How to Fit Your PC in a Power Mac G5 Case

April 17, 2011 BuildIts Computers

Whether you are an apple fan or not, it is hard to disagree with the fact that the Power Mac G5 computer looks great, inside and out. My goals for this project were to preserve the look of the case, inside and out; fit my PC's hardware, including a full length ATX motherboard, 2 GPU's, and a CoolIt ECO; and keep the system fully upgradeable, meaning no modifying the hardware.

I started out with a broken Dual 1.8 Ghz G5 with all the parts save the HDD's.

Although it looks very neat and tidy on the inside, the G5 is an absolute pain to completely disassemble. Here are the CPU's mounted to their heatsinks. The stock AMD cooler is for size reference:

Here is the PSU compared to a standard ATX one:

Motherboard:

Interestingly, the motherboard has its chipset heatsinks on the back of the board, rather than on the front:

To start, I completely emptied out the case, including the latching mechanism that holds the side panel on:

Since this case must fit a full ATX length motherboard, I had to cut the top divider to give the board clearance:

Since the motherboard now sat where the HDD cage was mounted, I had to move the cage forwards so the board could fit under it. For it to fit, I had to cut the cage's plastic shorter:

Then I screwed it to the divider:

I then reinstalled the latching mechanism:

Since I wanted to keep the original internal look of the G5, I rewired all the stock fans to fit standard Molex connectors. All fans run of 5V, since they sound like leaf blowers at 12. I used wiring diagrams found HERE. For the front pair of fans, I reused the slide-in plug, so the fans can be hot-swapped.

I ended up not using the HDD bay fan and blower for clearance reasons, but I did wire them up as well:

To mount the motherboard, I removed the stock standoff by popping them out with pliers, and built a motherboard tray out of the steel side panel of an old case and some aluminum flat bar.

Because the stock G5 PSU is much longer and shorter than an ATX one, mounting the power supply was one of the most difficult parts of this project. Also, the front fans and the CPU cover both mount to the bottom divider, which is screwed directly into the stock power supply. To fit an ATX one but keep the bottom divider, I cut a hole in both the divider and the casing of the original power supply. I then added an aluminum bracket which the PSU can be screwed to on one side using a thumb screw. The other side of the power supply is fixed down with a neodymium magnet I glued to the bottom of the stock PSU. If you happen to have to glue a strong magnet, remember not to used JB Weld, as it has steel in it. The glue is attracted to the magnet, so it flows around the magnet and tries to coat the outside of the magnet evenly.

When the CPU cover and fans are in place, the PSU is nearly invisible:

The next step was to rewire the G5's front panel to fit standard ATX headers. The wiring diagrams for this can be found in the same place as the fan pinouts.

Next I made a new back panel for the case out of some thin aluminum sheet scavenged from an old baking sheet. As it was, the back panel fans interfered with the motherboard's I/O, so I had to move the fans off-center. All the rough cuts were done with my a rotary tool, and then filed.

I used used the original fan grill as well:

I cut out the original back panel, and mounted the new one with hex screws:

Since I had to move the fans, they stuck out of the case, so I had to cut their plastic mounting bracket shorter:

Then I cut the PCI divider so that the motherboard could fit under it, and made a mounting bracket for it out of aluminum:

The PCI divider supports 3 fans as well as the CPU cover:

I epoxied the motherboard tray in place:

Then I transplanted my PC's innards into the case:

I removed the ECO's stock fan, and bolted it to the pair of back panel fans using spacers. This has had absolutely no impact on CPU temps:

My second GPU just barely fits: the passive heatsink is actually touching the top divider.

PCI divider and fans installed:

With the CPU cover:

Comments from Blogger

Anonymous — August 08, 2011 at 01:21 PM

Really cool! I have a powermac G5 but have problems finding myself using that because of a more up-to-date PC. I have been looking around the Internet for a good casemod so I know it can be done well enough. This seems like it really is done well enough!

Anonymous — August 22, 2011 at 10:52 PM

Very Well done.

Anonymous — September 05, 2011 at 04:56 AM

This is near perfection, you have done an amazing job! Give yourself a pat on the back :) Thanks for taking the time to do it right and sharing with us.

Francis — September 07, 2011 at 01:03 PM

why didnt you use the original psu? is it not possible or its broken too... i'm currently doing the same project..

Ben Katz — September 07, 2011 at 02:41 PM

The original PSU does not have the standard ATX connections. It would probably be possible to rewire it if you really wanted to though. I did not do this, because the PSU in this particular G5 was dead. The other option would to be to take apart an ATX PSU and put all the guts in the G5 PSU's case. I could not do this, however, because my PSU uses a rear exhaust fan rather than a top one, so the internal components were too high to fit inside the G5's PSU casing.

Kuffs — September 18, 2011 at 03:51 PM

Thanks for posting your progress, you and I are doing our projects pretty much along the same lines. I found your link to the simplified pinouts for the fans to be exceptionally helpful. I now have both running at 7W and it has some very cold air moving in and out. I do however have an update for you if you should ever decide to change your PS design. I disassembled my ATX PSU and successfully fit it into the mac PSU housing using the mac cooling fan instead of the large ATX fan. Here is a link to images on Flickr if you care to see: http://www.flickr.com/photos/kuffsinnc/sets/72157627458735392/

Ben Katz — September 18, 2011 at 04:59 PM

Your build is looking great so far! I would have reassembled my ATX PSU inside the casing of the old G5 PSU if it had fit. Since mine uses a rear exhaust fan rather than a large 120mm fan blowing directly down onto the PSU, the heatsinks in the PSU extend too high to fit inside the G5 PSU's casing.

Kuffs — September 18, 2011 at 07:33 PM

I understand what you mean, I picked out a PSU with a top mounted fan for specifically that reason. Thanks for the Kudos!

Callum O;Grady — September 30, 2011 at 11:27 PM

great build, great writeup! how did you mount the standoffs for the motherboard? i was thinking of just epoxying them to the aluminium sheet or did you screw yours through? im sure just epoxying them would hold wouldn't it? also with the power cord running to the PSU how do you run in through the case? the stock plug on the G5 looks like it wouldn't let anything through it or can a PSU plug fit through and just connect up inside.

Ben Katz — September 30, 2011 at 11:30 PM

The standoffs are screwed through the steel sheet, into the aluminum supporting bars behind it. I have seen others just epoxy standoffs on, but I personally would not trust that little bit of glue with supporting all my hardware. As for the power cord, once you remove the G5's PSU, a cord fits through the hole just fine. I thought about getting a short extender, so the power cord could just plug into the outside like on a normal computer, but I have not gotten around to it yet.

Callum O;Grady — October 01, 2011 at 07:05 AM

Whats your opinion on nylon stand offs? Something like this & just 2part epoxy them to the case? I don't have any cards on the Mobo just RAM and CPU. http://www.ebay.com.au/itm/8-Nylon-Motherboard-Standoffs-PCB-Style-Flat-Standoff-/370416395617?pt=LH_DefaultDomain_0&hash=item563e89a561#ht_2529wt_934 Thats good about the PSU, I thought that might be the case with it after looking at the pictures

Ben Katz — October 01, 2011 at 01:32 PM

Those may work, since they have a large flat base, but I really do not know how well epoxy will bond to nylon. Another option would be to remove the G5's original aluminum standoffs, and then epoxy or JB Weld them in the correct placement for an ATX board. A number of people have successfully done that.

Callum O;Grady — October 05, 2011 at 06:44 AM

Interesting idea there mate, thanks for all your pointers. I'll see how I go with the standoffs Might just make a motherboard try like you have done I'm picking up my G5 case in a few days so we'll see how it all unfolds! hopefully half as good as yours looks :)

Den — December 03, 2011 at 02:13 PM

Hey great build! I was wondering if you can still close the plastic cover or if the graphic card gets in the way? Also is it still possible to use the first PCI slot or is it too close from the divider? Really great work, thanks for sharing!

Ben Katz — December 04, 2011 at 01:59 AM

I cannot get the clear plastic cover back on, because it hits the GPU's power cables. If you have a graphics card with the power header coming out of the back rather than the top, the cover would fit just fine. The first slot should be useable, but if I did use it I would probably put something in to insulate it against the metal, like a thin sheet of plastic.

Kevin — December 14, 2011 at 04:51 PM

If you don't mind me asking, how did you mount the PCI/fan tray? I saw the L bracket on the back of the case, but what did you use or do to hold up the side toward the front underneath the optical drive? Great work and congrats on the clean mod!

Ben Katz — December 14, 2011 at 08:37 PM

Under the optical drive, the divider is held up by the original screws and standoffs built into the case. I did not have to add anything.

Kevin — December 15, 2011 at 11:39 AM

Great to hear, thank you for the quick reply! I've only got one stand off on that side that lines up with the tray, so I wasn't sure if that one would be enough to hold it without it bending.

Ben Katz — December 15, 2011 at 08:46 PM

I forgot to mention, in addition to being supported by a standoff and screw, it is also held up by the PCI fan and front fans, which both clip into it.

Anonymous — December 16, 2011 at 12:17 PM

awesome job! probably the best g5 mod I've seen!!

Anonymous — December 29, 2011 at 05:59 AM

That is awesome, I wish I had the time and patience to follow this!

Cody — January 14, 2012 at 11:11 PM

Nice work! I'm in the middle of one myself. Do you happen to know the size of the screws that hold the upper divider to the left side of the case? I just went out and bought a T8 bit (since my T6 was too small and T10 too big) but it still isn't right.

Ben Katz — January 15, 2012 at 03:37 AM

I used a T8, this one specifically: http://www.acehardwareoutlet.com/ProductDetails.aspx?SKU=2167260 I'm pretty sure all the screws in the case are T8.

Cody — January 15, 2012 at 09:08 PM

Thanks for the quick response. I finally found a T9 bit at Ace and it worked. Now if I can just find a drill bit that's close enough to the size of the perforations I'll be all set.

Ken — January 18, 2012 at 09:10 PM

Hi, Thanks for the picture and instruction. I am about to start the very same project. Could you tell me how did you get the locking mechanism and the top divider panel out? Did you have to take out the hdd cage and hdd fan first? I Can't seem to get those out either. I don't want to break them if there is an easier way to get them out. Thanks

Ben Katz — January 18, 2012 at 10:49 PM

I followed the guide here: http://www.insanelymac.com/forum/index.php?showtopic=4525&st=60&p=156892&#entry156892

Ken — January 20, 2012 at 04:23 AM

Thanks a lot. Helped me a bunch. I keep coming back to your site for reference :) Very Very helpful

Anonymous — January 25, 2012 at 01:24 PM

must be the absolute best conversion of a Mac G5 chassis, is itself to make a G5 chassis to the PC, but have not quite figured out how to do, but now I see how I can do if I want.

jamesr19 — February 23, 2012 at 12:12 AM

Hi, I've just got my G5 hack running. The only thing I haven't done yet is the front panel and was looking for your advice. If I just plug the power button socket on my mATX board into pin 13 it doesn't power up. It's like this with two front panels. I've read somewhere that the firewire needs to be hooked up for this all to work. Did you use firewire on your motherboard? how did you bypass it? etc? I'm basically wondering if you could just give me a quick guide on the front panel connector cable. My twitter is @j_d_robinson if that makes it easier to inform me. Cheers

Ben Katz — February 23, 2012 at 12:29 AM

To get the power button working you will need to have the ground for either the USB or Firewire connected to the motherboard. To make my front panel adapter, I just compared the G5's pinout to those of a standard ATX board, both of which can be found here http://img404.imageshack.us/img404/8747/powermacg5frontpanel.jpg and spliced the corresponding wires from an old case's front panel to those from the G5's front panel.

Dean — March 09, 2012 at 02:44 PM

Hi Ben, I wonder whether you wanna be paid to do a G5 case modding? I really wanna have one of this case, but I don't have those tools used here, and especially I am not talented as you're. So, if you are willing to help me, I will be thrilled.

Darren — March 10, 2012 at 06:05 PM

You've inspired me to do this for myself! I've got a dead G5 just wasting space and so when I'm building my new pc in around June instead of buying a case I'll just use what I already have! I'll be able to spend the 200 euro saving on fitting the case out with noctua fans also which should mean coupled with the great airflow of this case it will run cool all the time.

Anonymous — April 11, 2012 at 02:53 PM

I honestly thought you were going to use that p2/p3 mobo at first. great build, but the metal backplate is a bit ugly. I plan on using a tray to avoid that.

jyuphotos — April 18, 2012 at 06:27 PM

I was wondering how the CPU case, "G5 logo", was mounted? By the way epic setup :D

Anonymous — May 18, 2012 at 04:30 AM

Hey Ben, how many hours total do you think you spend doing this project? I have an extra G5, its way cooler than any PC case, just don't worry about going down a rabbit hole.

Ben Katz — May 18, 2012 at 11:45 AM

I finished the project in 5 days over a holiday. I put in a pretty significant number of hours each of those days, but a lot of that time was spent figuring out how to do everything, not actually putting it together.

Kris Naydenov — May 27, 2012 at 06:17 PM

Can you send me the template you use for the backplate? Thanks !!

Tom — May 27, 2012 at 10:17 PM

Hi Ben, this is a really cool mod, I'm planning on doing a similar build. I was wondering, what are your temps like and also noise? Cheers.

Ben Katz — May 27, 2012 at 11:01 PM

My previous case was a Thermaltake Element T, and I get the same temperatures in the G5 - about the 9800 GTX hits about 70-72 degrees C at full load, and the X3 710 maxes out at 33-35. It isn't especially quiet, due to the number of fans, but the noise is on par with other similarly fan-equipped cases.

Anonymous — May 29, 2012 at 08:25 PM

Got the G5 case earlier today & almost finished stripping out. Build commences shortly... These G5's are built like tiger tanks! Thanx for the effort with the build info - definitely helps :-)

Mark — August 07, 2012 at 02:00 PM

This project is awesome... If I could provide you with the G5 case, how much would you charge to do the case modification/setup where I could then install all the other parts?

Ben Katz — August 07, 2012 at 02:19 PM

Thanks, but I have no intention of modding these for commission.

Mr.D. — August 11, 2012 at 10:13 PM

Thank You Ben for your thread. A friend gave me 2 fully functional G5s with one 23" Cinema Display. I'm hacking one and sold the other to 'pay' for my hack. I linked to your guide in my sales post for people looking to buy the case and mod it (hope you don't mind) because your guide is one of the most detailed and best illustrated. I am successfully using JB Weld as others have, and I chose it because it has iron content in it, and I thought that might be a good thing when mounting the motherboard - although there are about 1000 threads out there arguing if you need the MB grounded or not. So I split the difference and 'kinda' grounded it with the JB Weld. One thing I wanted to share is that if anyone is not interested in wiring up the front USB/1384a/Audio themselves, there is someone who makes the cables for 30 Euros (includes shipping with tracking). You can find him in the forums at www.insanelymac.com.

Ben Katz — August 11, 2012 at 10:20 PM

Thanks, and good luck with your mod! The motherboard is grounded no matter how you fasten it to the case, due to it's many connections to the power supply's ground. Also, JB weld is not conductive: http://jbweld.net/faq.php#faq009

Mr.D. — August 11, 2012 at 11:33 PM

Yeah - the grounds that run thru the 12v/5v/3.3v lines... hence the arguments online about needing or not needing the MB to be grounded to the case thru the mounts. The MSDS (on the same site as this informal FAQ) for J-B Weld resin says it's 10%-20% iron powder by weight, despite saying that its an insulator. That is the reason why I said 'kinda' when referring to grounded. If your interested in the mod, its at http://www.insanelymac.com/forum/index.php?showtopic=281703

Anonymous — January 08, 2013 at 01:11 PM

where can i find one of these cases for sale? i'm building a new computer from scratch, have all the parts picked out, except for the case, i'd like one of these...

Ben Katz — January 09, 2013 at 02:41 PM

Try ebay and craigslist.

Anonymous — March 03, 2013 at 09:55 PM

Amazing build ,you inspired me to go same with my G5 thank you for the sharing. Can you also share the elcetric scooter you build? Again thanks alot for amazing project sharing. Yuvka

Anonymous — March 08, 2013 at 11:21 AM

holy. shit. you are a god. a buddy of mine just offered me his old g5 imac case, and my hackintosh is going to have a whole new sexy case.

StrAngel — March 09, 2013 at 08:54 PM

I didn't find the wiring diagrams that you linked to. Can you please send me those on email? suuhlem@gmail.com

Anonymous — May 12, 2013 at 10:26 PM

where did you get the i/o shield bracket?

Ben Katz — May 15, 2013 at 02:44 PM

I cut it out of an old scrapped steel case.

Anonymous — June 23, 2013 at 07:05 PM

Great build....i am stumped on how to get the power button, usb and firewire wired up or connected to the motherboard, please help?

Ben Katz — June 23, 2013 at 07:48 PM

If you make an account at InsanelyMac you can download the file in the first post in this thread: http://www.insanelymac.com/forum/topic/109381-powermac-g5-diagrams/ It has all the wiring diagrams, including the one for the front panel.

Anonymous — June 23, 2013 at 08:03 PM

I have the diagram but my question is how to i go about doing it and what is needed and what do i have to have to make it work?

Ben Katz — June 23, 2013 at 08:11 PM

All you need to do is solder wires between the corresponding pins on G5's stock front panel connector and the standard front panel connectors from an ATX case. Some of the pins from the G5 and ATX connectors will not be used, if I remember correctly, but it still works.

Anonymous — June 23, 2013 at 08:14 PM

Do i have to remove the backplate where the power button is located?

Ben Katz — June 23, 2013 at 08:19 PM

No. I just spliced the wires directly to the front panel cable that came with the case.

Anonymous — October 22, 2013 at 09:11 AM

Hi Ben! A lot of planing and hard work, but you did just an awesome job. Inspired me to start shopping for an old G5 and do my new Hackintosh build in this case, instead of the old boring standard atx case that I was going to use. Fellow modders appreciate this kind of detail.

yeh — December 11, 2013 at 01:28 AM

Cool post apart from the main aspect. How do you take the parts out?? I have been in the case for an hour taken out every visible screw and the main board wnt budge the fucking thing is built like a tank and there is not a single guide online. Some one please help. Cant empty the case

apple desktop repair — December 24, 2013 at 09:22 AM

sonnjita — February 11, 2014 at 04:56 PM

This multimedia power board for your much needed and valuable electronic device varies depending on the power of the wave too, and will help to avoid problems sorted circuit.

kaiomatico — February 11, 2014 at 08:48 PM

Awesome mod! I'm looking forward to get my case within the next week and start this project :)

rayczar49 — February 16, 2014 at 07:22 PM

Hi there, I'm just now started on this build and it's going to take me about a 2 weeks to finish it. I have a concern with my PSU not having enough power for all the fans once it's running. I'm going to be using all but one fan (the Blower fan near the HDD). i'm also buying a fan controller that hooks in to system fan slot on the MoBo. that way it can keep it quiet at idling and leaf blower when its crunching. Should i upgrade from Corsair CX 430 to a 500 or 600 watt unit to provide enough power. here is the fan controller: http://amzn.com/B004LKZESI Hope to hear from someone or Ben. Thanks

Anonymous — February 26, 2014 at 02:49 PM

how much does this all cost, and will it make a suitable gaming computer?

Anonymous — April 25, 2014 at 03:09 PM

This is amazing! Thanks for the great documentation!

Anonymous — July 05, 2014 at 07:49 PM

Dang son! Thats a 200 dollar case! I could use that case, but just put a shelf in it and use it for my MBP, and hook up some connectors.

Anonymous — July 05, 2014 at 07:50 PM

The case is 200$, with the parts in it. You would have to remove all the parts.

Anonymous — July 24, 2014 at 10:14 PM

Beautiful Work, this coming from an avid Apple fan.

Unknown — July 31, 2014 at 11:09 AM

Fantastic work...well done,,and thanks for sharing.

Anonymous — August 10, 2014 at 10:26 PM

Is there somewhere to buy the PowerMac G5 Front I/O to ATX Cable or is there a better way that i can do it, please help?

Anonymous — August 10, 2014 at 10:28 PM

I forgot to leave my email....jinroh10@gmail.com

Den — October 02, 2014 at 02:08 PM

That's a great mod. Nice work.

Anonymous — April 30, 2015 at 01:13 AM

If someone has a copy of the PowerPC wiring diagrams.zip, can you upload it to mediafire and then link back to this blog? Neither links work.

Anonymous — August 17, 2015 at 10:04 AM

can i mount custom noctua fans?

Anonymous — December 15, 2015 at 02:57 AM

ditto

Anonymous — April 12, 2016 at 08:19 AM

Oooooooo I love this, You have done a great job!

Anonymous — April 17, 2016 at 11:49 PM

Thanks to your post, I was able to transfer my X58 system over and rocking it!

HeavenlyModz — April 24, 2016 at 06:28 PM

I just got a G5 case for $50 and pan to do this mod. I did not have a dremel but I have a drill and dremil attachment I think will work. I was trying to get the parts out last night and didnt have a torx bit that fit. I'll get it today. I got a filly working G5 2GHZ with 4gb of ram without hard drive for only $50. So I will be removing the parts and reselling them. hoping to get the money I put into this back. I am mounting a micro ATX board in this. I dont think I will have to cut the divider at the top this way. I will have to see. How did you cut the back to fit the I/O area to fit so good

Anonymous — May 07, 2016 at 12:25 PM

You're lucky I'm browsing this several year old forum as well lol. From the pictures it looks like he just cut out a large rectangle... I'm currently in the middle of my build as well.

Anonymous — May 07, 2016 at 12:26 PM

Anyone in progress of this build give me an email! Duston.foster12@gmail.com We can chat about build ideas. I like this tutorial, other than the way he cuts out the entire back

Anonymous — June 02, 2016 at 11:20 AM

Could you please send a link for the template or dimensions you use for the backplate? Thanks.

al — September 14, 2016 at 04:00 PM

I will love to do this with my old G5 . Thanks for the post. Any updates on new mods for the g5 to pc conversion??

al — September 14, 2016 at 04:00 PM

I will love to do this with my old G5 . Thanks for the post. Any updates on new mods for the g5 to pc conversion??

Anonymous — January 03, 2021 at 02:47 PM

Excellent work on the case. Did anything put you off modding your psu into the stock g5 psu casing? How good is the cooling and noise? Thanks for sharing this.