Heatsink dual fan configuration

[MPC7500]

Hello,

I would like to know, if the dual fan configuration works in the meantime on the Blackbird? Was there any progress or any kind of update?

[ClassicHasClass]

What do you mean, "dual fan configuration"? My Blackbird has four fans, two on each fan header (CPU and case) using a splitter. I can observe both pairs operating independently.

Or are you referring to some sort of dual HSF assembly?

[MPC7500]

Yes, CPU dual fan config. On the Talos-II it works, on the Blackbird not:
https://wiki.raptorcs.com/wiki/Dual_92mm_fan_CPU

On my 2U HS the CPU is running a little bit hot.

[mx08]

I think that depends on the fans you are using in combination with the firmware.

AFAIK the reason the dual fan mod using two Noctua NF-A9 PWM fans doesn't work on the Blackbird is that it uses a newer firmware than the Talos II. See also the point:

note, on firmware 04-16-2019 dual-fan mod no longer works reliably, as new less agressive profiles spin down fans below minimum speed and opembmc print a lot of warnings about CPU0 fan being inoperational. fan still spins, but fails every 10 seconds, spins up and fails again endlessly. refer to Fan Tuning page for a fix.

from https://wiki.raptorcs.com/wiki/Dual_92mm_fan_CPU

As explained in the Fan Tuning page, you can adjust the parameters in OpenBMC to make it work.

I suppose you could also use !BMC (https://git.anastas.io/dormito/br-blackbird-external) in place of OpenBMC, where you can configure the fan settings more easily (AFAIK you need to recompile it to update fan the settings, but compilation takes less time and the fan daemon infrastructure is simpler).

[MPC7500]

Cool, thanks. I didn't read the thing about the fix. I will give bangBMC also a try. It's quite possible that I'll get back to you, then.

[MPC7500]

@mx08 or @ shawnanastasio:
In the next few days would like to update to bangBMC. Is the procedure identical to Updating the BMC firmware?
Or how do I proceed?

And is there a comparison table (features/ pros and cons) somewhere between OpenBMC and bangBMC?

[xilinder]

On my 2U HS the CPU is running a little bit hot.

Could you please post a picture of your 2U heat sink setup?
Never seen one.

[shawnanastasio]

@mx08 or @ shawnanastasio:
In the next few days would like to update to bangBMC. Is the procedure identical to Updating the BMC firmware?
Or how do I proceed?

And is there a comparison table (features/ pros and cons) somewhere between OpenBMC and bangBMC?

bangBMC is currently in pretty early stages and I wouldn't really recommend it unless you have flashing hardware and BMC serial access to recover in case something goes wrong.
As far as a comparison table, I don't think such a thing exists, but I should talk to bangBMC's creator (dormito on IRC) about creating one.

The TL;DR is that it's a super simple distribution that just contains the bare minimum for booting the P9 cores and nothing else. (no systemd, no dbus, no web servers, no python, no C++ runtime)
This makes it well suited for desktop machines where you don't necessarily need/want all the features oBMC provides and would prefer a minimal (and much faster!) replacement.

The fan daemon I wrote is pretty bare-bones and should be much easier to configure than the oBMC one.
The current algorithm works by just reading the current maximum temperature per-zone and looking up a corresponding fan speed in a table, so changing it should be pretty straightforward:

https://git.anastas.io/shawnanastasio/op-fan-daemon/src/branch/master/include/curve.h

Eventually I'll add config file support and a fancier PID-based control algorithm. Once this is done, Raptor has expressed interest in potentially shipping it along with bangBMC as an option for some of their machines. 

[MPC7500]

Hi,

I thought shawnanastasio / dormito are the same person. Sorry about that.

In the next couple days I will do some small modifications on my setup. Also I will put in an ASSMANN AK-610300-003-E. Then I have a serial connection. What just comes to my mind, wouldn't it be better to buy another chip and program bangBMC on it? Then you can easily change the chips if needed. I have a Bus Pirate, too.

Could you please post a picture of your 2U heat sink setup?
Never seen one.

At the end, it's a 3U HSF, little bit smaller and without fan.

[MPC7500]

@xilinder: Pictures

Not beautiful, but rare (picture quality)

Edit: Here is by far a better picture.

[MauryG5]

Sorry guys, taking up the second fan speech managed by the Blackbird, I didn't understand exactly how to regulate the speed. I have a fan installed in the case which acts as an extractor fan to blow out the hot air produced by the CPU and GPU. Except that the speed of both fans, that of the CPU and the external one connected to the FAN2 pin of the motherboard, are the same so that after loading the PetitBoot, these slow down to the minimum speed. I would like to set the second fan FAN2 at a higher speed so that it sucks all the heat produced inside better. Is there a way through BMC to adjust this speed? Thank you

[MPC7500]

You have three fan connectors on your Blackbird.
Fan1: CPU
Fan2: Rear
Fan3: Front

In total, I have installed six fans in my case.
You can't adjust the fan speed by yourself.

[MauryG5]

So you're telling me that it's not possible to independently adjust the fan speed. Does Fan 3 also have the same speed as Fan 1 and Fan 2? I need to have a faster fan for extracting hot air from the inside ...

[MPC7500]

Why do you need a faster fan? My fans often spin at the same speed (100RPM). Sometimes one spins faster (200 or 300RPM).
The fan speed is self-regulating. It is a PWM signal.

The fan curve when and how fast the fans are rotating can be adjusted. But for that you have to adjust the curve and then recompile the firmware.

[MauryG5]

I wanted it a little faster because after a few hours of use, especially when you make the system work more, it starts to warm up a little, it feels to the touch touching the case and therefore the low speed does not help to expel the whole well hot air. I therefore put a fan connected directly to the power supply and then at maximum speed and in doing so the air is expelled much better and the system remains fresh but it makes itself feel like a little noise. If I could adjust this fan I think it would have been better but since it cannot be done, I will try to find a quieter fan and always connect it directly without going through the motherboard, in this way I will always have a full expulsion of air.