When the pandemic hit and gaming with friends became my new social life, I needed a proper gaming PC. But let's be honest - most gaming rigs are ugly. So I found the ultimate solution: using an old Macintosh enclosure.
A legendary machine
Back at WWDC 2003, Steve Jobs walked on stage and unveiled what Apple called "the world's fastest personal computer": the Power Mac G5. At its heart was the PowerPC G5 processor, developed jointly by Apple and IBM, which Apple marketed as the world's first 64-bit desktop computer. It was a bold claim, and one Jobs leaned into hard, famously declaring that the 64-bit era of personal computing had arrived.
The machine was just as remarkable on the outside as it was on the inside. It was the first desktop computer from Apple to use an anodized aluminum alloy enclosure, a radical departure from the translucent plastics that had defined the iMac and Power Mac G4 era. Perforated on the front and back to maximize airflow, the design earned it a nickname that stuck for decades: the "cheese grater." Even the interior, largely invisible to most users, was reportedly shaped by Jony Ive's team with the same obsessive attention to aesthetics as the exterior.
With its clean lines and near-perfect ventilation, it's a masterpiece of industrial design that still turns heads more than 20 years later.
I've always been a fan of this machine.
I remember browsing Apple's website back when it was still current, marveling at it as the ultimate Macintosh. It was the most powerful machine Apple made, the one professionals doing serious, demanding work reached for. Even as a kid with no real use for that kind of power, I knew one thing: someday, I wanted this machine under my desk.
Finding a case
The first challenge in a project like this isn't finding the parts, it's finding the right shell to put them in. And for a Power Mac G5, that means tracking down a chassis that's over two decades old, ideally in good cosmetic shape, and ideally cheap, since the whole point is to gut it anyway.
I got lucky. I found mine online for close to 30 €, next to nothing for what it was. The case was in excellent condition, but the machine itself was completely non-functional. That didn't matter to me in the slightest. I wasn't buying a working computer, I was buying an aluminum enclosure with two decades of engineering behind it.
Once I got it home, I started gutting the machine, removing every original component: motherboard, power supply, drive sleds, fans, all of it. To make sure I didn't damage the chassis in the process, I followed this teardown guide, which walks through the disassembly step by step.
I made a point of keeping all the architectural elements: the internal frame, the drive bays, the plastic baffles that direct airflow through the case. My goal wasn't just to reuse the shell, it was to build a modern machine whose internals stayed as faithful as possible to the original G5 layout.
That meant preserving the original cooling zones Apple had engineered into the case, even though a modern system produces far less heat than a dual-processor G5 ever did.
Squeezing a PC Into a G5
Fitting standard PC parts into Apple's unique layout is no small task. The G5 was custom-designed down to the last millimeter, and neither the motherboard mounting points nor the power supply are anywhere close to standard PC dimensions. Thankfully, a small but dedicated community has sprung up around G5 case mods, and two companies in particular make this kind of project possible.
The first is The Laser Hive, based in the UK, which designs parts specifically for custom G5 builds. I went with their ATX G5 Kit, which includes two main pieces: an internal backplate that lets a standard ATX motherboard mount correctly inside the G5's custom chassis, and a rear backplate that aligns the motherboard's I/O ports with the original rear cutout on the case.
Fitting it required cutting into the aluminum chassis slightly to make everything line up. Not an easy or particularly comfortable step, taking a Dremel to a piece of design history isn't something you do lightly, but the result was worth it. Once everything was in place, the fit was perfect.
The second is BlackCH Mods, which produces an adapter kit that lets you keep using the G5's original power button and front-panel ports (USB, audio, etc.) with a modern ATX motherboard, instead of relying on generic replacement switches.
Parts list
With the mounting problem solved, I picked hardware that would be capable, efficient, and, just as importantly, small enough to fit inside the case without a fight:
- Processor: AMD Ryzen 5 3600
- Graphics: GeForce GTX 1650 Super
- Motherboard: Gigabyte B550M DS3H
- Storage: NVMe M.2 SSD (250 Go)
- RAM: 8 GB DDR4
- Fans: Noctua NF-B9 (92 mm)
Before touching the case again, I mounted the processor onto the motherboard, seating it into the socket, applying thermal paste, and locking the retention arm in place. It's a small step, but a satisfying one: the first moment the build starts to feel like an actual computer rather than a pile of parts.
With the CPU, RAM, and GPU installed, I did a full test boot outside the case, on a flat surface, before committing to the install. Bench-testing the hardware first meant that if anything was faulty, dead on arrival, or simply misconfigured, I'd find out immediately, rather than after wrestling everything into the G5's tight enclosure.
Everything powered on and worked properly, a small relief. Only once I was confident the components worked did I move on to actually fitting them inside the G5's chassis.
With the brackets in place and every cable routed, the modern hardware finally found its home inside the aluminum shell.
Finished Build
And here it is: the finished machine.
From the outside, nothing has changed. Same brushed aluminum shell, same perforated grille, same silhouette that turned heads back in 2003. Anyone glancing at it would assume it's an untouched, if unusually well-preserved, Power Mac G5.
But under the hood, it's a completely different machine, the performance gap is quite impressive. The new CPU offers ten to twenty times the performance of the dual-processor G5 from 2003. As for graphics, they are up to 1,000 times more powerful, illustrating the technological gap between GPUs from the early 2000s and those from the late 2010s.
Good design is never really about the spec sheet, it exists outside of time, and two decades later, this case proves it's never truly outdated. What started as a dead machine in a stranger's garage now sits under my desk, doing exactly what I imagined it would when I first saw it on Apple's website all those years ago.
Links
- Power Mac G5 Brochure (2003) on blog.aventure-apple.com
- Guide to disassemble a 2005 Apple PowerMac G5 on Linus Tech Tips
- Apple Newsroom, "Apple Unleashes the World's Fastest Personal Computer—the Power Mac G5" (2003)
- Apple Newsroom, "Apple and IBM Introduce the PowerPC G5 Processor" (2003)
- Cult of Mac, "Today in Apple history: Power Mac G5 is 'world's fastest personal computer'"
- Pictures of the Power Mac G5 (Dual Core, 2.3 GHz, 2005) © Matt J. Fuller