Howdy fellow PPC users! Last year I did a whole bunch of upgrading on my Digital Audio G4, and though I had a lot of fun doing it, the time and expense yielded much lesser results than I had hoped for. My goal was to cut down rendering time in FCE4, and it worked, but only to a small degree. It wasn't worth what was put into it, so I won't go into great detail about all that was done, but one upgrade of note that was especially fun was with the GPU. I wanted something more powerful than what I had (GE Force FX5200 IIRC), but options were limited until I came across info about taping pins 3 and 11 for modding a G5 AGP GPU to work in a G4. I'd like to mention two guys who were a tremendous help to me with this upgrade: Christian at old-macs.com and Donald at atxg4.com. Christian helped me pick out a GPU that would work in my machine (the EVGA nVidia 7800 GS CO), and helped me with a LOT of other stuff like info for picking the right PSU to power the GPU. We emailed back and forth constantly for more than two weeks. He was extremely helpful (and patient), before, during and after my purchase. The man really went WELL above and beyond to help. If you're in the market for a GPU, I highly recommend him. Which brings me to Donald, who was kind enough to answer my plea for help when I realized (I was on a learning curve with all of this) that standard PC ATX power connectors and Apple's version of ATX were two different animals. At the time the info on his website said that he wasn't taking orders for his G4 ATX adapters at all, but when I contacted him through the website he replied and hooked me up with one! He was very easy to work with and expedited the shipment. Just FYI, he has since updated his info and is taking orders again (but note he's not using Paypal). So for anyone who needs to or is otherwise interested in changing out their PSU, he can help with that if your G4 model is one of the ones he's developed an adapter for. My adapter works great, by the way. Incidentally, for my PSU I chose the OCZ Fatal1ty 750-watt unit. It sits on top of the computer (too big to go inside). I went this route because the 7800 GS needed molex power on a dedicated +12V rail with a particular amperage rating (18A IIRC). As a side benefit, the PSU itself is modular. Some other notable upgrades I did at the time (yes, these were worth it too): I also bought an OWC SSD for my boot drive (installed in the Zip drive bay), and 3 sticks of OWC "high-performance" CL2 RAM to replace my CL3 RAM (in case anyone has ever wondered, that CL2 RAM does make a difference - not a significant difference mind you, but I noticed an immediate difference after booting up and everything was just zippier overall). I also overclocked my aftermarket processor upgrade, for which I mounted 3 extra fans on the heatsink to get more air on and underneath so that I could run steady at dual 1.8 gHz (instead of dual 1.6 which is how it was configured when I bought it back in '06). I switched it at one point to dual 2.0 gHz, but afterward About This Mac reported only dual 1.93 gHz, and it was unstable when playing movies - it would freeze every few minutes. So, I switched it back to dual 1.8. It runs great at 1.8 - rock solid actually. As an aside, one thing I tried to do (unsuccessfully) earlier this year was to replace my ATA optical drive with SATA optical drive hooked up via a PCI SATA card like my other drives. Alas, after much investigation, the only real possibility I found was the FirmTek SeriTek/1V4, which is advertised on FirmTek's website as having ATAPI device support. But, the most I could get out of it when I tried to use it with a SATA optical drive (this one and one other LG model) was that it responded to the eject key on my keyboard, one time. It did not respond that way again, nor did it mount a CD or DVD on the desktop. It seems that PCI SATA cards for Mac that fully support SATA ATAPI devices don't exist.