The MXM card with the 3dfx chip in the center, black silkscreen, mounted on the MXM to PCIe adapter, green silkscreen

An MXM Take On The 3dfx Voodoo

[sdz] of Vogons forum brings us an unexpected device for the 21st century – a 3dfx Voodoo 4 card in MXM format, equipped with 64MB of RAM. This isn’t just a showpiece – this card actually, properly works when installed into our hacker’s Dell Precision M4800, and [sdz] tells us more on how the card came to be.

Structure diagram of the cardEquipped with a VSA-100 GPU, this card has a whole lot of support components for adapting old interfaces to modern ones. There’s a PCIe-PCI bridge IC, an FPGA, HDMI muxes, and a Realtek scaler for video conversion. Handling all the MXM interfaces would’ve been downright impossible, so the card also holds an LVDS header for the M4800’s panel. Plus, for testing all of it, [sdz] has developed a PCIe to MXM adapter board with minimal circuitry needed to have the card work – this is a seriously involved hack and it’s executed remarkably well.

The forum post shows a whole lot of the journey, from receiving the PCBs to code and FPGA gateware bringup, as well as videos of VGA and HDMI operation. In the end, our hacker shows us a fully working setup, the 3dfx card inserted into M4800 and driving its display, as well as overclocking experiments; the author has promised to open-source the card files in due time, too. It’s seriously nice to see DIY MXM cards in the wild, and if you ever wanted to build one, we’ve got an article tells you everything you could want to know about the MXM standard.

We thank [Misel] for sharing this with us!

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A standard-compliant MXM card installed into a laptop, without heatsink

MXM: Powerful, Misused, Hackable

Today, we’ll look into yet another standard in the embedded space: MXM. It stands for “Mobile PCI Express Module”, and is basically intended as a GPU interface for laptops with PCIe, but there’s way more to it – it can work for any high-power high-throughput PCIe device, with a fair few DisplayPort links if you need them!

You will see MXM sockets in older generations of laptops, barebones desktop PCs, servers, and even automotive computers – certain generations of Tesla cars used to ship with MXM-socketed Nvidia GPUs! Given that GPUs are in vogue today, it pays to know how you can get one in low-profile form-factor and avoid putting a giant desktop GPU inside your device.

I only had a passing knowledge of the MXM standard until a bit ago, but my friend, [WifiCable], has been playing with it for a fair bit now. On a long Discord call, she guided me through all the cool things we should know about the MXM standard, its history, compatibility woes, and hackability potential. I’ve summed all of it up into this article – let’s take a look!

This article has been written based on info that [WifiCable] has given me, and, it’s also certainly not the last one where I interview a hacker and condense their knowledge into a writeup. If you are interested, let’s chat!

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