so im building a g4 tower for my friend...

The Sawtooth is also compatible w/ normal ATX power supplies, but has a slightly different pinout. More on this at XLR8. The DA requires a special power supply capable of delivering 28V. But if you do not bother the noise generation of the original Apple PSU, you can get one on eBay for few money.

do you think i would notice a big difference between a 2x AGP slot and a 4x, can i still use most video cards?

thanks!
eric

Some graphics cards like the Radeon 9600, are incompatible with AGP2x. But the fastest officially available graphics card is the Radeon 9800 Pro, which works fine in AGP2x mode. The performance should not be much slower than ran in AGP4x.

I recently built a G4. One thing I can tell you is that unless you get a really good deal on the parts it is hard to save any money by doing it. After watching out on eBay for a while I was able to a GigE logic board with PSU and CPU, and 512 MB ram and DVD-ROM for $90 shipped. During that time I saw logic boards alone go for $150 -250 with $200 being the average. You can often find G4 systems in the $300 to $400 range. So by the time you factor in the cost of a PSU and Case and other stuff you don't save much money.

All of the GigE and up logic boards require +28V to boot. Even without an ADC compatible video card. If you search the older post someone around here designed a circuit to kick the +5V standby on an ATX PSU up to +28V. Also be aware that GigE logicboard have a chip on the back that require a heat sink. I used a North Bridge heat-sink from a PC motherboard and ground it down to .210"

As for the video card take a look at stangedogs.com and cubeowner.com. You can get a 9800 to work in a G4 but it does require some modifications to the card. Due to Apple's use of reserved pins on the AGP slot.

I just bought a Quicksilver case for my project.. I am not sure what motherboard to put inside it, or how hard it woudl be to do so.. My main goal is to do a dual proc setup, and I woudl like to use a Digital Audio motherboard or Quicksilver motherboard..

I am not expecting to save much money, but more to learn apple systems better, and give me a project to work on.

Anybody know if a Digital Audio Motherboard will work in a Quicksilver case? I know the power supplies are unique between the two, and I have to purchase a PS still at this point.

Thanks for your help.

MW

Eric - be forewarned that although you can use a standard ATX PSU (with minor modifications) with the Sawtooth mb's - not all of the Sawtooth boards are capable of using DUAL CPU's. My suggestion is a Digital Audio G4 (they are 466mhz, 533mhz, dual 533, 667, and 733). I just bought one on ebay for $389 to replace my Sawtooth agp (which DOESN'T support a dual cpu card). The Digital Audio Mac has a noticable boost in memory speed and PCI Bandwidth. If you are looking for performance, I'd stop worrying about the PSU and start with a Digital audio G4 or higher. All the DA g4's have a 338watt PSU that is more than enough for the above average system. The 28v is required to get it to boot. Have you checked on prices for dual CPU upgrades? This is where you will be spending the most cash.

Correct, UNI-N7 is required to use dual processors. The Gigabit G4 was the first to fully support dual procs. Although later sawtooths had UNI-N7 as well.

EDIT: oh yeah, a gigabit G4 also requires the 28VDC supply to boot. You can easily tell a Gigabit from a Sawtooth by the big heatsink on the ethernet chip.