ASUS motherboards with adjustable VIO (inductor L41 and a diode + MOSFET nearby) regulators (+3.3-3.5-3.6V) don't use the +3.3V line from the power supply at all.
Absolutely not.
That is, not at all.

The specs I gave are the overall combined (which is typical) specs for the 5V and 3.3V. Not need to make a fuss out of it.

Look, it's great you know where the resistors and diodes and whatnot are located on the motherboard, but for me, I don't care about the electronics, I just want to get this working without spending any further. I can't use RM850x with this "hobby" computer because I need it for my main rig.

hydraphone wrote on 2025-12-17, 14:43:

The specs I gave are the overall combined (which is typical) specs for the 5V and 3.3V. Not need to make a fuss out of it.

Look, it's great you know where the resistors and diodes and whatnot are located on the motherboard, but for me, I don't care about the electronics, I just want to get this working without spending any further. I can't use RM850x with this "hobby" computer because I need it for my main rig.

I don't like giving ready-made solutions; I prefer users to think for themselves.
If you need ready-made solutions, you can turn to ChatGPT - ‘why doesn't the newer ATX standart PSU work if one of the power rails is completely unloaded’.
I have explained the initial conditions to you, now it's up to you.

Let me return your advice in kind: how about you take your ego-boost-seeking pointless comments to a local teenager electronics club and don't contribute to this thread, unless you have something that's actually useful? That way, we can have a construction discussion here and you can get the daily ego boost that you need by telling kids that you actually know where inductor #71 is located on a 30 year on motherboard. It's a win-win.

So the RM650x is using LLC + DCDC as it's topology, meaning the main voltage it generates is 12V and the 3.3V and 5V are generated from individual DC/DC converters, powered off of the 12V.

https://www.tomshardware.com/reviews/corsair- … psu,4611-3.html

So it should not really care if there is load on those rails or not to maintain a stable voltage. There is no cross-regulation issue in such a topology.

If you can, try to give the rails of the PSU a measurement for the 3.3V, 5V and 12V rails with a DMM, checking if there's anything "out of the ordinary"

Thanks, tehsiggi, that's useful. I doubt there are such issues with the RM650x, since I was using it until yesterday on my main rig. I also just tested with Luck Star 6ALX with a Mendocino Celeron and it's working fine with it.
I got the RM850x recently and swapped with RM650x yesterday, after I tested the ASUS CUV-NT with RM850x. Worth checking indeed, though.

I was suspecting if ASUS CUV-NT is known for being picky about certain transient behaviors/timings or timing of the PG signal, but didn't see that in any discussions. I'm hoping that other CUV-NT owners could chime in about the PSUs they're using, perhaps there's a relatively cheap PSU that is known to work with it.

Edit: Measured after shorting the PS-ON to Ground without connecting it to a computer, all within 5% tolerances.

I used the computer with the RM850x a little, updated the BIOS, replaced the BIOS battery (which was dead), and set fan monitoring settings to ignore in the BIOS (because with or without fans connected to the motherboard, the BIOS was giving an error about ventilation fan failure PC may overheat). The next day, I gave RM650x another try and it worked. Not sure what was the problem, but it is working now with RM650x.

When I plug in the USB 2.0 PCI card with NEC 720101 chip in any PCI slot, the computer doesn't post. But it is fully functional otherwise with NVIDIA FX 5200 PCI and Creative Audigy 2. It also has an on-board NVIDIA RIVA TNT2 (AGP).

Initially, I installed VIA 4in1 4.35 chipset drivers but after having extreme stuttering issues when Audigy 2 and IDE are being used simultaneously (tried PCI latency patch, moving the cards around to eliminate IRQ sharing, and removing FX 5200 altogether, none helped), I did a fresh install with VIA 4.17 drivers (based on a recommendation elsewhere on Vogons), without the latency patch, and set a generic driver for the PCI IDE (connected via StarTech IDE2SAT2, DMA option for the disk enabled from the device manager), and all stuttering problems went away even with FX 5200.

Interestingly, even with an 80-wire cable, the disk benchmarks are capped around 33MB/s.