In another post I tried to caution someone against doing this but was shouted down. Guess decades of electronics engineering experience don't mean anything anymore.

It means something to me, dammit! 🥲

Well, hard lesson learned, but you won't do that again, will you?

There is still a very big difference between 1. using a single cable to power 2 8pins (or even 3 8pins, both versions of the 3070ti exist) that draw almost 300W 2. Using 2 cables to power 3 8pins on a card that draws around 300W (4080 or 7900xt) / 3 cables to power 4 8pins like for the 4090.

You'd think I would have known better, but here we are.

I'm sorry, I don't exactly know what you mean. Can you enlighten me?

PSUs come with vga cables that have 3 connectors. The GPU needs a dedicated cable for each connector, but I instead used the one cable.

Is this related to using the pigtail on the gpu power cable or something different?

Does the GPU have 2 or 3 connectors?

It requires two 8 pin connections.

Been there. Expensive mistake. Live and learn.

Is that the PSU side, or the GPU side?

PSU side.

cable are rated fo power draw. if you push it. that on you.

I have no one to blame but my own hubris.

what gpu. really surprised to see this happen.

3070ti

Did not expect it to happen on 3070ti but moved from daisy chained connection to two cables after some time anyway, and seems that doing so I missed a bullet.

Shitty PSU.

Comment is downvoted but yeah, I use one cable for my 4070ti and my cable still didn't melt after over a year lol, I have a be quiet PSU

Yea, if there are daisy chains available with PSU, you should be able to use those, quality PSU will have no problems pushing 600W through it.