PWM fan headers problem

[XtremePotato]

A quick layout of the system:
I7-4790K
4Gb transcend RAM 1600Mhz
EVGA supernova 1000W P2 PSU
Gigabyte z97X-Gaming G1 WIGI-BK ( this one http://www.gigabyte.com/products/product-page.aspx?pid=4980)
BIOS version: F5 (the latest)
Windows 8.1 64-bit
Running a custom water loop

The top rad is running 6*120mm Corsair Fan, High static power edition. 3 of them are connected with a PWM fan splitter (that one specifically

http://www.newegg.com/Product/Product.aspx?Item=N82E16812311001&cm_re=fan_splitter-_-12-311-001-_-Product

one of the 5 headers supplies power to the Water block lightning (Swiftech Apooge XL ) the 5th header is empty, the 3 other fans on the rad have the same configuration with another one of those splitters except 2/5 headers are empty, Both of the splitters are connected to PWM motherboard fan headers, the CPU FAN header works perfectly and can be managed thorough the SIV (system information viewer by gigabyte), The other splitter is connected to the CPU_OPT fan header where there is absolutely no control of any sort, even with manual option enabled, custom curve... nothing works no matter what i plug in there... Except a single PWM fan, I tested the header just to if there is no power delivery or any control. It works perfectly with a standalone PWM fan, Same problem with  the System 4 and 5 fan headers, the pump is PWM but no control of any sort, runs at max. I tested the header with a random PWM fan I have, they work perfectly... Am I missing something here) 
 
(here is the SIV running in quiet mode 

)

I troobleshoot-ed in every possible way.. even through the BIOS... Contacted gigabyte, no useful reply anything connected to the CPU FAN header works like a charm, other headers... not so much (Only a single PWM fan)

[Hb27]

if you check page 27 and 28 of your manual

 

http://download.gigabyte.asia/FileList/Manual/mb_manual_ga-z97x-gaming-g1-wifi-bk_e.pdf

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you will see that

 

CPU_FAN is really PWM control as it has speed control on the 4th pin

 

SYS_FAN1/2/3/4/5:​  are all voltage control and have the speed control on the 2nd pin (NOT PWM)

 

CPU_OPT  is also voltage control and has the speed control on the 2nd pin (NOT PWM)

 

 

so in reality your motherboard only has 1 pwm fan header...

 

you can get a PWM fan hub and connect all fans there and connect the fan hub to the cpu header to be able to control all fans via PWM

 

http://www.amazon.com/Swiftech-8-Way-Splitter-Power-Connector/dp/B00IF6R4C8/ref=pd_bxgy_147_img_z

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http://www.amazon.com/gp/product/B00VNW556I/ref=s9_simh_gw_p147_d25_i1?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-2&pf_rd_r=0T33KD11C8E3R63VAQWG&pf_rd_t=36701&pf_rd_p=2091268722&pf_rd_i=desktop

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hope this helps!