Is a fan hub necessary for 5 fans installed on a GPU mining rig?

[Didz]

Hi Bitcointalk community,

I would like to know if you guys are using a fan hub on your mining rigs for safety measurements so the load can be evenly distributed and reduce the load for the Header itself.

In my particular case, I have 5 of these fans (P12 PWM PST CO):
https://www.arctic.de/media/05/64/2f/1583824874/spec_sheet_P12_PWM_PST_CO_190328_r6_EN.pdf

I want to plug these 5 fans on the Chassis Fan Header on my motherboard PRIME Z390-A ASUSTeK.

Each fan has a Voltage/Current of 0.08 A/12 V DC.

In the instruction manual of the motherboard PRIME Z390-A ASUSTeK, it's written for the CHA_FAN1:

Header Max. Current 1A and Max Power 12W

So if I want to calculate the total watt of 1 fan I do: 0.08 X 12 = 0.96 Watt. So I multiplied it by 5 (for 5 fans) and it gives me 5 X 0.96 watts = 4.8 watts total for the 5 fans.

So if I plug these 5 fans on the CHA_FAN1 Header on my motherboard then it will be at a total of 4.8 watts which is way less than the Max Power 12W. Plus, the total Amp for the 5 fans is 0.08A X 5 = 0.4 A which is less than the Max. Current 1A.

Why I am asking the question? Because I opened a chat with Asus and a representative wrote this to me:

Since the fans only has 0.08A per piece, there is a chance that the Daisy chain will work on each header. But for safety measurements, I do advise using a Fan hub instead so the load can be evenly distributed and reduce the load for the Header itself.

In that case, I was thinking to use 2 fans on one chassis fan header and 3 fans on the other chassis fan header on my motherboard.

Anyway, I really don't understand why there should be any problem to connect these 5 fans on one fan header of my motherboard?

Probably something I don't know. Can someone enlighten me?

Thank you

[1714821348]

1714821348

[1714821348]

1714821348

[philipma1957]

your board has many fan headers why do all fans on 1?

If it fails every fan fails.


I see 4 fan headers on it.
one for the cpu cooler and 3 others

[Didz]

You're right, actually it has only 2 chassis fan headers, I don't know if I can use the other fan headers (probably yes I guess). philipma1957 do you use a fan hub on your rigs?

[Didz]

I don't think I can use the EXT_FAN it's a 5 pins

[sxemini]

I use this Fan hubs for my rigs. Work for years without any problem.

https://www.ebay.com/itm/123261169717?chn=ps&norover=1&mkevt=1&mkrid=707-134425-41852-0&mkcid=2&itemid=123261169717&targetid=1112777663470&device=c&mktype=pla&googleloc=9042849&poi=&campaignid=10203814770&mkgroupid=101937411037&rlsatarget=pla-1112777663470&abcId=1145991&merchantid=110523639

[miner29]

You can run them off the available spots...just chain them off one another. 

Or you can slap a fan controller on it.  I just wire up the fans and let them run.  The difference in power is of little concern.

[Didz]

Thank you everyone!

[adaseb]

Since those are low power fans you can probably get away with using the headers. However if you are planning on pulling more than 1 AMP then don't connect it to the headers because you will burn a spot on the motherboard.

I had a rig where I needed like 4-5 high speeds fans connected. These fans weren't low power and couldnt use the header for all of them. So what I did was basically just connect it to the auxilary CPU plug on the PSU (Some PSUs have 2 CPU connectors) and each fan was plugged in directly into the +12V and GND. I even bought the harness and it was a clean setup. This way I knew it would never melt. Just had to modify the wires a little bit and lost control over fan speed however that wasn't an issue for me.

[Commie]

Sorry for a bit of offtopic, but these fans won't do you much good. I assume you want to effectively cool your GPUs, low power fans aren't the solution. Look into 0.6 - 0.8A fans like Delta. They are expensive but then they move lots of air. If you decide to buy them for your rig I'd suggest to aim for 140-150mm fans instead of 120mm as you will be able to run them on lower revs for the same result and they will be much quieter.

[Didz]

Sorry for a bit of offtopic, but these fans won't do you much good. I assume you want to effectively cool your GPUs, low power fans aren't the solution. Look into 0.6 - 0.8A fans like Delta. They are expensive but then they move lots of air. If you decide to buy them for your rig I'd suggest to aim for 140-150mm fans instead of 120mm as you will be able to run them on lower revs for the same result and they will be much quieter.

Thank you Commie for your advice!

Actually I have a big Mitsubishi 24,000 BTU Commercial AC so the fans I bought, the P12 PWM PST CO
https://www.arctic.de/media/05/64/2f/1583824874/spec_sheet_P12_PWM_PST_CO_190328_r6_EN.pdf
are good just to move enough air, as you can see the temperature of my GPUs before:



and after

[Commie]

Sorry for a bit of offtopic, but these fans won't do you much good. I assume you want to effectively cool your GPUs, low power fans aren't the solution. Look into 0.6 - 0.8A fans like Delta. They are expensive but then they move lots of air. If you decide to buy them for your rig I'd suggest to aim for 140-150mm fans instead of 120mm as you will be able to run them on lower revs for the same result and they will be much quieter.

Thank you Commie for your advice!

Actually I have a big Mitsubishi 24,000 BTU Commercial AC so the fans I bought, the P12 PWM PST CO
https://www.arctic.de/media/05/64/2f/1583824874/spec_sheet_P12_PWM_PST_CO_190328_r6_EN.pdf
are good just to move enough air, as you can see the temperature of my GPUs before:



and after

Glad it works for you. However, these profits aren't going to last forever and using AC to cool your rig might send you into negative profit numbers

[nsummy]

I have nearly the same exact motherboard (prime z-270a).  You could connect all fans to the same header, no problem.  The reason you would want to use multiple headers is for control.  For example, on my case I my 3 front intake fans one cha_fan1  and my back exhaust fan on cha_fan2.  Just grab a fan splitter.  Amazon is full of them: https://www.amazon.com/Splitter-TeamProfitcom-Computer-Extension-Converter/dp/B07TRV6XZX/ref=sr_1_16_sspa?crid=VL1GFHHF8CIC&dchild=1&keywords=3+to+1+fan+splitter&qid=1621031766&sprefix=3+to+1+fan+%2Caps%2C216&sr=8-16-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExODBFM1VaVlkzVk9KJmVuY3J5cHRlZElkPUEwMzQzODUzMlE3VDZLWEU2S0FYMyZlbmNyeXB0ZWRBZElkPUEwMTcxMzI3TE9PODg2R1U0QzRFJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

If you haven't already, be sure to go into the bios and run the fan utility.

[Didz]

Sorry for a bit of offtopic, but these fans won't do you much good. I assume you want to effectively cool your GPUs, low power fans aren't the solution. Look into 0.6 - 0.8A fans like Delta. They are expensive but then they move lots of air. If you decide to buy them for your rig I'd suggest to aim for 140-150mm fans instead of 120mm as you will be able to run them on lower revs for the same result and they will be much quieter.

Thank you Commie for your advice!

Actually I have a big Mitsubishi 24,000 BTU Commercial AC so the fans I bought, the P12 PWM PST CO
https://www.arctic.de/media/05/64/2f/1583824874/spec_sheet_P12_PWM_PST_CO_190328_r6_EN.pdf
are good just to move enough air, as you can see the temperature of my GPUs before:



and after

Glad it works for you. However, these profits aren't going to last forever and using AC to cool your rig might send you into negative profit numbers

Hopefully my electricity cost is 0,07$/kWh and my AC has an automatic energy-saving operation i.e. the room temperature is automatically adjusted in order to maintain a fixed effective temperature, cooling operation is performed a few degrees warmer than the set room temperature once the temperature is reached.

I have difficulty to envision negative profit numbers. Let's simply take for example three 480 cards, from the website whattomine.com, mining ETH, it generates $12.51 in revenue per day (in date of May 15th 2:22 P.M. Easter Time) and with my 0,07$/kWh, it costs 0.71$ of electricity per day. I calculated my AC cost me in average 4$ per day.

So in this hypothetical example, the total electricity cost from the mining rig + A.C. = $4.71/day or
37% of the revenu goes to pay the electricity in this example but in reality I have much more than 3 GPUs so my actual electricity cost percentage which I monitor and calculate with my Power Distribution Units is around 5% of my total revenue.

There will be EIP-1559 in July which could impact negatively ETH mining revenues (-30%) and then next year ETH 2.0 will make it impossible to mine ETH but even when I look at the second most profitable coin to mine with GPUs, my electricity cost percentage will still remain very low.

I agree there's actually a frenzy around crypto mining but it is a really profitable business!