Replacing GPU fan - funky behavior

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Smitty2k1
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Joined: Tue Nov 13, 2018 4:50 pm

Replacing GPU fan - funky behavior

Post by Smitty2k1 » Tue Nov 13, 2018 5:19 pm

Hi all - sorry for the long post but I'm really stumped here!

I recently added a low profile 1050ti (https://www.gigabyte.com/Graphics-Card/ ... TOC-4GL#kf) to my mITX build. The case I'm using, Realan E-i7, has room for a pair of case mounted 80x15mm fans if I remove the GPU shroud and built in 50mm fan. So naturally I bought a pair of Noiseblocker 80x15mm PWM fans (https://www.blacknoise.com/site/en/prod ... hp?lang=EN) as I had experience using one previously to replace the stock fan in my Silverstone 450w SFX power supply.

The 1050ti I purchased has a mini 3-pin fan connector. I cut the power connector off of the stock fan and soldered it to a full size PWM fan connector leaving the PWM wire detached. I then used a 4pin Y cable to connect the two fans.

Booting up my system I noticed that the two Noiseblocker fans were spinning at incredibly high RPM. Some investigation led me to learn that my card has a minimum 30% fan speed that is BIOS locked and cannot be modified. No problem I thought, I'll simply add an in-line Noctua PWM 4-pin low noise adapter to the mix! Sure enough this brought the two fans down to a more reasonable (albeit not perfect) minimum fan speed.

To ensure stability, I loaded up Furmark to test for temperatures and tune the fan curve. However, the fans never increased speed, they simply maintained the same RPM. Using HWMonitor I confirmed that the GPU fan speed % was increasing, but the resulting RPM remained constant. The next thing I attempted was removing the low noise adapter and plugging the two fans directly to the GPU. Still got the same very high RPM at idle (30% fan speed) and I confirmed that the RPMs did increase under load with the increasing fan %. I also used MSI Afterburner to check to ensure I could manually select fan speed, which worked as expected (and was unable to go below 30% fan speed as locked in BIOS).

I have since tried the following:
1) Used a different Y cable, the first one I used had a tach wire for each fan that was leading to some oscillations. The next one I tried (Noctua) did not have a double tach wire but still did not allow me to change fan speeds with the low noise adapter.
2) Using the Y cable and low noise adapter plug the fans into a PWM motherboard header. This resulted in expected behavior, the fans were able to run between 0-100% and the RPMs scaled accordingly. I also tried Speedfan to see if I could automatically adjust the fan speed based on the GPU temperature, but alas the outdated Speedfan did not recognize my GPU. :(
3) I did some reading on the Noctua low-noise adapter and found that Noctua does not recommend a single adapter for two fans! So I plugged a low noise adapter into each fan, before plugging in the Y-cable. When plugged into the GPU this resulted in the same behavior - unable to control fan speed.
4) I feel that the mini 3-pin to PWM fan connector cable I built functions properly as I am able to read and adjust the fan speed of the Noiseblockers without a low-noise adapter in line.

So I'm stumped here - as far as I know the low noise adapter is just a resistor in series that should cause the fans to receive less voltage from either the motherboard or GPU header. As far as I know the adapter cable I built works properly. As far as I know using these PWM fans off of a 3-pin header shouldn't cause any unexpected behavior. I'm also surprised that at 30% minimum fan speed the two Noiseblockers spin SO FAST! I just checked and the stock fan from this GPU is 12V and 0.19A. The Noiseblockers are 12V and 0.13A so it makes sense they spin a little faster.

I think I can try the following but I don't really want to spend money:
1) Buy a mini 3-pin to 3-pin adapter cable
2) Buy the Noctua 3-pin low noise adapters
3) Buy a different set of low profile 80mm fans (3-pin)

Any other thoughts, ideas, tips, or things to troubleshoot would be greatly appreciated!

CA_Steve
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Re: Replacing GPU fan - funky behavior

Post by CA_Steve » Wed Nov 14, 2018 7:12 am

Welcome to SPCR.
The 1050ti I purchased has a mini 3-pin fan connector.
If it's a 3-pin connector, then the gfx card is using a voltage based controller (voltage +, gnd, rpm sensor). Since the gfx card is locked to 30% min fan speed, it will use the sensor feedback to push the voltage it thinks the fans need to get to this min speed.

The two best (or least worst) options are Speedfan (which didn't work) and using the mobo to control the fans. With the latter, you have PWM control, and can set a curve to follow CPU temp sensor. It's not perfect, but GPU use should track CPU use in games. You can use some monitoring utilities, like GPU-Z, to fine tune the profile.

Smitty2k1
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Re: Replacing GPU fan - funky behavior

Post by Smitty2k1 » Wed Nov 14, 2018 7:17 am

CA_Steve wrote:Welcome to SPCR.
The 1050ti I purchased has a mini 3-pin fan connector.
If it's a 3-pin connector, then the gfx card is using a voltage based controller (voltage +, gnd, rpm sensor). Since the gfx card is locked to 30% min fan speed, it will use the sensor feedback to push the voltage it thinks the fans need to get to this min speed.

The two best (or least worst) options are Speedfan (which didn't work) and using the mobo to control the fans. With the latter, you have PWM control, and can set a curve to follow CPU temp sensor. It's not perfect, but GPU use should track CPU use in games. You can use some monitoring utilities, like GPU-Z, to fine tune the profile.
Thanks for the response! However, I'm still confused as to why the RPM doesn't increase when I have the low noise adapter installed.

CA_Steve
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Re: Replacing GPU fan - funky behavior

Post by CA_Steve » Wed Nov 14, 2018 9:09 am

One possibility is the gfx card's fan controller isn't seeing/doesn't recognize the sensor information and so it goes to the default 12V max and stays there. Adding the LN adapter just lowers the 12V to something less and keeps the fans at the resulting lower rpm.

Abula
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Re: Replacing GPU fan - funky behavior

Post by Abula » Wed Nov 14, 2018 10:44 am

GPU fans are not always standard, i had an issue with GTX780 trying to use accelero III and never could lower the rpms, but accelero IV had this fixed, so its not always plug n play on the gpus, more recent like 980ti and 1080 were fine using any PWM fan.

Smitty2k1
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Re: Replacing GPU fan - funky behavior

Post by Smitty2k1 » Thu Nov 15, 2018 9:04 am

CA_Steve wrote:One possibility is the gfx card's fan controller isn't seeing/doesn't recognize the sensor information and so it goes to the default 12V max and stays there. Adding the LN adapter just lowers the 12V to something less and keeps the fans at the resulting lower rpm.
Hmm that's interesting, hadn't considered that as a possibility!

I've gone all out and purchased a pair of slim 80mm Cooler Master fans (R4SPS20AKGP) that are 3-pin instead of PWM. Hopefully I can use these at a reasonable fan speed to help with sound. I've also purchased a set of the 3-pin Noctua low-noise adapters to see if that irons out any funky behavior with the Noiseblockers.

My "cheap" $120 1050ti purchase has turned into nearly $200 worth of parts... 4 fans, two sets of rubber mounts, a set of low noise adapters, a y-cable, and two incorrect mini 3 pin adapters.

Smitty2k1
Posts: 5
Joined: Tue Nov 13, 2018 4:50 pm

Re: Replacing GPU fan - funky behavior

Post by Smitty2k1 » Thu Nov 15, 2018 9:05 am

Abula wrote:GPU fans are not always standard, i had an issue with GTX780 trying to use accelero III and never could lower the rpms, but accelero IV had this fixed, so its not always plug n play on the gpus, more recent like 980ti and 1080 were fine using any PWM fan.
Yeah I think that's part of the issue here - the 1050 ti I have is locked in the BIOS to a minimum of 30% fan speed, even if I attach different fans it still tries to push out 30% fan speed.

CA_Steve
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Re: Replacing GPU fan - funky behavior

Post by CA_Steve » Thu Nov 15, 2018 11:10 am

Smitty2k1 wrote:My "cheap" $120 1050ti purchase has turned into nearly $200 worth of parts...
Considering a new MSI Gaming X is ~$180-190, yeah.

Smitty2k1
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Re: Replacing GPU fan - funky behavior

Post by Smitty2k1 » Thu Nov 15, 2018 11:25 am

CA_Steve wrote:
Smitty2k1 wrote:My "cheap" $120 1050ti purchase has turned into nearly $200 worth of parts...
Considering a new MSI Gaming X is ~$180-190, yeah.
Not low profile though :)

I have a super small PC that can only fit a low profile GPU, I was using it with a Ryzen 2400G APU and figured "For $120 why not upgrade?"

CA_Steve
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Re: Replacing GPU fan - funky behavior

Post by CA_Steve » Thu Nov 15, 2018 3:38 pm

Smitty2k1 wrote:..and figured "For $120 why not upgrade?
Heh - I think all of my "..and then I had to do this" projects started this way. :)

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