Question Using a 24-pin ATX 90 degree angle adapter at the PSU end ?

[sacentre]

Can anyone confirm if it's OK to use any 90 degree ATX adapter at the PSU end instead of the motherboard end they are normally intended for? There's not a lot of space in my ITX case below the PSU sockets and an angle adapter would be a much neater solution for the ATX cable.

The particular Cooler Master one I want to use has anti-ripple caps built in so I'm wondering if it makes any difference which end of the 24-PIN cable it's used on. The cheaper no-brand ones are direct pin to pin connectors (with no caps) so I'm confident it makes no difference which end they go - like an extension cable.

I'm just worried their might be some difference with the Cooler Master one that I'm not aware of?

TIA

 

[Viking2121]

Its most likely on the motherboard side, the PSU side is going to be a different pinout or even a different plug or 2 plugs even, I haven't seen any right angled adapters for the PSU side of things.

 

[sacentre]

Thanks for the reply. I won't take the risk with the CM product. But just to be clear, if I use an adapter which is just straight through pin to pin connections - like an extension cable - and plug the normal cable supplied with the PSU into that, there shouldn't be any problem, right?

 

[Misgar]

or even a different plug or 2 plugs

As Viking says, it's possible your Cooler Master has two different sized connectors on the PSU chassis. The associated 24-way modular cable might be similar to the one shown in the photo below, with a 10-way and a 14-way connector at the PSU end and a 24-way (20+4) at the motherboard end.

If your Cooler Maater has modular connectors and the ATX 24-way feed comes out on two connectors, e.g. 10-way + 14-way, you won't be able to plug a standard 24-way right angle adapter directly into the PSU.

 

[sacentre]

Thanks for the detailed reply. The CM adapter I have is this one.

https://www.amazon.com/Cooler-Master-Degree-Adapter-Capacitor/dp/B07HZ6B6R1

I emailed CM to ask if this could be plugged into the 24-pin socket on the PSU instead of at the motherboard end but they don't recommend doing this. I assume they're referring to the ripple caps which are intended for smoothing voltage at the MB end. Whatever the reason, I decided not to risk it.

However, I also have a no-brand adapter without ripple caps (like the JSER product lower down on the web page). This one is simply a direct pin-to-pin, M to F connector and is electrically identical to an extension cable. So, my assumption is this can be plugged into the PSU with the regular PSU supplied ATX cable connecting to the MB.

 

[Misgar]

Are you certain your Cooler Master PSU requires additional ripple filtering capacitors in your external 24-way right angle adapter?

This review of a CM 850W PSU shows loads of capacitors on the connector board, implying good ripple suppression. As you can see in the photo below, there's no easy way to plug a 24-way adapter into the 10-way and 14-way ports on the PSU.
https://www.tomshardware.com/reviews/cooler-master-v850-gold-v2-power-supply-review

I'm having difficulty interpreting the Ripple Graphs in section 3 of this review, because both the X-axis and Y-axis are specified in Watts, but milliVolts of ripple are mentioned in the title. I much prefer to see the figures in a table, where you can see if the exceed the ATX spec.

 

[sacentre]

Hi Misgar. I'm not sure if your question was intended for me. I have no idea if the CM adapter "requires" additional ripple filtering. This would be a question for CM. All I can tell you is the CM product I have has ripple caps installed.

Again, all I'm trying to do is provide a 90 degree angle for the 24-pin ATX cable that came with the PSU because of limited space between the botton of the PSU and the wall of the casing I want to use. This would be neater than making too sharp a bend in the stock cable. As the no-brand adapter (not the CM one) I'm thinking of using is simply a direct pin-to-pin Male to Female adapter, it is electrically no different than using a straight extension cable.

 

[Misgar]

I'm not sure if your question was intended for me.

Yes it was. I spotted the ripple suppression capacitors in one of the two right angle adapters you mentioned and wondered if you were trying to reduce the ripple level of a PSU, that might already be well below the maximum permitted level in the ATX specs.

If all you are doing is trying to squeeze a PSU into a cramped space and you don't want to strain the cables with tight bends, it shouldn't matter where you install the adapter.

Just remember that every additional pair of pin/socket contacts in series with the power lines, adds a small amount (tens of milliOhms) of resistance in each wire. Provided the adapter is of good quality with tight contacts, this shouldn't matter.

I'm happier with the concept of a short stubby adapter, than a longer extension cable. As an electronics design engineer, I try to keep power cables to a sensible length, without the need for extension cables.

The extra 8in (20cm) in a 24-way ATX extension cable adds unwanted contact resistance. A better solution would be to buy a PSU with longer wires that reach the mobo. I've also seen new-fangled PSUs where the power leads exit on the side, instead of the end.
https://www.techspot.com/news/97251-corsair-creates-new-psu-side-mounted-power-connectors.html

I doubt your mATX? build is going to draw vast numbers of Amps through the 24-way lead, unlike an RTX 4090 pulling 450W via a dodgy multi 8-way PCIe to 12V-2x6 16-pin adapter, with the attendand fire risk.

I think your solution should be OK.

 

[sacentre]

Thank you for taking so much trouble over such a detailed and informative reply. I appreciate it. Especially the advice about adding resistance.

One reason I posted the original question is that I tried to check that the internal connections of the CM adapter were in fact equivalent to an extension lead (meaning that it wouldn't matter which end of the PSU cable it was attached to) but I couldn't establish that they were pin-for-pin equivalent. This may simply have simply been due to the presence of the ripple caps or some other reason so I didn't try it. The no brand one didn't have this issue. I might try the CM one now as this has just the right dimensions to fit my case perfectly (the output side exactly aligns with a small cutout in the casing).

Thanks again.

 

[Misgar]

I'd be very surprised if these right angle adapters weren't "straight through connection". It's highly unlikely any pins will be crossed over inside in a power connector of this type.

A simple check with a multimeter set to an Ohms range (continuity) should confirm one-to-one (pin-to-pin) connectivity.

The presence of capacitors from the supply pins down to 0V, shouldn't make any significant difference to the readings.