Help Upgrading Power Mac G4

Discussion in 'PowerPC Macs' started by Gelsomino, Dec 29, 2013.

  1. Gelsomino, Dec 29, 2013
    Last edited: Jan 3, 2014

    Gelsomino macrumors newbie

    Dec 29, 2013
    Hi all, a while ago I got a G4 and thought about upgrading it but didn't really have the time, now I do.

    *I want to upgrade this one, NOT buy a more modern, used tower*

    I will try to give you guys as much info as possible:

    I'm very much a beginner when it comes to modifying PC's/Macs but have some basic knowledge.

    I know there are tons of threads about this kind of thing but my eyes hurt from looking at the screen, I've spent days trying to research this but what one source says will/won't work, another 3 say the opposite!

    I am 99% I have the AGP version, 400MHz, 64MB SDRAM, 10GB HD, all stock.


    When I first got it, it booted up, now it doesn't, a mixture of 20 year old dust and crap just took its toll I think, I'm pretty sure it's the PSU thats blown, so I'm in the process of checking the voltage as per the G4 service manual, to determine this and will update as and when.

    These are the upgrades I want to make (with appx. specs and prices):

    1) HDD - anything over 250GB (£40ish)
    2) RAM - MAX 1.5GHz/2GHz (£30ish)
    3) PSU - 500W (£20ish)
    4) Processor - No idea on which one (£20ish)
    5) Graphics - I've heard about Raedon 9800 and GF 7600? I've also heard about GF 6200?!?! Too many! (£20ish)
    6) I will add an Airport card for wi-fi also. (£15ish)


    I think thats pretty much it, I will edit if I've missed anything, but what I need help with is determining what hardware to use for the job, and any modifications, or things that I should know that will make this impossible.

    I don't want to spend loads on this, I have resources but I want to do this for as little as possible.

    Any help/advice would be much appreciated :)

  2. eyoungren macrumors Core


    Aug 31, 2011
    ten-zero-eleven-zero-zero by zero-two
    If you mean hard drive (ram and memory are the same thing), 320GB is the largest you can get. That would be Western Digital Scorpio Blue series. They also made a 250GB drive. If you can find one, I'd go with that. I say made, because IDE drives are no longer being manufactured so anything you buy is out of the remaining stock that was made and the manufacturers are trying to get rid of. Or, there are refurb drives.

    An alternative is to get a PCI Sata card. Sonnet makes a few cards and having one allows you to install SATA drives which have higher capacities. One of these cards combined with the internal drive system can give you four drives. But the cards are expensive and most sellers on eBay seem to realize that so you can't really find a deal there. About $80 for the card or so.
    The AGP 400/450s will support 2GB max.
    eBay maybe?
    Sonett and some others made (they do not make anymore) CPU upgrades for the G3s and G4s. My own Quicksilver has a 1.2 Sonnet upgrade. You can find similar on eBay. Sonett did make dual processor upgrades.
    I've been told that the ATI 9700 Radeon is a good card. Hard to find though and certainly not for the price you're looking at.
    I don't believe the AGPs supported the Airport card, but I may be wrong. BTW, if they do it would be the original Airport card and not an Airport Extreme card.

    I have the 450 AGP at work so I know a few things to help with.
  3. ifrit05 macrumors regular


    Dec 23, 2013
    Near Detroit, MI. USA
    PSU: If you can't find a decent priced one online, you can always convert a PC PSU to work in a AGP G4. ("AGP" G4's [Sawtooth] have a 20 bin PSU power connector and DO NOT have a ADC above the AGP port.)

    CPU: Just look on ebay and try to find at least the 533MHz OEM G4 CPU card (it should look like a little square board, ones that are different shapes wont work). Dual CPU's might work also. It should look like this:

    And yeah the original AGP G4's do support the AirPort, the original not the Express/Extreme. It Looks like a PCMCIA card.
  4. Intell macrumors P6


    Jan 24, 2010
    I don't think the ATI Radeon 9700 works in non-MDD G4s. One good cheap yet powerful card to consider is the GeForce 6200. Just note, they are not a good card for gaming with.
  5. KeegM480 macrumors 6502a


    Aug 13, 2013
    Orlando, FL
    I dont really have much advise for you.

    I do have to say its really cool that you would rather upgrade an old computer than by a new one. Its great practice and loads of fun! I did just a simple RAM upgrade on a PMG5 and have never had more fun! Good luck!
  6. harrymatic macrumors 6502

    Dec 30, 2013
    United Kingdom
    Upgrading these Power Mac G4 machines is a blast - I've been working on my own. Beware though, it's incredibly hard to stop!

    The easiest thing would be to mod an ATX power supply - see

    Graphics card
    It sounds like you have a Sawtooth G4, the very first machines with AGP. Unfortunately they only have AGP 2x, which would limit your choice of cards. I actually have a compatible GeForce3 Ti 200 64MB which I'd be happy to sell for £10 delivered if you want it. It was a PC card that was flashed to work in a Mac, so it has VGA and DVI outputs. You can't use them at the same time unfortunately. It also caused my G4 to crash when resuming from sleep mode, but I think this might just be my machine. It's actually quite a capable card considering its age - I was able to run some fairly demanding 3D games like Halo on mid-high settings with no slowdown.

    Don't bother with the onboard AirPort slot/card - it only supports 802.11b, which is slow and rubbish. Get one of these: They support 802.11g - much faster. The best thing is that Mac OS X thinks its a genuine AirPort Extreme card so you don't need any software or drivers to make it work.

    Hard drive
    I really recommend you get a PCI SATA card like eyoungren mentioned. They let you use modern, high capacity drives (even SSDs) and are faster than the on-board ATA controller on these boards. You don't have to spend much at all on these - I flashed a £10 PC one to work in a Mac, and I've recently posted a guide on how to do this :

    As soon as you get the power supply up and running again, I really recommend that you update the system firmware - see . Otherwise, you may have problems running OS X and general instability with all of the upgrades installed. This has to be done from OS 9, though I would imagine this is what's already installed on the hard drive.
  7. gavinstubbs09 macrumors 65816


    Feb 17, 2013
    NorCal boonies ~~~by Reno sorta
    Making a maxxed out mac of any desktop is fun! My Mac Pro is in the process of being upgraded and I have 12GB ram, a blu ray burner, 5750 card, SSD, all these little things and in the future 2x quad cores for even more performance. My next system I'll be working on (if I can get one) is a MDD. I always loved them and want to max one out!
  8. Cox Orange, Jan 1, 2014
    Last edited: Jan 4, 2014

    Cox Orange macrumors 68000

    Jan 1, 2010
    1) Memory - anything over 250GB (£40ish) i.e. Hard Disk Drive "HDD"
    - No a 320GB WD Scorpio is not the biggest, it is just the biggest 2,5" IDE ever produced. The G4 Towers use 3,5" IDE Drives and the biggest were 500GB (Hitachi, WD, Samsung, Seagate), you will eventually find a 400GB Samsung some times, the biggest is a 750GB Seagate IDE Drive (goes for 100,-EUR on Ebay, because it is very rare. You can also use a cheaper small SATA Drive (2,5" or 3,5") with a IDE-SATA adpater (Bridge).
    - keep in mind the on board ATA/66-controller is limited to 128GB. You can install a fimrware hack to use bigger Drives on that connector. (I think there were two hacks, you can find them at or search the forum or google)
    - the optical ATA-drive connector is limited to ATA/33 (16MB/s) and I would only use this for a OS 9 partition or as a place to dump files you rarely use.
    - If you want to use bigger Drives without installing the OpenFirmware hack, you can use a IDE-PCI or SATA-PCI card.
    Sonnet/Seritek/Firmtek/Acard 2x SATA cards are bootable, those with 4x SATA are not bootable. They are all a bit costier. If you want to go the cheap road, search for a "Windows"-SATA-PCI card with SIL3124 chip. You can find a Mac driver online.
    Beware, if you use a 32bit SATA card (gold Pins look like this you will have 30MB/s max throughput, if you use a 64bit PCI or PCI-X (not to be confused with PCIe / PCIexpress) you will get 62MB/s max. The Pins look like this
    - you can use the "PC" or "Windows"-cards with SIL3124 and SIL3112 Chip without flashing (just drivers needed), but they will not be bootable. If you come a cross a bootable card it has always to be flashed with the firmware of the Sonnet/Seritek/Firmtek 2xSATA card. For flashing see
    There is a card by Macally that supports boot and even reads SMART, but does not support a lot of drives.
    List of compatible SATA-PCI-cards:
    2) RAM - MAX 1.5GHz/2GHz (£30ish)
    - GHz is for Processors (Frequency), you mean 2GB.
    3) PSU - 500W (£20ish)
    - most PC ATX PSUs have a fan at the side and the rear. You will want to find one that only blows out at the rear side, if you do not want to cut the case or the internal metal shield. Somewhere in another thread I posted models that have only this rear fan. How to convert a ATX PSU for G4 see at or
    4) Processor - No idea on which one (£20ish)
    - cheapest upgrade is to get a stock CPU for the 100MHz FSB of the AGP-Model it is the 500GHz or 450GHz Dual or 500GHz Dual. I am not quiet sure, if the 133MHz-FSB CPUs (from DA-Models) are compatible, they have at max 733MHz or Dual 533MHz. The Quicksilver CPUs (up to Dual 1GHz) do not work without some electric modification.
    - There are expensive third party upgrades from Sonnet, PowerLogix, Newertech, Gigadesigns or MaxPower. There are different chips used: 7455b (same as in the later Quicksilver models), energy hungry but faster than a same GHz-numbered 7447. 7447 very energy saving, but the 1,8GHz is as fast as a 1,25GHz MDD stock CPU (7455), 7448 energy saving and faster or as fast than the 7455, the 7457 is the most desired, the best energy to power ratio. There are details like an additional L3 Cache which I will not run into now. There are benchmarks on barefeats and for comparision. Focus on those that count the elapsed time of tasks, not those that let a benchmark tool count FPS or MB/s.
    5) Graphics - I've heard about Raedon 9800 and GF 7600? I've also heard about GF 6200?!?! Too many! (£20ish)
    - in Macs the CPU does the most, so you can do a lot without upgrading the card. For gaming there is extra eye candy or stability you will achieve with better cards.
    PC-Cards, that are flashed for the Mac lack of Hardware acceleration (Open GL) under OS9, (a simple game like Cro-Mag-Rally will not be playable, other games will just baa, but let you play it.) You will have to resolder resistors to make HW accceleration work (see themacelite ATI 9000 flashing guide).
    There are some cards that have Core Image (you need that for effects in OS X or the translucent menu bar in OS X 10.5), but no Hardware acceleration under OS 9. The ATI 9000 is a cheap solution you can get by buying a defective Quicksilver or low end MDD (will cost the same as bought seperately), funnily the predecessor ATI 8500 was a BTO/CTO upgrade and is better in games than the 9000.
    Look here for additional info (the following pages cover OS X) and themacelite (with flashing tips).
    Themacelite lists some cards as uncompatible with 2xAGP, but the 9800 for example exists as a 4xAGP card (two cuts, vs one cut in the golden Pins), which should work and it is the easiest and fastest to flash (best for OS X, but for OS 9 you might want a real Mac card, that supports HW accelleration. A real Mac 9800 does not support HW acceleration under OS 9, too, because Apple and ATI never released a driver).
    6) I will add an Airport card for wi-fi also. (£15ish)
    - just by a USB donlge. If you want to get past the USB1 speed with the dongle, than use a PC-USB-PCI card with USB2 (no flashing or drivers needed, just look out for one with a NEC chip).

    An additional note about the PSU the most heat in these Macs is exausted through the PSU and the Watt consumption rises with heat. So you will want to be sure you have enough cooling from the rear fan in that PSU. (you can put an additional 120mm(!) fan at the front side of the PSU). If you do not have the first PCI-slot used, put out the cover and you can even use a 80mm fan in the space between the PCI port and the HDD. Though I find, it more adds noise than cooling. Some put an additonal 80mm fan where the Airport-card would sit.
  9. Gelsomino thread starter macrumors newbie

    Dec 29, 2013
    Thanks for all the help everyone! My replies might be a bit sporadic just because I have a few things to do at the moment, but I will be checking this as much as possible! I've just got a multimeter to confirm that the main problem is the PSU and, surprise surprise, it is.

    So the next thing on my list is to order a new ATX PSU, this might sound stupid, but for what I want to do, what would be the best power? I was thinking, the more powerful, the better, just to be safe, and also mainly because I've seen that higher watt PSU's can actually be cheaper than lower watt PSU's?

    If I get a 500W or higher PSU (I am assuming that is quite big for a PSU?), can it be dangerous? What if I don't need all that power?

    I'd rather not get a power supply that will just about cover my needs, if it is safe to get a power supply that is capable of handling everything and more, for the same price.

    Thanks again everyone, I really appreciate all the advice :D

  10. harrymatic macrumors 6502

    Dec 30, 2013
    United Kingdom
    It's perfectly safe to use a higher rated power supply than what you require, the circuitry will only draw as much current as it needs. By all means go for the higher wattage PSU, you may end up needing the extra juice down the line. :)
  11. Cox Orange macrumors 68000

    Jan 1, 2010
    The Gigabit Ethernet G4 has a 338W PSU and just about handles a CPU Upgrade plus ATI 9800 and several HDDs and additional PCI-cards, but save and stable would be more Watts.
    This might be interesting for you to determine the right power.
    and (some info is spread over the thread, so reading it through is good ;))

    A new PSU would be more heat-vs.-power efficient anyway and have a better PFC (as the stock PSU).

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