Mac Mini G4 Overclock just because its fun.

[aBc]

Especially interesting considering sailorMH’s success with a 1.5 GHz mini… overclocking it to 1.83 (stable). AND the notion that greater overclocks might be possible with more knowledge of voltage / current adjustments (as indibil has now provided). Maybe it won’t be necessary to replace the MC7447B on the 1.5 GHz model minis… WITH adequate voltage / current adjustments?

(However, might still need to change the 1.25 GHz models?)

sailorMH’s translated link again:
https://www-amigaportal-cz.translate.goog/node/156189?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

Still no 1.33 GHz Mac mini example available here.



Thanks for the heads up, Philgood!

[IIO]

how´s the 1.5 a B and the 1.4 an A when the 1.5 is a "silent upgrade" to the 1.4?

[DieHard]

how´s the 1.5 a B and the 1.4 an A when the 1.5 is a "silent upgrade" to the 1.4?

Because apple's definition of "silent upgrade" means...
1) WE are Gods and... we are going to change as much as possible... including the CPU and vRAM
2) WE are Gods and... we are going to document as little as possible... possibly nothing
2) WE are Gods and... may leave the price the same, hike up price for no reason at all (like they did to EU on Mac Pro), or shave off a couple bucks (the rarest choice)

[indibil]

Hello, here I have explained how I managed to increase the voltage and current limit to a Mini. In my case I have done a SWAP with a 1.67GHz MPC7447B and I have reached 1.92GHz, but it can be used to achieve a greater overclock with a stock processor.

https://forums.macrumors.com/threads/g4-7448-and-7457-swap.2233532/post-32783020

Here my blog:

https://rosysumenteinquieta.blogspot.com/2023/12/mac-mini-g4-192ghz.html

[aBc]

"WE are Gods and…"

Reminds me of that movie title - and a great movie too: “The Gods Must Be Crazy”.

And here’s another little example of weirdness.
Stated earlier that there was no example of the 1.33 GHz Mini here.
Well, not my location… but @sonicsky did post an image of his processor.



And if you can make it out from the image, that’s also a “B”.
So are they all “B” except for the 1.42 GHz models?

@snial and @max1zzz (over on 68Kmla) report having 1.33’s.
*1.33’s are only G4 Mac minis with the R52’s absent / stock.

Just when I was almost, finally, going to button-up all minis here.
Have asked @indibil if the MAX1993’s are all set same / each version.

And when he says MAX1993 is “tiny” - he means tiny!

Google translate of @indibil’s blog:
https://rosysumenteinquieta-blogspot-com.translate.goog/2023/12/mac-mini-g4-192ghz.html?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

I don’t relish the idea of changing processors, but I might “adjust” the MAX1993.

AND are the 1.33 and the 1.5 GHz - not Motorola (but "silently" Freescale processors)?

[indibil]

I only have this original Mini at 1.25 and another original at 1.47. I have only measured the values at 1.25.

I have identified the resistors in the photo, I would have to take the tester and measure (with a magnifying glass, hehe)

Adding 330k or 220k in parallel changes the value little, it is not risky.

[aBc]

@sailorMH achieved stable 1.83 GHz with a stock 1.5 GHz processor by changing resistors
(and R52). NOW with the updated, “indibil MAX1993 approach” for voltage / current
increases, perhaps greater than 1.83 GHz (stable) is possible and with a stock 1.5 GHz
processor? Too bad that @sailorMH is off for the holidays and likely not to return until
after the New Year… or we would know more about this much sooner.

Me? I can’t decide if I want to try this on a 1.25 or a 1.5 GHz.
(And I now have a headache!)

@indibil:
And… how about a “final” picture with 330k or 220k in place as it is working now?
*For you to achieve 2.0 GHz - will you need to remove R52 and only have R362 in place?

GREAT WORK! indibil.

[ssp3]

AND are the 1.33 and the 1.5 GHz - not Motorola (but "silently" Freescale processors)?

FYI, Freescale is (was) Motorola.

[robespierre]

The semiconductor division of Motorola. The radio/defense/contractor divisions are still Motorola.
Freescale merged with NXP (formerly the semiconductor arm of Philips N.V.) in 2015.

[indibil]

Hello, i have added a copper heatsink in my Mac Mini 1.92GHz

I attach some pics.

https://rosysumenteinquieta.blogspot.com/2023/12/mac-mini-g4-192ghz-con-disipador-de.html

[DieHard]

Hello, i have added a copper heatsink in my Mac Mini 1.92GHz

Wow, that looks gorgeous !   Can you please explain where you sourced that and if you had to modify it ?   What was the install process ?

[aBc]

Indibil does it AGAIN!

GREAT WORK!!!

He says:
“…now the fan blows more slowly, as it did with the original CPU at 1.25GHz, and the air feels hot. Before changing the heatsink the fan was blowing faster (@1.92 GHz) and the air coming out quickly did not seem to be as hot, although it was.”

My question is - what is the exhaust air temperature measured at the back case opening NOW with the new heatsink and slower fan speed? (Cold boot, no load, at idle…temps taken @10 minutes and @15 minutes?)

Suppose I should make similar copper heatsink for “stock” Mac minis here to check for possible measurable improvement?

We don’t need no stinkin’ CNC!

https://rosysumenteinquieta.blogspot.com/2023/12/mac-mini-g4-192ghz-con-disipador-de.html

[teroyk]

Suppose I should make similar copper heatsink for “stock” Mac minis here to check for possible measurable improvement?

And/or big "hot rod" copper heatsink for tests that would be possible make fanless 1.0 Ghz Mac Mini.

[indibil]

Hello, the heatsink is this:
https://es.aliexpress.com/item/1005004262614951.html?spm=a2g0o.order_list.order_list_main.96.58b1194d3UjeS7&gatewayAdapt=glo2esp

As it measures 50x50mm, I had to cut the width to leave it at 50x40. The height is the same as the original.

First you have to protect the base that have contact with the CPU, I used yellow thermal tape. Using the original as a template, you make the four 3mm diameter holes, and then with sheet metal scissors I cut out the fins in the area of the holes and patiently filed what was left.

I can't measure the temperature, I don't have any reliable thermometer right now, but with the original, and the Mini closed, it blew a lot, with this one, at 1.35v final, it doesn't blow excessively, but it's winter here, it's cold.

I take this opportunity to ask you for help. I have found 32MB VRAM chips like those used in the Mini 1.5GHz, and I would like to change them, but for it to be recognized, I would have to flash the ROM of the 9200 graphics card, but I cannot find any utility for "OSX PPC", nor can I locate in which EPROM it is stored. Maybe it's on the same EPROM as the Mini's BOOT ROM?

Surely there are experts

P.S. I don't know the VRAM speed set on the Mini, but the chips are 300MHz. GaphicAccelerator doesn't show my graphics card speed on the Mini.

[indibil]

I have check with Aticcelerator II and the speed of the VRAM is only 190MHz, but the memory chips is rated 300MHz. It is for reduce temp or reduce consumption?

Rare...

[aBc]

Okay.
No one can offer any insights or possible help here for indibil?

I take this opportunity to ask you for help. I have found 32MB VRAM chips like those used in the Mini 1.5GHz, and I would like to change them, but for it to be recognized, I would have to flash the ROM of the 9200 graphics card, but I cannot find any utility for "OSX PPC", nor can I locate in which EPROM it is stored. Maybe it's on the same EPROM as the Mini's BOOT ROM?

Surely there are experts?

P.S. I don't know the VRAM speed set on the Mini, but the chips are 300MHz. GraphicAccelerator doesn't show my graphics card speed on the Mini.

Pretty please... and with some sugar on it?

[indibil]

Well, it seems that no one is interested in the topic. Well, I bring you some progress. I confirm that it is necessary to flash the graphics card with the appropriate ROM, it does not automatically detect the 64MB. I have changed the VRAM and the image appears undefined. Tested with all 4 chips, to rule out defects. I have re-soldered the 32MB ones, and the image is back.

We need some ATIflash for Mac OS9 or OSX that allows us to download from 1.5GHz and load at 1.25/42GHz. Unless the ATI ROM is stored alongside Apple's Boot ROM, then you will need to dump that content and add it back. I have a TL866 programmer and adapter for that chip, but someone should desolder and read the Boot ROM from their Mini 1.5GHz with a programmer.

edit: It is possible that the 32MB chips instead of the 16MB ones did not work because the original ones are HY5DU283222AF at 2.5V and the ones I put in from the PowerBook are HY5DS573222AF at 1.8V. Perhaps that excess voltage has caused the incorrect operation. Difference between "DU" and "DS", I just noticed the difference.

edit 2: There were some minor graphical glitches, and I thought that by reflowing they would be solved, but my surprise was that after the reflow with the two 16MB chips I now have the same symptoms as with the 32MB chips!! Those 32MB chips came from a motherboard for parts, and perhaps they were damaged, or were damaged when removed, due to excess heat. Soldering memory chips costs much more than a CPU. Now I have found both 16MB and 32MB used chips, but they will take a few weeks to arrive. I have to find out the VRAM voltage because the 32MB ones are still 1.8V and the 32MB ones are 2.5V. Both 300MHz. I would be grateful if someone could provide me with the schematic of the Mac Mini G4: 820-1652-A, because I can't find it.

[indibil]

The ideal would be to find Hynix HY5DU573222F that operate at 2.5V like the original Hynix HY5DU283222F. In the PB there was only HY5DS573222F and on ebay I have only found HY5DS573222F, so to be able to use 64MB of VRAM with those chips it is necessary to lower the VRAM voltage from 2.5V to a maximum of 2.1V. They support a maximum of 3.6V but it is not optimal. I attach screenshots.

I need Mini G4 schematics.

[indibil]

I need the schematics of the Mac Mini G4 for two reasons, first to be able to change the VRAM voltage from 2.5V to 1.8V, although I have a plan B that also requires the schematics.

The other reason is because in the schematics of the iMac G4 I have seen that there are some resistors that by combining 0 and 1 you can choose between the type and amount of VRAM installed, and perhaps the Mini has something similar. If I manage to install the 64MB ones, it may only recognize 32MB without this change.

I mention this in case anyone is interested in joining the project and moving forward.

[Greystash]

I've had a decent search but haven't been able to find anything sorry. Have you tried asking at 68kMLA?