Fans

Been chatting with Grok and Brave AI tonight about my Novatech BB940016 2019 i5 build wrt fans. There are 3 fans in the case in some sort of hybrid wiring config with Sys_fan only has 2 wires connected to the header and as far as I can tell by some clever wiring 2 fans or all 3 are also connected to a PSU molex.

Grok has been giving me the hard sell to get a PWM splitter and attach new fans to the one Sys_Fan header on the motherboard. It only has one Sys_fan and CPU_Fan. Grok is recommending the Arctic P12 Pro x 3 to replace the Novatech stock fans as they might be noisy by now - they aren't, in fact I only hear the CPU fan revving up when booting.

So Grok is saying it is safe to attach 3 x P12 Pro Fans to one header via a splitter. I wasn't sure so got a second opinion from Brave AI. Both agree that the header has a limit of 1A current draw and stock fans have a draw of approx 0.18A so I could attach 3 Novatech Stock fans.

But as Brave AI reminded me the current draw for the P12 Pro is 0.33A as stated by Arctic but Cybernetics has tested the P12 and recorded 0.39A current draw. So 3 x P12 fans would by 1.17A overloading the Sys_fan header and possibly damaging the header and motherboard.

Conclusion Brave AI saved me from buying 3 x Arctic P12 Pro fans, a PWM splitter and possibly a new motherboard after a couple of months or shorter.

I could use the P12s as is wired now with the molex supplying the 12v grunt but these 3 Novatech stock fans are doing well. Grok was concerned that the PWM wasn't working correctly because only pin 1 (GND) and pin 2 (Speed voltage) of the sys_fan were connected.

Moral: Dont trust a bot without second opinion.

my mobo can provide enough amps for multiple arctic p14 fans. some others can't, The Arctics can be daisy chained. If you need multiple new fans get a fan hub which connects to a spare sata power connector.

Also stop using grok and brave ai. Most are trained by humans.

Silly question but what issue are you trying to solve? It sounds like your current fans are not noisy and are presumably working ok. Is this just because you feel like replacing them or is there a problem that you need to fix?

In reply to a post by ian72:

Silly question but what issue are you trying to solve? It sounds like your current fans are not noisy and are presumably working ok. Is this just because you feel like replacing them or is there a problem that you need to fix?

Due diligence mate. The PC is 7 years old most manufacturers like Arctic only provide a six year warranty. So like a boy scout I am being prepared.

I also emailed Novatech and they have come back with 2 x 140mm fans in front and 1 x 120mm in rear exhaust. There's something Grok and Brave AI didn't know.

So you’ll be replacing the disks, memory, processor, motherboard, heat sink, and case too? Presumably they are also out of warranty. Or you could just buy a new PC which will be much cheaper than replacing everything.

Disks possibly but mainly stuff with a known failure rate. A replacement PC of similar spec is about £649 with no OS and 8gb of DDR4 from Novatech so I would have to take my 32gb from old PC to match spec. The motherboard is Ultra Durable and I am hoping it lasts until this memory/ssd price crisis ends, if ever.

Cheaper to upgrade the PSU and fans when they fail than a whole new PC. Although I suspect your comment was a bit tongue in cheek.

Due diligence mate. The PC is 7 years old most manufacturers like Arctic only provide a six year warranty. So like a boy scout I am being prepared.

Fair enough. Personally with multiple fans in a case and no visible issues I would just keep running them - probably get 20 years out of them but if you are concerned about a potential failure and the knock on effects of an over heating system then I can see why you would look to replace. I am not sure I have ever seen many fan failures in over 30 years of working with IT.

Does seem a bit ott to replace stuff just out of warranty.

My XP machine is well over 20 years old and still running.

In reply to a post by ian72:

I am not sure I have ever seen many fan failures in over 30 years of working with IT.

I have seen a couple but mainly 80mm fans that just stop turning. 120/140mm fans seem more resilent.

Edited by Banger (Thu 26-Mar-26 18:35:27)

I’m not sure it’s a big deal to source and replace a fan if it fails. No point in doing so whilst it’s still working.

But, like you, I’ve never known a fan to fail - and that years of looking after hundreds of computers.