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PB 1400 40MHz Overclock
Posted by: Snial on 2023-10-09 04:57:28
It’s safe to try, but do you know the resistor values for 133MHz operation?

I am planning to overclock crystal 😀
You might be the first person to attempt an overclock on the humble 117MHz module, ha.

I'm sure I won't be the last! PowerBook 1400/117MHz modules are fairly plentiful, because so many people have upgraded them to 133MHz, 166MHz or G3 CPUs. I figure that if th chip itself can handle the higher clock speed (i.e. rated at 117MHz, because they didn't test for 133MHz), then it should still run cooler than a 133MHz module with an L2 cache.

OK, so it'd probably only be a 7% to 10% improvement, but hey, the equivalent of 125MHz or 128MHz would still be a good thing!

Overclock PowerBook 1400/117MHz to Cacheless 133MHz?

I have a PB1400/117MHz module. From what I gather, there was never a specific bin for 117MHz, nor 120MHz, only 100MHz and 133MHz. I went to the PowerPC 603e specifications document from Motorola/Freescale/NXP (https://www.nxp.com/docs/en/data-sheet/MPC603EEC.pdf). On page 24, the PLL_CFG is...
68kmla.org 68kmla.org

It might boost the overall performance of the 1400 to:
PowerBook 1400/11712414392118
(7% boost)13315398126
(10% boost)136157101129

Then the CPU would beat a Performa 6320/120; the FPU would beat a PowerMac 8100/80 my SD based drive would finally get above performance of a PowerMac 6100.

Happy days ;-) !
Posted by: croissantking on 2023-10-09 05:07:18
It might boost the overall performance of the 1400 to:
PowerBook 1400/11712414392118
(7% boost)13315398126
(10% boost)136157101129

Then the CPU would beat a Performa 6320/120; the FPU would beat a PowerMac 8100/80 my SD based drive would finally get above performance of a PowerMac 6100.
I didn’t understand your table. What are the different columns representing?

Even at 133MHz It definitely won’t run as fast as a 6320, I’m afraid, as that machine has 256k L2 cache.
Posted by: Phipli on 2023-10-09 05:17:16
Then the CPU would beat a Performa 6320/120; the FPU would beat a PowerMac 8100/80 my SD based drive would finally get above performance of a PowerMac 6100.
Ignoring a probable better RAM architecture, cache and bus, in terms of raw CPU, a 117MHz should slightly outperform an 80MHz 8100 anyway. The cache and bus benefits will wipe away that advantage, but in pure CPU MIPS, a 603 needs to be about 30% faster to match the performance of a 601.

A 32k cache was a 14% uplift in a IIci, but I forget what it is for a 256k on an 8100 or similar.
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