I’m working on a set of custom sleeved cables for a fully modular PSU, and want to make sure I’m using the correct type of wire. I was planning on using 16 awg copper stranded wire, a fairly cheap one I bought off Amazon. I recently read some posts about PSU wires needing to be rated to 300 volts - going back and checking, the wire I bought is only rated for 60.
How much would a cheap wire impact my system performance? Does it really matter?
It does matter because the sheath of the wire is what dictates its current carrying capacity. Different materials have different ratings in voltage and heat. You size your wire for your load. Now given the information you provided, I have no idea if it will impact your setup or if it actually will matter in your given case. It probably doesnt but I cant say I would want my system setup with under rated cable. I would probably just buy whatever rating was on the factory wire or better.
Its not totally relevant but take a look at table 310.15 from the NEC.
This shows how a wires ampacity needs to be derated based on its jacket rating and ambient temps.
but wait theres more
This shows how the same gauge wire has different amp ratings based on jacket type.
Really you need to figure out what your realistic load is, then figure out what youre ok with amperage wise. NEC says size your stuff for 1.25x your load…but take that with a grain because the NEC is written for the kind of wiring in your house. It does serve to show that ratings do indeed serve a purpose.
Most powersupplies come with 18awg cables (1.02mm²), so your 16awg (1.29mm²) are allready off to a better start.
Voltage rating:
The capacitors in the power stage on GPUs and on the mainboard are all rated 16V. So any cable that has insulation rated higher than 16V should work. As a baseline, I would take twice the maximum expected voltage (32V) and 80°C (176°F), higher is better (to some degree).
Performance impact:
None. This is a case of either it works or it does not.
Good luck & Have fun with your project!
Singularity Computers guide on Custom Cables:
This is the wire I have: 16 awg wire (bought it from Amazon, but this site has better specs on it.) The only two things that give me second thoughts are a: it’s rated for 60V (although that’s still well over the 12V the PSU uses), and b: it says it’s good for “rough electrical” uses.
the concern for me is the temperature rating of the wire. I’d like to see something rated for 90°C-105°C but PVC is usually around 70°C. In all likelyhood you’re probably fine, just make sure you’ve got decent airflow.
I figured using 16 awg wire would help decrease resistance and maybe help (or at least not hurt) with overclocking. I’m building in a really small case, a Cooler Master Elite 130. My PSU cables are only between 8 and 12 inches long, so that should cut down on resistance and EM interference. I guess I’ll just wire it up with this and see how it does.
This is my son’s PC, and I don’t want to give him crappy performance just because I cheaped out on wire 
.
In my whole history of tinkering with electronics, I only two times overloaded cables/wires.
One time was when I wired up a diode the wrong way, the other time was a miscalculation (0.2A vs 2A).
When the insulation is not directly touching mosfets, the CPU heatspreader or GPU core, it will be fine.
It says it’s rated to 185 degrees F, which is about 85 C, so that’s not bad. And all of the cables are routed carefully with pretty decent airflow.
I think youll be alright then.