Molex led strips and fan splitter power consumption

JayGau

Distinguished
Dec 20, 2016
101
19
18,585
Hi everybody,

I have a strange problem. I have recently mounted a new desktop with new hardware (Geforce GTX 1060 graphic card, FX-8350 cpu, 32gb ram, 750gb SSD sata drive) and to make it looking good I installed a 2 led strip kit powered with a molex cable. After that I installed 2 new fans (for a total of 4 in the case) but since my motherboard only has two 3-pin outputs I bought a molex-to-3x-3pin splitter and I plugged it on the same molex cable than the led strip kit in order to power the two new fans.

The problem is that when I turn on the led strip the fan speed (of the two new ones plugged in the same molex cable than the strips) goes down very much and if I boot the computer with everything turned on it has to boot twice before to finally reach Windows login (like something is draining too much power). Before I installed the fan splitter it was working just fine (with the led kit only).

I have a corsair 650W psu, so it should be more than enough to power some led strips and a couple of fans. Maybe this single molex output is not powerful enough to power both the led strips and the fans? Should I use a 3pin-to-3pin splitter for the fans instead of the molex-to-3pin? Because it is clear that they cannot work at the same time at full capability with this connection set up (for some reason that I don't understand).

Any idea someone?
 

JayGau

Distinguished
Dec 20, 2016
101
19
18,585
Hi!

Here are my specs:

-AMD FX-8350 8-core 4GHz CPU
-Crucial Ballistix Sport 4x8GB (32GB)
-Gigabyte AM3+ AMD 970 Motherboard
-Gigabyte GeForce GTX 1060 WINDFORCE OC 6GB
-Crucial MX300 750GB SATA Internal Solid State Drive
-CORSAIR CX-M series CX650M 650W

And about your other question no I am not overclocking anything on the PC. Also my usb ports seems to experience some problems too since I plugged in those strips and fans but maybe it's not related. On another forum someone said that the strips and fans are different hardware and should not be plugged on the same cable. Is it a possible explanation?

Thank you very much for your quick reply by the way!
 

JayGau

Distinguished
Dec 20, 2016
101
19
18,585
I finally bought a 3pin-3pin splitter cable and it works just fine. The PC doesn't struggle anymore and boots in 10 seconds. Also the fans seem to turn at constant speed whether or not the led strips are turned on. I guess the molex daisy chaining with fans and leds on the same cable was not a good thing to do.