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Comment by organsnyder | Hacker News Reader

That sounds like a better use-case for an eGPU.

Especially because the GPD G1, a new eGPU with an integrated GaN charger is using practically the same GPU as the Framework 16. The latter uses a 7700S while the GPD G1 is using a 7600M XT and as notebookcheck put it "The 7700S is the power efficient version of the RX 7600M XT with slightly reduced clock speeds (-100 MHz) and TDP (-20W max)" but the GPD G1 also has multiple VBios versions for different TDP targets.

I am using it to change from the ThinkPad X1 Extreme Gen 4 to a ThinkPad X1 Nano. The X1E4 is 2kg, I have a third party GaN + SiC charger which is just 330g. The X1 Nano Gen 2 is 970g, the GPD G1 is 920g so the two together is less than the old laptop alone, with a hopefully similar CPU performance and vastly higher GPU performance. And it's much easier to pack, the X1E4 has a hard time fitting in a personal item backpack. Only disadvantage is I can't really game from battery but oh well that was never a goal.

Similarly going with the Framework 13 could be an interesting solution.

The module on the framework basically is an e-gpu except directly on PCIE instead of thunderbolt. Why they couldn't make it quick swappable I don't know.

Hotswappable PCIE is really hard to do right, especially if you are using a non-standard connector. You have to guarantee that pins connect and disconnect in the right order or you risk damaging equipment.

And on top of that, while a connector might be perfectly safe with cold swap (i.e. power off), you can damage the connector if the circuit is completed and power starts flowing but you only have partial contact.

So it was probably preferable to just release a coldswap versions and try dabbling with a hotswap capable chassis in the future.

it seems like the right approach would be to have a switch that disconnects the wires while the GPU is being connected to ensure everything is connected physically before anything is connected electricly.

It's two 74 pin connectors that's way too many to physically switch. Also signal integrity through that many switches sounds like an absolute nightmare.

Connecting the ground first has been solved in many ways. Are there other significant issues here for pin order?

Speaking from experience, there is a big performance difference connecting your eGPU over PCIE and connecting over Thunderbolt. Usually people just take the performance hit with Thunderbolt because of convenience and they are usually using overpowered desktop GPUs but there are eGPU PCIE connectors for people who want the most performance.

Because this is already using a mobile chip with lower performance, Framework probably didn't want to tank performance any more by going with the lower bandwidth Thunderbolt option.

The performance hit is because Thunderbolt has at most PCIe x4 bandwidth, while internal GPUs are connected to PCIe x16 lanes. That's a massive loss of bandwidth.

But it also tells you a lot about why Framework didn't make x16 bus hot swappable, it's a significantly bigger engineering challenge.

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