Hot Smart Array P440ar RAID controller - Can I repaste it?

[scotrod]

Hey!

I have a homelab HPE ML350 GEN9 server that is fairly quiet and cool during the winter, but in summer time one of the fans spins up a lot, because of the RAID controller (Smart Array P440ar) that is running around ~70° Celsuis while the server is idle/not doing any heavy tasks in particular.

I installed a 40mm noctua 5v fan (used one of the USBs on the motherboard), but I managed to lower the temps with just 10 degrees, which was a lot, but still not enough for such a hot component.

As far as I know, this RAID has never been pulled out of the motherboard. I'm pretty new when it comes to server hardware, and I have no idea if the passive cooler can be repasted.

Can someone confirm if I can repaste it? I'd like to get a few opinions here, before going and disassembling it.

Thanks!

 

[Chriggel]

Of course you can, you can repaste basically almost anything. I've handled a lot of P440ar when this was the latest hardware generation, but mostly due to firmware issues and sudden deaths and they were replaced by HP, so I've never disassembled one. I'd say that it's likely that it doesn't use paste and just a thermal pad instead. It's not the first time that a thermal pad and heatsink combination would provide an ineffective fit. I'd say that you'd have a decent chance of improving the temperatures by checking the pad or repasting it and checking the fit of the heatsink.

But with that said, 70°C isn't THAT high and if the improvements are good enough so that the fan doesn't spin up that much remains a bit of a gamble. I've only dealt with DL Gen9 servers, but I do remember that older ML had a fan setting for quiet operation. If it still exists, did you already enable it?

 

[scotrod]

I've only dealt with DL Gen9 servers, but I do remember that older ML had a fan setting for quiet operation. If it still exists, did you already enable it?

Unfortunately, I think not. Upon checking the bios, the first option I have is the "Optimal Cooling".

Stupid question: If the heatsink uses thermal pads, can I remove the pads and use just a thermal paste instead?

 

[Chriggel]

Stupid question: If the heatsink uses thermal pads, can I remove the pads and use just a thermal paste instead?

In theory, yes. But in practice, it depends on how thick the pad is and the resulting pressure of the heatsink. It might be too low with paste. You could layer the paste, if it's sticky and gooey enough, in such a way that it works. But that's really bad pratice, so, I'd suggest to not do that. You could also make a cutout in the center of the pad and use it as a spacer and fill the cutout with paste, but then again, too much paste insulates and the result might not be better than it was before.

Maybe it requires a modification of the heatsink or the mounting. Since there's no mounting hardware for it and unless you want to fabricate your own, we're probably looking at ghetto methods here, like fixing the heatsink with cable ties and adjust the pressure this way. I've seen it before, I've done it myself, but I really wouldn't recommend it if you don't know what you're doing or just want to learn unconventional things and can afford to kill that controller in the process.

 

[scotrod]

Thanks a bunch for the help!

If I understood correctly, your first suggestion might be the safest one for me (since I'm not experienced either server hardware nor doing ghetto mods) - just checking the thermal pads and eventually replacing them?

I think that the larger part of the cooler should be sitting on top of the "CPU" of the RAID with a thermal paste, while the lower part (on the right) should be sitting on a thermal pads, on top of the memory.

 

[Chriggel]

If I understood correctly, your first suggestion might be the safest one for me (since I'm not experienced either server hardware nor doing ghetto mods) - just checking the thermal pads and eventually replacing them?

Yes. Sometimes pads have a very weird fit and they just need to be reapplied to make good contact. Or replaced if they're old and crappy.

If there's paste on the chip, you know what to do. If it's a pad, the above applies, and while you're at it, you can check if you can paste it instead. Use your judgement, the springs will push the heatsink down and you have to decide whether it's enough pressure or not. There's usually not that much pressure with these spring mountings anyway, so don't expect a tight fit, like with CPUs.

And if there are pads on the memory, don't bother replacing them with paste, memory doesn't get that hot. Also, there's no mounting on the far end, so it's just adhesion that keep the heatsink in contact with the memory anyway.

To get the heatsink off, you will need pliers to squeeze the push pins on the bottom, so that you can pull them out at the top.