Connecting SilentiumPC Zephyr 120mm & 100mm Fans to ASRock H55M/USB3 R2.0 Motherboard: Safe?

Hello. I intend to replace 2 fans on my computer (on the front and back) because the current ones are extremely loud. A friend recommended me SilentiumPC Zephyr , one 120mm on the front to inject air and the other 100mm extruding on the back of the housing. And here my question, or such cluster for 2x 3pin for a pair of zlotys is enough for me to connect these 2 fans to one connector on the main board (PWR_FAN1)? Currently, one fan (at the back) is connected to this input, while the one on the front is connected via MOLEX to the power supply. I read on various forums that for some it works and hook up even 4 fans and I also read that if the board has a weak power section, connecting 2 fans can cause burning.

My computer's specifications:
Processor: i5 760
Graphics card: Radeon HD5770 1GB
Motherboard: Asrock H55M / USB3 R2.0
RAM memory: 2x 2GB RAM DDR3 Hynix
Power supply: ENERMAX PRO82 + EPR385AWT
Enclosure: Fever AC09A-BK / BK ACHILLES PPFC400

You have 3 connectors for fans - two above and one below how well I checked your mobo.

Yes, only the top one is occupied by the CPU cooler. At the bottom there is also one but it is 4-pin and for these fans I need a 3-pin so all I have left is the PWR_FAN1 connector on the board.

Connect the 3 pin fan to the 4 pin connector, it will fit and will work properly.

I honestly didn't know that you could connect a 3-pin plug to a 4-pin connector One more question, if I connect, for example, the rear fan with a 3-pin connector and the front fan with a 4-pin connector, then both will rotate at maximum speed? I don't want to have it too loud and I think it would be enough if they were working at 50% of maximum speed.

I think if you step on, you can check it. I have no idea what controls the fan speed on your board. If it allows PWM or DC regulation on this connector then you will be able to regulate the speed of this fan. If it allows only PWM regulation then you will have 100% RPM (full supply voltage 12V without regulation). After connecting, you can check in the BIOS whether it is possible to set the RPM control mode (sometimes PWM / DC or PWM / DC / AUTO settings). For the 3pin fan, the DC mode is correct.

I intend to buy the fans so I don't have any way to check it yet. In the BIOS I have the "Chassis Fan Settings" option which I can set to 2 modes "Full on" and "Manual Mode" in which I can set Level 1-9. This setting applies to the 3-pin connector or the 4-pin connector at the bottom of the board and only for fans with the PWM function? Because if only for such I will probably look for a fan that I can control from the bios level so that it is not too loud.

Chassis Fan is a socket at the bottom of the board and it can be controlled. The manufacturer has not revealed anywhere that it supports the control of 3-pin fans. The upper Power Fan socket is basically used to monitor the power supply fan (by design), it has no speed control.

So just when I attach a 3-pin fan to this 4-pin connector, will it always spin at 100%? Will it be impossible to regulate the speed or automatically adjust depending on the temperature in the housing? Because if so, I prefer to add a few zlotys to e.g. Arctic F12 PWM Rev. 2 and be able to regulate the rotational speed and possibly buy the other one with 3 pins without regulation and let it spin at 100%.

Yes or no - if the board supports DC regulation then you will also adjust the speed on 3pin, if only PWM - then no.

There is no way to check it? If I'm not sure I will probably buy with PWM regulation. Later I will try to connect the fan (3pin) to the bottom of the socket, which I have on the back of the case and try to change these levels in the BIOS, maybe I can see the difference in speed

I connected this fan to this 4-pin socket at the bottom of the board, changed the levels in the BIOS and did not notice any difference in the fan speed. So probably the 3-pin will not adjust.
In that case, I will buy a PWM fan on the front and set it at about 50% and on the back I will buy a regular 3-pin fan and let it spin at 100% This is probably the only sensible solution, I hope it will be quieter than it is today.

See, you've found a way yourself. Simple and effective. You can also buy a quiet enough fan that its 100% was not bothersome, buy a grommet from molex to a 3-pin socket enabling the fan to be powered from 5V, or you can still buy an additional speed controller for a few zlotys and plug it between the plate and the fan (to choose , to color).

Thanks so much for your help. I will buy these, I think SilentiumPC Zephyr 120 , they are not super efficient but have a low noise level, I think that they are enough for my computer. If they are too loud, I will buy a speed controller.