Replacing CPU in gamecube

[kinect360]

tueidj +1 again for him. I have the n64 overclock mod on my n64 and it works great. If the same type of setup could be achieved for the gamecube just for testing right now would be great.

[APE992]

BUT:

Games are running faster on a XBOX with higher CPU!!!

I own one!
128MB RAm and 1GHZ CPU -> Games are faster then with 733MHZ!
I think this would be the same Prob here!!!

That's because some games are coded in ways that bump up against the limitations (I'm looking at you, Halo 2). Most GameCube games weren't.

This thread is great for some laughs. It'd be great if we could overclock the cube but I'm doubtful we'd see much use for it.

[iamdablasta]

This thread is great for some laughs.

:'(

I'm doubtful we'd see much use for it.

Muh emulators, much clock speed (see clockspeed attachment for visualisation of faster clocks).

clockspeedjoke.png

(587.6 KiB) Not downloaded yet

Jokes aside, My opinion (while not of high value) is something I stand for. It is a worthy cause.

[megalomaniac]

And here: pinout with mark (red PLL, green SYSCLK) Gotta check where they are on the motherboard later so we could hopefully overclock without any desoldering of the chip.

if overclocking could be performed without desoldering the CPU, dont you think it would have been done already?
...and with the researched performed from wii developers, dont you think its been proven to have no benefit for overclocking or CPU swap??

[iamdablasta]

dont you think its been proven to have no benefit for overclocking or CPU swap??

I haven't seen any concrete proof, but give me some and I'll give up this second.

[werejag]

required werejag post in before the close

[tueidj]

dont you think its been proven to have no benefit for overclocking or CPU swap??

I haven't seen any concrete proof, but give me some and I'll give up this second.

Go find any youtube video of GC games being run under Devolution, which keeps the wii's CPU running at full speed (729MHz).

[iamdablasta]

dont you think its been proven to have no benefit for overclocking or CPU swap??

I haven't seen any concrete proof, but give me some and I'll give up this second.

Go find any youtube video of GC games being run under Devolution, which keeps the wii's CPU running at full speed (729MHz).

But games are often limited to a certain speed. Wii64 doesn't even reach full speed on gamecube, but does good on a few games (note, few) on the wii. Whether this is due to programming or pure power I don't really know, but it could very well be a mix of both.

I'll look more into devolution later, but doubt it is giving information I am looking for.

[tueidj]

So then overclocking the CPU is just going to screw up the rest of the system, since operations that are expected to complete in X cpu cycles will actually take (overclock_ratio*X) cpu cycles.
As an example:
The bus clock (used as the frequency that drives the CPU's timer/decrementer) on a gamecube runs at 40500 ticks/ms.
So if a game expects a DVD read to take a maximum time of 1ms, the decrementer is set to 40500. When the DVD read finishes successfully the decrementer gets "cleared". But if the read doesn't complete the decrementer value reaches zero and throws an exception, a disk read error is assumed and the game halts.
If the CPU is overclocked the decrementer will count down faster than expected, for example on wii the bus runs at 60750 ticks/ms so it will only take 0.6667ms to count down from 40500. Games won't be aware of this so they will still assume the bus clock is 40500 ticks/ms and program it based on that value. This means the decrementer will count down faster than expected causing incorrect timeout errors.

[iamdablasta]

So then overclocking the CPU is just going to screw up the rest of the system, since operations that are expected to complete in X cpu cycles will actually take (overclock_ratio*X) cpu cycles.
As an example:
The bus clock (used as the frequency that drives the CPU's timer/decrementer) on a gamecube runs at 40500 ticks/ms.
So if a game expects a DVD read to take a maximum time of 1ms, the decrementer is set to 40500. When the DVD read finishes successfully the decrementer gets "cleared". But if the read doesn't complete the decrementer value reaches zero and throws an exception, a disk read error is assumed and the game halts.
If the CPU is overclocked the decrementer will count down faster than expected, for example on wii the bus runs at 60750 ticks/ms so it will only take 0.6667ms to count down from 40500. Games won't be aware of this so they will still assume the bus clock is 40500 ticks/ms and program it based on that value. This means the decrementer will count down faster than expected causing incorrect timeout errors.

So errors and crashes are guaranteed to happen with most games?
I think you wrote something like that earlier, I dunno, forgot. That would possibly make all games unplayable.
Project Idea scrapped. :(

[emu_kidid]

I haven't read this thread, but just buy a Wii if you want more CPU power.

[mautheus]

I haven't read this thread, but just buy a Wii if you want more CPU power.

I fully agree. So you have less work.

[noobcube]

Although replacing/overclocking the GC CPU appears not to be an option, there are some real world advantages to running certain GC games at Wii clock speeds. Under Devolution, some games which struggled on the GC are able to maintain higher frame rates and play noticeably more smoothly.

[novenary]

Which games are effected ?