Question 6 pin SATA to 8-way PWM splitter for radiator fans

[tm1736]

I plan on installing two 8-Way PWM Splitters to power a total of 12 radiator fans. One splitter to power 8 fans and the other to power 4. My questions are:

1. Should I connect both 8-Way PWM Splitters to the same 6 pin SATA cable going to the psu? Or should I use two separate 6 pin SATA cables - one for each 8-Way PWM Splitter? That is does one 6 pin SATA outlet supply adequate power for both splitters? And if so is one 6 pin SATA cable adequate to supply this power to both splitters?

Or 2. Can I use one Swiftech 8-Way PWM Splitter from one 6 pin SATA cable for all 12 fans by connecting Y-splitters to the 8-Way Splitter? This concerns me because it says up to 8 devices in the product description.

PWM Splitter:
https://www.amazon.com/gp/product/B00IF6R4C8/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Fans:
https://www.amazon.com/dp/B01N0GRQD2/ref=dp_prsubs_1

psu:
https://www.evga.com/products/product.aspx?pn=220-T2-1000-X1

 

[rubix_1011]

You can connect 2 of those SATA splitters to the same PSU cable that has multiple SATA connections. Fans pull fairly low power by comparison to other components. I don't know how you would connect both to the same SATA port unless you splice them together. Then, yes, you can still do this.

You can also do the second option.

Either of these will work assuming you connect fans to at least the first port which is what the PWM sensor reads from for all fans.

Question - why such expensive fans? I mean, those are good fans, but you can get equally good fans for much less.

 

[tm1736]

You can connect 2 of those SATA splitters to the same PSU cable that has multiple SATA connections. Fans pull fairly low power by comparison to other components. I don't know how you would connect both to the same SATA port unless you splice them together. Then, yes, you can still do this.

You can also do the second option.

Either of these will work assuming you connect fans to at least the first port which is what the PWM sensor reads from for all fans.

Question - why such expensive fans? I mean, those are good fans, but you can get equally good fans for much less.

Thanks for your reply,

The SATA cables that came with my psu each have one male 6 pin to connect to the psu with 4 female SATA connecters. If you click on the link to the psu there is a pic of all the cables and they are in the lower left hand corner.
https://www.evga.com/products/product.aspx?pn=220-T2-1000-X1

If you can't see the pic my SATA cables are similar to this cable:
https://www.amazon.com/d/Firewire-Adapters/Splitter-Extension-Multiplier-Seasonic-Modular/B078F137X1

My concern is that max current on the fans is (0.44A Peak). See
http://www.performance-pcs.com/dark...m-58cfm-black-edition-pwm.html#Specifications

So for 12 fans, if I understand correctly and amperage is additive, that's roughly 6A peak. Does a single 6 pin SATA outlet on the psu supply that much current? if so is a single SATA cable sufficient to supply that current by connecting each one of the splitters to one of the SATA connectors on the cable?

Does the cable divide the current evenly between two connected devices? Or is each device able to pull what it needs?

I already had the fans from my first build. I got them at the time because they were regarded as good quiet fans. I'm still a novice so I'm learning as I go. I'm just upgrading my mobo and cpu so I already have all the fans and radiators in place.

 

[rubix_1011]

Fans typically pull the most load at initial startup. I actually had to Google for your question and found this from the forums here long ago:
https://forums.tomshardware.com/thr...as-much-power-as-sata-power-connector.182242/

I don't have the electrical background to know if this is fully correct, but I have never had an issue running 8 fans from a single connection like this at full speed. I used to splice my fans all at full speed to power rather than PWM control.

 

[tm1736]

It would seem that from the standpoint of total amps I should be okay. But I would definitely rest a little easier with a more detailed explanation. Hopefully someone will provide one.

I'm pretty sure I should have no problems running 8 fans off of one SATA port on the psu using one SATA cable because the 8-Way Splitter is designed with 8 fan headers and a SATA power connector.

I'm just not as confident that I can add the other connector with 4 more fans to the same 6 pin SATA cable. Or similarly, I'm not as confident I can add Y-splitters and run all 12 fans from the one 8-Way splitter powered by one 6 pin SATA.

In the event that I don't get a more detailed response I will just use a separate SATA cable for each 8-Way Splitter. I may need to do that anyway since 8 fans are on the bottom radiator (push/pull) and the other 4 are on the top radiator. But I'm curious by nature and would still like to understand this much better than I do now.

Thanks again for all you help

 

[rubix_1011]

Swiftech is a pretty reputable liquid cooling company, I actually have that splitter you've listed. I haven't opened it to see what kind is on the circuitry inside, but would wonder/assume they account for buffering the power delivery system with in-line capacitors.

 

[Paperdoc]

Your total max load is not as bad as it first appears. The link you gave to the Performance PCs site says the current for each fan is 0.10 A max, with a peak of 0.44A. I believe that means that when running at max speed it will consume up to 0.10 A. The higher number VERY likely is the peak draw for about 1 sec at start-up, and such a pull for such a short time period can be ignored for most purposes.

The "PWM Splitter" you link to is what I would call a Fan Hub. This is a terminology thing, and many makers confuse the two types of devices. To me, a Splitter merely connects all its loads in parallel to the power and control signals from the host mobo fan header, and relies entirely on that header to provide all the power. It has NO access to an alternative power source. A HUB, on the other hand, draws all power for its fans from a direct connection to a PSU output, and no power from the mobo header. It does get the PWM control signal from the header and distributes that to all its fans, but this does not overload the header's PWM signal line. And certainly that's what the Swiftec device you showed is.

Connecting two of these to a single output connector from the PSU may not be a really good idea. Certainly the PSU can supply that much power with no issue. But the limit is in the construction of the SATA connector itself, and MAYBE the wires that feed it. SATA power output connectors normally are expected to supply up to 5A, so if you were to connect 12 of those fans to a single SATA output from the PSU (using a power Splitter?), their max load at full speed would be 1.2A, and the peak load at start-up might be 5.3A. That is very likely OK. IF you want to be cautious, that's easy. The simplest way to connect two of those Hubs to the PSU outputs is to plug each into a separate SATA output connector on the modular cable coming from the PSU. The SATA power cable sets with the PSU have four SATA output connectors on each cable set, so just use two of those, and the peak power (worst possible case scenario) for ONE Hub with 8 fans connected to all its ports might reach 3.6A. Absolutely no problem. I'm sure that, even if you use two SATA power connectors from the SAME cable set, the wiring of that set will handle this easily.

 

[tm1736]

I was thinking hub also but used splitter since that's what Swiftech called it. But I didn't really understand the distinction until I read your excellent explanation. Thank you for the clarification.

Additionally, thank you for clearing up my confusion in regard to how to power the hub. I think I will use a separate cable for each hub. Partly just to play it safe. But also because I have the cables and the ports free on my psu, and given that one radiator is on the bottom of my case and the other on the top, it seems to make sense from a cable management standpoint.

 

[tm1736]

Thank you both for taking the time to reply.

 

[Karadjgne]

Sata power connectors are rated at 54w/4.5A. So realistically, at 0.1A per fan, you could safely run 12 fans quite easily from a single Sata source. That said, power won't be the issue, the pwm will be. You can only split the pwm signal so many times before it starts loosing ability, it's not a particularly strong signal to begin with. If that 8way was using the pwm as a source to a powered relay, basically amplifying the pwm signal, then no worries but I don't see it doing that, just splitting the source 8x which is barely enough mA to actually register in the motor circuitry as a signal.

A 12" 18ga wire can safely handle @ 10A@ 12v DC, so with startup amperage as it is, you can use 2x Sata connectors on the same chain, powering 2 separate hubs, but I'd pull the pwm from separate headers not a splitter from a single header. Using SpeedFan you can set each header to respond to the same ISA address, so the signals will be identical even if the sources are different.

 

[tm1736]

Interesting, and thank you for taking the time to reply. That is something I had not considered and was not even remotely aware of. Do you think I will be okay if I keep it to 8 fans or should I look for a better hub? Any recommendations for a better hub?

 

[rubix_1011]

That Swiftech fan hub uses the reading from device 1 for the control, all others are controlled based on the PWM signal that is managed from this fan.

 

[tm1736]

That Swiftech fan hub uses the reading from device 1 for the control, all others are controlled based on the PWM signal that is managed from this fan.

I think the reading from fan 1 is just feedback to the motherboard. Somehow a pwm signal still needs to get to all the fans to regulate their speed. I think what Karadjgne is saying that the Swiftech 8-way does this by splitting the signal from the motherboard header.

 

[rubix_1011]

Correct, that is what I originally meant - header 1 is the only one providing the reading back to the MOBO, but yes, internally, the hub has to route that PWM command back to the other 7 headers.

 

[tm1736]

Sata power connectors are rated at 54w/4.5A. So realistically, at 0.1A per fan, you could safely run 12 fans quite easily from a single Sata source. That said, power won't be the issue, the pwm will be. You can only split the pwm signal so many times before it starts loosing ability, it's not a particularly strong signal to begin with. If that 8way was using the pwm as a source to a powered relay, basically amplifying the pwm signal, then no worries but I don't see it doing that, just splitting the source 8x which is barely enough mA to actually register in the motor circuitry as a signal.

A 12" 18ga wire can safely handle @ 10A@ 12v DC, so with startup amperage as it is, you can use 2x Sata connectors on the same chain, powering 2 separate hubs, but I'd pull the pwm from separate headers not a splitter from a single header. Using SpeedFan you can set each header to respond to the same ISA address, so the signals will be identical even if the sources are different.

It never occurred to me that I could even split the pwm signal from a header despite the fact that I was wondering what would be the best way to keep all the fans in sync. I will definitely go with a different header for each hub. I plan on going with separate SATA cables for each hub as well simply for better cable management. My concern at the moment is weather or not the Swiftech 8-way is a reliable device given that it's spreading the pwm signal rather thinly accross 8 fans? Just wondering if there might be a better option?

 

[Karadjgne]

Well if you assume (don't say it!) that Swiftech is comprised of a bunch of very intelligent and knowledgeable experts on the subject of pwm fans, headers, pumps, radiators etc then it's probably safe to assume they've done their homework and arrived at the conclusion that their designed 8way splitter hub is capable of carrying out pwm signal splitting without loss of signal. With a maximum of 8 devices. Meaning it's intended for upto a 480mm push/pull radiator fan setup or 2x 240/280mm rads to be in synchronous operation from a single header. Not intended for use with 12 fans, having splitters fed downstream from the hub.

I don't think they'd get many sales of an 8way pwm hub if it wouldn't run 8 fans. In a parallel setup. Arctic has gangable fans, you daisy chain the fan, but because it's serial, you are limited to 5 I believe before signal degradation.

 

[tm1736]

Well if you assume (don't say it!) that Swiftech is comprised of a bunch of very intelligent and knowledgeable experts on the subject of pwm fans, headers, pumps, radiators etc then it's probably safe to assume they've done their homework and arrived at the conclusion that their designed 8way splitter hub is capable of carrying out pwm signal splitting without loss of signal. With a maximum of 8 devices. Meaning it's intended for upto a 480mm push/pull radiator fan setup or 2x 240/280mm rads to be in synchronous operation from a single header. Not intended for use with 12 fans, having splitters fed downstream from the hub.

I don't think they'd get many sales of an 8way pwm hub if it wouldn't run 8 fans. In a parallel setup. Arctic has gangable fans, you daisy chain the fan, but because it's serial, you are limited to 5 I believe before signal degradation.

I think I'll give it a go then. Thanks for taking the time to reply. And thanks to everyone else that replied as well. Much appreciated!!!

 

[Paperdoc]

I think Karadjgne makes very good points. Surely there IS a limit to how many fans can share one PWM signal, and Jaradjgne has identified that is probably is about the 8-fan group that Swiftech has designed around. So your plan to use two such Hubs with connections to separate mobo case fan headers and SATA power output connectors is a VERY good one. If you configure the two fan headers in the same way (either using BIOS Setup or Speedfan or similar utility), they will all work the same.

You are correct about how the speed signals are used. The mobo automatic fan speed control system does NOT use the actual speed signal for ANY of its control functions. In fact, it is a TEMPERATURE control system that focuses solely on the temperature measured at a sensor in the mobo, and simply manipulates the fan speeds to whatever it takes to get the measured temperature to stay on target. But the header DOES use the fan speed signal for a different function - FAILURE detection. If it receives no speed signal (or, in some cases, a signal lower than some minimum threshold) It sends out an alarm to notify you that you have a problem that needs to be investigated. (In the case of the CPU_FAN header particularly, it MAY take more drastic action in a short time to shut down the entire system to prevent overheating of the critical CPU chip, even without waiting for that chip's temp sensor to show high temps.). Users of BOTH Splitters and Hubs need to take into account that these devices allow return to the mobo header of the speed signal of only ONE of the fans, and the others are ignored. That means the mobo cannot monitor ALL of the fans for failure. YOU need to check from time to time whether all the fans really are working properly.

 

[Karadjgne]

Cpu_fan has to be populated. Doesn't matter by what, it just has to have something in it that will register a certain rpm. Speedfan has the ability to change readable addresses per fan (or group). So it's feasible to setup all your fans, using cpu_fan and sys_fan to use the temps read from cpu. This'll put both the headers reading the same. Or you can change it up to read cpu and gpu. Or cpu and case, up to you how it's setup.
Warning: SpeedFan is the single most infuriating software to setup I've ever used. It's great at it's job, just a royal pain to get right and does take a certain learning curve. You will probably also need to set it up as a Windows task for startup to avoid the UAC and have it startup automatically at boot. You'll also need to set rudimentary fan control in bios.
Bios uses temp vs duty cycle for its curve. Ie: if the cpu is at 50°C it might use 60% fan speed. If you have 1000rpm fans, they'll be at 600rpm, if you have 3k industrials, they'll be at 1800rpm. If it's enough to keep temps in check, they'll stay that way, if not duty cycle will go up, so while bios temp is accurate, it's not always realistic, only as it applies to bios loads.

 

[tm1736]

Thanks you both for the additional information I'm really understanding all of this much better as a result. Everything is up and running and seems to be working well. I have the 4 fan radiator connected to the CPU_Fan header mainly because I can see those fans at a glimpse at all times and in particular Fan 1. I haven't installed Speedfan but I will give it some thought. At the moment I'm controlling all fans with the bios.

 

[Karadjgne]

SpeedFan is great. Wish the dev would have just stuck with a lite version for fans only and not included all the other monitors and stuff. I looked at it.. And moved on. But what it can do with fans is pretty amazing considering it's age. There isn't another fan program like it. Actually I don't believe there is another program anymore...

However, accolades aside, if you drink, bring a couple of shots with you, preferably doubles. SpeedFan is the single most infuriating program I ever had the pleasure of trying to figure out. There's no real instruction manual, you just gotta dive right in and figure most of it out while flipping tabs (there's only 3 you'll need), but once it's setup, it works like a champ. The only program like it comes with your motherboard software, but they are pretty basic comparatively. Only Asus fanXpert so far beats it, just purely on ease of use for asus mobo's.
You'll need to also create a windows task to start it automatically on boot, or continuously say 'Yes' every time the UAC pops up.

 

[tm1736]

Thanks I had Asus fanXpert on my last motherboard and liked it but ultimately just ended up using the bios for fan control. No because I didn't like it but mostly because I was trying to cut down on the number of processes constantly running in the background. Just about everything comes with some type of software now - mouse, keyboard, . . . As long as my temps are good I'm not too concerned if my fans aren't completely in sync. I'm guessing there won't be too much variation and that it won't make too much of a difference.

 

[Paperdoc]

Glad ti see you have it all working well for you.

 

[tm1736]

Glad ti see you have it all working well for you.

Thanks, and thanks again to everyone who replied.