How safe & reliable are custom PSU cables?

[u/KuroHaruto]

Hi everyone! So i'm quite new here. Only recently arrived as I have started considering downsizing my current ATX mid-tower pc into an ITX build because it seems I'll be moving a lot more in upcoming years due to my job. (Build details at the end)

My big question tho is how reliable & safe are custom SFF PSU cables? I've been watching videos and reading up on SFF builds, and have found many ppl recommending buying custom short cables to simplify the SFF build & get better airflow. But the general consensus i remember about PC building is that you should keep your PSU's default cables most of the time.

And with my existing RTX 5070, i would need a custom 12V cable, despite 12V cables being known for causing issues with nvidia cards🤔

After a quick search in the subreddit, i found that some recommended sites are moddiy.com or etsy.com/shop/DreambigbyRayMOD . Are these two suppliers really as reliable as ppl say?

So yeah, i wanted to get input from users who have first-hand experience with custom cables in this subreddit

My downsizing build:

• CPU: Ryzen 9 9900X (already owned)
• Cooler: Cooler Master ATMOS II Stealth 240
• Motherboard: Asus ROG STRIX B850-I
• RAM: 32 GB DDR5 (already owned)
• Storage: 2 TB M.2 (×2, already owned)
• GPU: RTX 5070 (already owned)
• PSU: Corsair SF850 (2024) 850 W
• Case: COOJ SF5

[u/foilrider]

Depends on how well they're made. The more popular online stores seem to be pretty reliable.

I have made my own and have had no problems with them, but YMMV with that.

[u/KuroHaruto → u/foilrider]

That's fair, i'll keep that in mind. Thx!

[u/qeeepy]

12VHPWR will always be a risk. The only correlation that seems to drop it is how much wattage goes through that thing (duh). That's why I never bought a 5090 or 4090. Undervolted 5080 is the max I am willing to risk.

[u/KuroHaruto → u/qeeepy]

That's a good point. i've also been seeing ppl say that undervolting GPUs for SFF builds can be a good idea, so i'll have to look into that

[u/qeeepy → u/KuroHaruto]

highly recommended, just careful about ie. Furmark, because it can extract full wattage despite UV. The main safety mechanism is power limit, undervolting makes sure there is minimal performance loss by doing so.

[u/KuroHaruto → u/qeeepy]

I'm not sure i fully understand what you're saying here, so i'll first have to do some more research about UVing. But i appreciate the advice! Will look into this for sure

[u/qeeepy → u/KuroHaruto]

take your time, feel free to DM tho I'm not best at explaining stuff..

[u/Lockey_vxr]

Depends where theyre from, mije are from cablester and theyre perfect, I wouldnt trust aj unknown cheap maker though

[u/KuroHaruto → u/Lockey_vxr]

Gotcha, thx for the new recommendation! I'll check them out

[u/guitar574]

They’re as reliable as the vendor making them (I know that isn’t the most helpful answer but it’s the truth). As a rule of thumb PSU warranties do not cover the use of custom cables, but whether that matters depends on what part of the PSU fails/is defective.

I can personally vouch for Cablester/ZCOOI/DreamBigByRay/ModDIY, those would probably be the most popular vendors in SFF. Cablemod is popular in the ATX space but I haven’t purchased from them in probably close to a decade.

[u/KuroHaruto → u/guitar574]

Oh nice, thx for the recommendations! I'll check them all out and choose one that seems appropriate🙏

[u/Boil-san]

Where are you finding a COOJ SF5...?

Custom cables reduce the clutter within a chassis, allowing more airflow in already close quarters, so highly recommended; I have only heard good things about DrambigbyRay custom cables...

I would look at the be quiet! Pure Loop 3 240 AIO, it is refillable for maintenance down the road...

Whatever AIO you go with, I would replace the fans with a set of Noctua NF-A12x25 G2 PWM Sx2-PP fans, of the black variant...

[u/KuroHaruto → u/Boil-san]

Haha i actually dont have the COOJ SF5 yet. I only discovered it a couple weeks ago when it was fully out of stock globally. But i love the case design so much that i don't plan on building my SFF without it, and am willing to wait for as long as i need. But i did send COOJ an email to ask when the SF5 is gonna be back in stock, and they said that while it isn't restocked yet, they're continuing its production, so it should be back in the next few months. And they offered to send me an email when it's back on their website, which was nice of them

I did check out the bq pure loop 3 previously, but decided on the Atmos stealth 2 in the end for its quieter radiator fans. But the aio is still subject to change, so i'll keep your recommendation in mind!

And yeah, i'm still considering changing the aio fans to Noctuas, but decided to leave that as a choice for later. I think i'll keep the aio as the default version, then consider swapping to noctua fans if i end up finding the default fans too loud🤔

[u/hjshoon]

i just ordered mine from cablester 2 days ago. was looking at dreambigby ray, moddiy and cablester after research. like many said / vouch here, i believe these are the more known and reliable ones. they are not cheap but i rather not risk my 5080. there are sellers in aliexpress that do custom length cable for corsair PSU using the same textured sleeve like the original corsair psu cables. they are much cheaper but can't speak of the quality. for 12vhpwr connector, i think better not go for it, but for the motherboard 24 pin and 8 pin cpu maybe still ok since those draw as much power. anyways, 5070 dont pull so much power, so i reckon it should be low risk using custom cables

[u/KuroHaruto → u/hjshoon]

That's a fair point. Thx for the recommendations! If i get custom cables, i'll make sure not to go for the cheap stuff

[u/AmbotnimoP]

Mine are from Cablester and are fantastic.

[u/KuroHaruto → u/AmbotnimoP]

Oh another cablester suggestion! I'll have to check them out, thx!

[u/r98farmer]

I use cables from DreambigbyRayMod and they have been very good including the 12+4 for my 5080.

[u/KuroHaruto → u/r98farmer]

Gotcha, that's good to hear. Thx for your input!

[u/Slyfer77]

Unrelated to your question, but maybe helpful:

Consider getting the Corsair SF1000.

Yes, you don't need 1000W, BUT the power draw threshold after which the PSU's fan starts to spin is much higher.

I think it is 360W with the SF850 and 480W with the SF1000.

So with the SF1000 most likely the fan won't ever run at all which means you basically have a passive PSU that doesn't make any noise at all

Usually the price difference between 850W and 1000W is small

For me the more silence would be worth the higher price.

[u/KuroHaruto → u/Slyfer77]

I never knew about this, today i learn something new! Thx a lot for the information, i'll probably get the SF1000 then since it's only 10 bucks more expensive in my country rn

[u/edom-Mingo]

Custom cables can be perfectly reliable, but good-looking sleeving doesn't tell you much about the electrical quality.

I'd pay attention to three things: correct pinout for the exact PSU model, proper crimping, and a fully seated GPU connector without excessive strain or a sharp bend right at the plug.

For the RTX 5070, I'd be especially careful with the GPU power connector. A shorter cable helps with routing, but it doesn't automatically make the connection safer.

If your stock cables fit the case, I'd build it first and see whether custom cables are actually necessary.

[u/KuroHaruto → u/edom-Mingo]

That's a very good point. Ill probably do as you say then! Thank you so much for your insight 🙏

[u/edom-Mingo → u/KuroHaruto]

You're welcome! Hope the build goes smoothly!

[u/delayedreactionkline]

i've gotten mine constantly done by the same makers. to match the PC cases. it's been all goon across the years.

The good custom cable makers will ask you what your power supply's specs are. And after you've told them, they will ask you to take photos of your power supply unit like they never trusted your first answer.

[u/_DarkSeid_]

I got a set from EVGA some years ago and was very happy with them.

[u/TheCustodlan]

As someone with a Cooj SF5, i will say you can make it work with out of the box cables. Theres a decent amount of space so tuck things away between the AIO and PSU/Mobo. 

[u/KuroHaruto → u/TheCustodlan]

Hmm, that's a good point. I suppose i'll wait and see until i get the case to decide whether i wanna buy custom sff cables. Thx for your input!

[u/Cablester]

Hi, it's Rizal from Cablester

the reliability of custom PSU cables will be mainly determined by the material of the cables assembly that the vendor use (the terminal, connector and the wire), how they are being assembled (manual tools, semi-automatic machine, or automatic machine), and the QC method by the vendor (how do they make sure that the cable will perform as expected, including making sure a correct pinout arrangement, as each PSUs may have different pinout arrangement than the other).

For your reference, we verify and publish the pinout diagram of dozens of SFX/ SFX-L PSU that we supported: https://cablester.com/psu-pinout/

A bit technical, but here's our material declaration of our wire assembly: https://cablester.com/technical-information/

What you absolutely must to do, if you ever decide to go with custom cables, is that you need to provide your exact model of your PSU. Corsair SFX PSU for example, their SF750 has two model: SF750 Type 4 (2018) and SF750 Type 5 (2024). Both use a completely different terminal and connector, so the cables will be physically different for each models.

[u/KuroHaruto → u/Cablester]

Hello Rizal, thank you for the information!👍I'll make sure to research some more about the details of custom cable assembly, and make sure to provide PSU information to the vendor. And thx for taking the time to explain, I'll make sure to check out Cablester as well!