Percentage fan curve - two temperature readings at the same time - fan hysteresis

Hello,

I'd like to request 3 key features that are in my opinion essential to a software like Corsair Link, which is frankly the best of its kind right now, however imperfect.

I have 6 fans total including the radiator fans.

5 are PWM and 1 DC only :

- 3 Corsair HD140 RGB

- 2 Corsair HD120 RGB

- 1 BitFenix Spectre Pro Blue LED 200 mm

All of them are hooked up to a Corsair Commander Pro.

1) Now I have seen screenshots of Corsair Link 4 showing custom fan curves in percentage, whereas mine are all in RPM. It's a complete hassle to create a curve that way. I didn't have enough headers on my motherboard for all my fans, and the software that controls them is atrocious, so I bought the Commander Pro, and I had high expectations for the software.

If there isn't currently a way to change fan curves to percentage, it should really be considered as all software that control fans I encountered had this.

2) I have seen this request on many posts on this forum as well as many others, years apart, and yet it's only available on shady looking impossible to use without tutorials programs such as Speedfan or SIV.

It's the ability to set fan speed according to both CPU and GPU temperature readings at the same time. Whichever gets hotter first, the fan would go up.

I gave SIV a try, but the interface is extremely poor, and it's unbelievably unintuitive and complicated for what it's supposed to achieve. Plus it doesn't show the fan curve in percentage, only RPM :(

3) Finally, it would be terrific if some hysteresis was implemented, 2 to 5 seconds would do the trick. Because all my fans are set to the CPU package temperature right now, so they go crazy very often. It would be of tremendous help to add this feature.

Thank you for reading

This was something I actually looked into: giving end users a choice between setting up custom curves using RPM or %. The reason no toggle exists for this is interesting.

 

Surprisingly, it has to do with the hardware in each product we have that controls fans. Some firmware can only handle PWM %s; some firmware can only handle RPMs.

So you mean that some Commander Pro's are capable of handling PWM and some others only RPM ? It's the luck of the draw then ?

Thank you for reminding me about this! I've wanted this feature for a long time and for some reason I forgot about it. And I agree - this is a good feature to have. I'll put in a request for this.

Great, really appreciate it :)

If I'm not mistaken, a firmware update for CLCP is coming within the next month that may improve the hysteresis on the fan speeds. If that doesn't fix your problem, circle back with me and we'll reopen the issue.

Alright, thank you.

No. Commander Pro specifically uses RPM.

 

But we have some coolers that use PWM, and others that use RPM.

So the fans are the problem ? Because when I plug the fans of my motherboard or my *cough* CPU AIO cooler from another brand *cough*, the controls are in percentage on both software.

The fans aren't the problem. It's the controller ICs we use between different products.

I'm trying to understand your limitation, please help me clarify a few things.

Your current limitation is with the controllers in different of your products, ok.

Does those products include fans? I am here only mentioning fans, and not any other product using fan headers (like cpu pump).

My understanding of how fans are controlled is that by either DC modifying, or using the fourth pin with PWM, you can specify a percentage to use. My motherboard can run any fan I have with either DC or PWM using percentages.

If what I am saying is correct (and it's a guess), does that mean that the RPM limitation is there only because of non-fans products using RPM?

If so, would making an option for us (like the recent one where we can configure between 3/4 pin) where I'm saying that "fans 1 to 6 are fans I swear" allow me to use PWM (percentages)?

I'd love to have this option. I always wondered why Link bothered to use RPM (and had to guess what RPMs are given by trying percentages until meeting the correct one).

My guess is that the hardware controller on the Commander Pro takes a target RPM and then adjusts the PWM signal to keep the target RPM ... and it may specifically be in the part of the command set that allows you to set a fan curve with an alternate command that does allow you to set a fixed percentage (but no curve).

What would, IMHO, be ideal is if Link tested the fans for their min/max speeds and then remembered it (tools like Asus' FanXpert do this). The software could then display the fan curve as percentages and then, through a wee bit of math, abstract the commands that require RPMs at the controller level. After all, there's no problem that cannot be solved with another layer of abstraction. ;-) Perhaps a stop along the path to this panacea would be to allow the user to specify the max RPM for the fan (we'd have to test it ourselves or enter based on the spec sheet) and then it'd do the math - the active fan testing would be a bit more involved to implement.

But setting those fan curves by RPM is paaaaaaainful. Especially when the fan maxes at 1500 RPM ... so you have 2500 RPM worth of emptiness. And then moving them 1 degree at a time. The arrows make it better but patience is not one of my virtues.

It's still in the works, but slow going. We've been aggressively prioritizing fixing bugs in the software.

Bug fixes are awesome! Definitely prioritize that over new features; totally get it.

But ... it'd be really cool if you could also do control based on temperature deltas. Simple deltas between two values might even be feasible in the firmware (not sure how capable it is but I think it could be done with an Arduino ... I'm using that as my baseline which may not be fair).

My guess is that the hardware controller on the Commander Pro takes a target RPM and then adjusts the PWM signal to keep the target RPM ...

I don't think Corsair cannot directly control PWM through their firmware. You can in the software set a selected percentage.

If my guess is correct, letting us use PWM is really simple.

If Corsair indeed used an hardware controller that only takes RPM as an input, then tries to figure out which percent of either DC or PWM gets that RPM (using trial and error I guess), to eventually control the fans... That's an odd decision. Having no direct control on what you are sending through the fan pins? Weird.

I'd love to open the unit to see what's inside, but it's too expensive to be curious!

I don't think Corsair cannot directly control PWM through their firmware. You can in the software set a selected percentage.

If my guess is correct, letting us use PWM is really simple.

If Corsair indeed used an hardware controller that only takes RPM as an input, then tries to figure out which percent of either DC or PWM gets that RPM (using trial and error I guess), to eventually control the fans... That's an odd decision. Having no direct control on what you are sending through the fan pins? Weird.

I'd love to open the unit to see what's inside, but it's too expensive to be curious!

No ... what Corsair Dustin has been alluding to is that the RPM control is a limitation of the IC itself. Like I said, my guess is that the commands specifically to set a custom fan curve actually take, as input, target RPM and the device controls the PWM to hit that target fan curve. Working with these little devices is sometimes weirder than a normal person would think. They are designed by electrical engineers, who also tend to be a little weird. Mostly it's due to the very limited processing and memory available on those devices.

Now, I've not opened it up to see what chip they are using but I have done device programming like this before and for there to be a wonky crazy limitation on the actual controller doesn't come as something that's out of the realm of believability. In fact, once you've programmed a couple of these devices, it's pretty darn believable.

No ... what Corsair Dustin has been alluding to is that the RPM control is a limitation of the IC itself. Like I said, my guess is that the commands specifically to set a custom fan curve actually take, as input, target RPM and the device controls the PWM to hit that target fan curve. Working with these little devices is sometimes weirder than a normal person would think. They are designed by electrical engineers, who also tend to be a little weird. Mostly it's due to the very limited processing and memory available on those devices.

Now, I've not opened it up to see what chip they are using but I have done device programming like this before and for there to be a wonky crazy limitation on the actual controller doesn't come as something that's out of the realm of believability. In fact, once you've programmed a couple of these devices, it's pretty darn believable.

Fair enough, those things are often not done with the same logic us non-electrical engineers have.

The ability to set the fans running at a specific percentage is still here, however.

But I'd rather have fan hysteresis first, if I could pick.

Anyway thanks for the explanations :)

Welcome folks.

I have a problem with a Commander Pro, which could be resolved by adding percentage curve.

I have new EK Vardar Evo fans and setting rpm in Corsair Link results in slowing and speeding up those fans and this is really not good. I presume fans have some sort of IC inside that is doing similar thing to Commander Pro rpm controller. If there is some sort of solution it would be great.

Here fans are set to 1200 rpm and they fluctuate in this manner constantly.

Thanks in advance

P.S. And hysteresis setting would be really great.

It's the ability to set fan speed according to both CPU and GPU temperature readings at the same time. Whichever gets hotter first, the fan would go up.

Sorry for bringing this old thread up.

I just got my hands on a brand new Commander Pro and started setting up fan curves using iCUE v4.

I don't know if I'm making a mistake or this feature is still not available, but I would like to know if a fan speed can be controlled based on two or more sensor values?

For now, what I have realized is that more than multiple temperature inputs for fans speed control, the most required features are the hysteresis.

Yes, this would be good and is probably long overdue. Other normal control variables like GPU temp can still shift by a large amount as the card drops voltage on loading screens, etc. You don't really want the fans to drop and spike again for that period. This is also why I recommend trying to make use of the temp probes to create a comparable sensor value for the case fans that will not be affected by sudden loading/unloading.