get the L3 cache to show up. That said, I sold that CPU as I found a Dual Sonnet 1.8 GHz. No L3 cache there either.

 

[eyoungren]

I did not get the L3 cache to show up. That said, I sold that CPU as I found a Dual Sonnet 1.8 GHz. No L3 cache there either.

The Sonnets use the G4 7447 chips (the same you find in the Aluminum PowerBooks). The 7447 does not have L3 cache.

 

[ervus]

Nice find! How are you getting these upgrades? How did the two compare? It seems like a dual 1.4GHz 7457 would be pretty close to a dual 1.8GHz 7447. Well, if the L3 was working at least...

 

[pipetogrep]

Nice find! How are you getting these upgrades? How did the two compare? It seems like a dual 1.4GHz 7457 would be pretty close to a dual 1.8GHz 7447. Well, if the L3 was working at least...

I got lucky on ebay. I had a saved search watching for it. I did pay out the nose for it. I recouped the cost by selling the other two CPU upgrades.

Here are some benchmarks:

Dual PowerLogix 1.4 GHz:

Single Sonnet 1.8 GHz:

Dual Sonnet 1.8 GHz:

 

[eyoungren]

I got lucky on ebay. I had a saved search watching for it. I did pay out the nose for it. I recouped the cost by selling the other two CPU upgrades.

Here are some benchmarks:

Dual PowerLogix 1.4 GHz:

View attachment 1815183

Single Sonnet 1.8 GHz:
View attachment 1815175

Dual Sonnet 1.8 GHz:
View attachment 1815177

Right in there: https://forums.macrumors.com/threads/geekbench-score.1706865/page-2?post=22258183#post-22258183

This is from my old QS with the same Sonnet you have.

Post below it shows my result after a SATA card replacement. Why it increased, IDK.

 

[ervus]

Thanks for posting that. It's interesting that the L3 didn't show up, and it is recognized as a 7455. Here is the one I got: