Quick update on this, seeing as actual progress on the machine is stalled (more on that at the end!) The GF4 looks like it's gonna be pretty awesome.

Remember my old QuakeSpasm score of 4.4 FPS? Well, how does 177 FPS sound for an improvement?? Not making that up:

GLQuake runs too now, and yields similar results:

^^ I have no idea why I couldn't get this to work with the Rage card as it's listed as supported in the official requirements... maybe some incompatibility with Leopard. But it works fine on the GF4.

You knew this was coming - how 'bout some UT2004?

^^ Incidentally this screen lies... it shows up on my Macbook with Intel graphics and even the G5 which has a Radeon. Derp de derp. However,

...the game runs great. Here it is at maxed out detail ("HOLY SHIT!") at 800x600. I forgot to actually measure the framerate because I was too busy blasting bots, but it's fully playable & doesn't seem to slow down.

Wipeout 2097 also plays well, although there's some issue with the shadow there that I didn't see on my G5 (it's not supposed to be grey, obviously.) Still, a really nice port. I like this better than the PSX version due to the higher resolution.

Unfortunately, I am getting a stability issue with the GF4 that I haven't been able to solve yet. I've noticed on cold boots it doesn't always seem to pick up the second CPU (System Profiler reports it as single & the CPU monitor only shows one bar.) Usually a reboot or two will fix this; the second CPU will show up & everything will be fine.

With the GF4 installed, in single CPU "mode" it's totally stable and you can play UT2004 or surf the web or do whatever else you want. However when the second CPU is showing up, it consistently hard freezes after 5-20 mins of use. This never seems to happen with the Rage.

My gut feeling is that the power supply is going (probably caps!) or the VRM on the motherboard is going bad? It seems like it can't supply enough juice to power both CPUs and run the big fans & the thirsty GF4 at the same time. I'm just wild-ass guessing here, but there are definitely some caps on the mobo that are gonna need attention. I've already had a bad PSU kill a G5; fortunately this one is TONS easier to get out if I need to open it up.

There are also some dodgy GSC caps on the GF4 itself. Story of my life...

Annoyingly this isn't one of the models that can be easily swapped to any old ATX PSU, the conversion would be a little more invovled. Totally doable though, or I could always open up the original and check it for caps. I would like to know if that's actually the problem before I put a bunch of work into it though.

Power supply is likely. A recap should help, but if the power supply is overloaded new caps will only have a limited effect. A new psu isn't outside the realm of possibility. A newer one, with more watts. It would let you put sata drives in without converters. I'd seriously look into it.

Why not add a GeForce 6800 ? 😀 and play some Doom 3 😁

The CPU Upgrade uses Custom/modded Firmware right ? i have a sonnet 1.4Ghz upgrade which refuses to work.
I think its because of the OBP.

I now got tiger up and running on my PowerMac G5, and it runs Postal 2.

^^ Yeah it does, I've actually got a boot CD with it that loads the firmware (which I should probably image and see if it's already online anywhere - bet those discs are hard to find.)

It looks like Sonnet still host most of their firmware downloads, hopefully you can find the right one there!

I have a nice BFG 6800GT OC but I couldn't use it because it doesn't have the AGP 3.3 key. Would've been boss though!

luckybob wrote:

Power supply is likely. A recap should help, but if the power supply is overloaded new caps will only have a limited effect. A new psu isn't outside the realm of possibility. A newer one, with more watts. It would let you put sata drives in without converters. I'd seriously look into it.

Apple machines from this time period unfortunately do suffer from bad capacitor quality. My eMac failed due to that; when I opened it up the caps were almost all burst... 😢

luckybob wrote:

Power supply is likely. A recap should help, but if the power supply is overloaded new caps will only have a limited effect.
A new psu isn't outside the realm of possibility. A newer one, with more watts. It would let you put sata drives in without converters.
I'd seriously look into it.

When I repaired my old G4, I thought about this. From what I can remember, one or two PSU wires were not conform to ATX standard.
Just saying. It's been years since the last time I read about this. In the end, I kept the old power supply, changed some caps and added a new fan.
That beeing said, I can't recommend this to anyone (safety reasons). Maybe someone sellls a working G4 PSU among other Mac parts on eBay or so.

^^ Mine is not quite the easy swap, but not one of the worst ones either. When I'm not buried under a steaming pile of work, I'm gonna rig up a second PSU just to run all the drives & fans and see if that improves stability. Then will see about repairing the stock one or building the adapter.

Stock PSU is 338W BTW. Earlier ones were only 200W because Apple.

Is this pinout right? These are from ATXG4.com, but I haven't been able to find an ATX pinout elsewhere that matches this one exactly.

Note that it's reversed from the way most other schematics show it (pin 1 is at the bottom) but even accounting for that I keep seeing inconsistencies.

Try running the GPU off a separate PSU, and improving cooling before going down the caps/ATX conversion route. Downlock your backside cache as well, using a utility such as Powerlogix' CPU Director

Thanks for Firmware Links, i will check it in time 😀