Mark Sokolovsky Brings a Vintage 2006 iMac Up-to-Date with an "External" GPU, Display Upgrade
Replacing the original MXM graphics card with a PCIe alternative and the display with a modern high-res panel, this iMac lives again.
Apple enthusiast Mark Sokolovsky has penned a build log on his project to turn a nearly-two-decade-old iMac into something shiny and new, with a higher-resolution display driven by a discrete GPU.
"In late 2006, going right along their fall product cycle updates, Apple had introduced a 24" iMac model for the first time," Sokolovsky writes on the Low End Mac website. "It’s a wonderful Mac to use, when it works. The primary issue with the 2006 24" iMac is its GPU, which tends to fail. Most commonly, the NVIDIA GeForce 7300 GT is to blame. Not only this GPU is long in the tooth (not worth replacing), there are hardly any MXM 1.0 GPUs to replace it with, let alone ones which work."
Sokolovsky's solution was to ditch the entire idea of having the graphics processor on the machine's motherboard — even on a theoretically-replaceable module — and instead borrow a trick from high-end gaming laptops: a connection to an external GPU, or eGPU. Specifically, Sokolovsky connected the vintage machine to a AMD Radeon HD 2600 XT 256MB, an admittedly vintage piece of hardware itself but an upgrade on the original GeForce it replaces.
Rather than having this GPU sat in a box truly external to the iMac, Sokolovsky came up with a solution to put the card in the original machine's housing by connecting it through a mini-PCI Express to PCI Express adapter in place of the machine's stock AirPort Wi-Fi card. The only caveat: the PCIe adapter itself is attached to the rear of the iMac, with a ribbon cable running back inside to connect to the Radeon HD GPU.
At the same time, Sokolovsky carried out two other upgrades — adding a solid-state drive (SSD) and a memory upgrade — and replaced the original 24" display with something newer and higher-resolution. "Basically, a regular ol’ Asus monitor was torn apart and stuck into the iMac," Sokolovsky explains. "The original iMac internal LCD frame was superglued on and taped on carefully, providing a durable hold which can still be easily disassembled if needed. No screw holes line up with this modern panel, unfortunately."
Sokolovsky's full write-up, which includes details on upgrading the machine to a supposedly-incompatible macOS X Yosemite operating system, is available on Low End Mac.