Re: Follow the specs :) (was Re: AMD GPU hard lockups)
On Thu, 3 Aug 2023 01:29:42 +0200
zithro <slack@rabbit.lu> wrote:
> On 02 Aug 2023 23:29, Celejar wrote:
> > But reputable companies do produce 6-8 pin adapters, e.g.:
> [...]
> > (I just ordered the Cable Matters one.)
>
> Out of curiosity, I checked the links.
> Funny that "reputable companies" (I'm not attacking you, but them) don't
> even specify the max power rating as product specs, and when specified,
> it's only in users Q&A ...
> You also have to dig deep to get the wires size in AWG (ie: zoom on
> pictures ...) !
> Compare that to the information you get for the PSU and the GPU !
>
> Anyways :
> 1st link: "The maximum power rating for the PCIEX68ADAP is 75W"
> 2nd link: "Max Power Rating 150W"
> 3rd link: (nowhere to be found, at least quickly)
>
> 1 and 2 use AWG18 wires, and on 3 they look even thinner (can't really
> tell as the pic is s***).
> I'd eliminate the 3 from the start. No specs, no money.
> And either 1 or 2 is lying : same AWG, different power rating (ok, the
> wire style is precised nowhere : single core, threaded, etc). But we can
> safely assume that 150W @12V is not possible : 12.5A is out of specs.
> (Try "https://www.engineeringtoolbox.com/wire-gauges-d_419.html"; for
> more info on AWG, and use the formula Watts = Volts x Amperes).
>
> On 02 Aug 2023 23:37, piorunz wrote:
> > Your GPU max TDP is 150W, meaning it will draw 75W from PCI-E slot and
> > 75W from 8-pin cable.
>
> So the wires will work around their limits.
> One little power spike and kaboom.
> Fire, exclamation mark ; fire, exclamation mark.
> Joke aside, the fire hazard is real. Especially exceeding limits with
> low-end products, when you don't know if the materials are fire-proofed.
>
> > Your 8-pin adapter must have been very poor quality. I don't know what
> > kind of adapter it was, but adapters which make 8-pin from 6-pin, are
> > dangerous. Better to use 2x 6-pin -> 1x 8-pin adapter to correctly
> > assign wires to each corresponding pin.
>
> I agree, so that each wire (or group of wires) does not exceed the max
> current it can draw.
>
> I found two pages cleanly explaining this, both were worth a read.
> But don't quickly jump to conclusions, follow the flow !
>
> https://www.cgdirector.com/gpu-power-cable-guide/
> https://www.pcworld.com/article/395059/one-cable-or-two-for-powering-a-graphics-card-heres-the-answer.html
Thanks for the information and explanations!
> zithro / Cyril
Celejar
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