Split one PWM to five fans and control speed?

[P0rthos]

For aesthetic appeal and because the summer ambient temperature in the room where my computer lives gets rather high I think I'll probably need up to five case fans to keep everything relatively cool. My issue arises from the fact that my Gigabyte H170N-Wifi only has one SYS_FAN header.
While I could drive them all from the PSU at constant full speed, I would greatly prefer to let the computer automatically configure the speed of all of the fans. To my understanding, splitters such as this should allow each fan to take power from the PSU and pulse width information from the motherboard to achieve the results I desire. However, after purchasing that cable for use with the three PWM fans that I currently own I have found that the fans run at high speed constantly. Adjusting speed via BIOS does nothing, and removing the four pin female part of the cable from the motherboard does not change a thing. It's pretty obvious that the cable is just allowing the fans to draw all possible power from the PSU and sending RPM info back for the motherboard to read but not adjust.
Is there a solution that will allow automatic adjustment of multiple fans from one four pin PWM header?

 

[Isokolon]

you have to disconnect the MOLEX connector from the PSU

however you gotta make sure the fan header is specified for enough power to power all of the fans connected to it
(should be somewhere in the manual)
otherwise you can buy a fan controller

but honestly, I have a sound dampened case and it gets 38-40°C hot in my room and I don't need more than 3 fans in my case...

 

[P0rthos]

I will probably need only three, but the case's aesthetic looks more complete with five. My logic is as follows: if there is a solution for three fans there must be one for five.
Anyway, I'm not certain that the header can handle outputting enough power for even three of the fans. The manual does not seem to mention any electrical information pertaining to the header, but I think I learned that the power output is insufficient when I had the three fans hooked up to a splitter without MOLEX before I switched to this cable and they started acting oddly. For instance, their LEDs were erratic and would change in light level, sometimes at boot they would fail to spin up, etc. These things do not happen when just one fan is connected to the header.
I am wondering whether there is a way to have the power drawn from PSU but speed changed by the motherboard.

 

[Isokolon]

if your case has a free 5'25 bay get a fan controller. you can hook the fans up to it and control the speed manually.
NZXT makes decent ones.

 

[synphul]

Maybe consider a fan hub similar to this one. It's powered by a sata power cable, the fan cable attaches to the cpu_fan header to get the pwm signal and sends it to the hub. The cpu cooler fan(s) and other case fans plug into the hub.
https://www.amazon.com/Swiftech-8W-PWM-SPL-ST-Way-PWM-Splitter-Sata/dp/B00IF6R4C8/ref=pd_sim_147_8?_encoding=UTF8&psc=1&refRID=65GAC57FY0K8NDW2J9YY

There are other similar devices but gives an idea of what to look for. I wouldn't recommend trying to run 5 fans off a single fan header on the motherboard using splitters (all 5 drawing power off one header). It's liable to damage it and then you'll be back to square one with no additional fan headers on your board. Using a pwm hub like the one I linked to you can set the fan curve in the bios and run all fans on the same curve.

 

[P0rthos]

Unfortunately I do not have any open ports for a fan controller. I could get an external one I guess if I wanted to do things manually.
That splitter looks pretty ideal, but a bit earlier I read that it isn't recommended to run fans on the same loop as HDDs and SSDs due to fluctuations in current caused by the fans (something like that anyway). Should I give the splitter its own dedicated SATA connection to the power supply or will it be fine to run off of one of the extras that connect the drives to power?