[Knezzen]

Hi!

My Octane is LOUD (probably like everyone elses). Have anyone here put like Noctua fans or silent fans of any other brand inside their Octane?
Did it make much of a difference? How many fans are there inside the Octane and what are the dimensions?

My fans allways seem to run at full blast regardless of how much stuff I have running. Is this normal for the Octane? Does it not have thermal managed fans?

Sorry for the multitude of questions in this thread. Just a SGI and IRIX newbie trying to get by

[55cancri]

Yes, I replaced all the fans. The frontfan is a nasty one, mine made a high pitched noise. I drilled out the rivets of the fanmetalcage and screwed in a slightly larger one. The metalplate right in front of the fan makes the fan even louder.
The down side is, that these high voltage bolts protrude from the naked xbow board. A bit deadly ... but my flat is just 30 squere meters in size ... and this thing needs to be quiet ^^

(Hmm, picture attachment is not working)

[jan-jaap]

My fans allways seem to run at full blast regardless of how much stuff I have running. Is this normal for the Octane? Does it not have thermal managed fans?

There's no real thermal management. Nothing like the PWM regulated fans we're used to these days. The CPU itself doesn't even know about idle modes or frequency scaling so it always puts out the same amount of heat, whether it sits there idle or is under full load.

The Octane knows about "normal" and "fast fan" mode, though. If you have a card installed in XIO slot 'D' (that's the side where the graphics card is, bottom right corner when looking from the back side), the it will always engage "fastfan mode, which is infernal. I think it can engage fastfan mode also when the temperature crosses a certain threshold.

[vishnu]

I've never tried it because fastfan never kicks in on any of my SGIs, but doesn't setenv -p fastfan 0 turn fastfan off?

[Jacques]

Mine runs quiter than my R12k O2.

This is how I made my Octane quieter. 

When working in your PSU be careful of discharging caps etc. You can harm yourself / your machine / possibly even kill yourself from electrocution if you're not careful - You do this entirely at your own risk!! 

A) remove the metal front fan grille. The little xbow fan sucks in air across the sharp corners causing lots of hissing noise. To remove the grille remove the metal cover and drill the rivets out. Clean out metal bits before re-assembly.


Mind the big termination poles, they carry a lot of current!!!

B) change the drivebay fan to a Zalman F2 with inline resistor. I've found this fan pushes quite a lot of air and keeps my V8 gfx card cool. For MXE / MXI I'd suggest not running with the in line resistor. Contrary to popular belief, air is pushed over the drives from the drive bay fan and not sucked into the machine at this point. 

Remove the frontplane.



Zalman F2 92mm fan fitted to rear airbox





While you're there, apply insulation tape over the gap between the airbox and the scsi backplane pcb, stops some of the positive pressure from leaking out the edges. 

The below shows the perforations where the drive bay fan has to push air through into the XIO carrier area.



C) for cherokee psu, change fan to a Scythe Kaze 1800/1600rpm 120mm fan. You will need to cut two of the long screws to accommodate the shallower fan. I'd run 1800 rpm for MXI / MXE due to the additional heat generated, or get a Papst fan. On my single 400 I run a 1600rpm fan with very good results, the cpu only gets slightly warm to the touch.



This shows the Kaze fan installed without the wire grille.



Cut two of the bolts to accept the thinner fan casing and handle.



Remember to swap the yellow and red wire on the new fan connection. 





The drive bay fan supplies cool air, the psu extracts air via slots in the case at a lower level and also draws some air via the top vents....though I suspect more warm air rises naturally and escapes here than what gets drawn in...

I have loads of photos from an old nekochan post, I'll find them this evening. (Photos added)

[Jacques]

I've never tried it because fastfan never kicks in on any of my SGIs, but doesn't setenv -p fastfan 0 turn fastfan off?

Yes, but I believe only if you have no card in XIO slot D and no PCI card cage.

[gijoe77]

JacquesT, man that is awesome

[callahan]

Just a note, I think XIO slot D and C were mixed up above. At least on my system, fastfan only defaults on if XIO Slot C (which is the bottom right, farthest from the default ESI graphics locations) is filled.

[stormy]

Just FYI for anyone else drilling out the rivets to remove the cage, this wasn't mentioned in the original post but after removal of the rivets you will need to remove the main board from the case, unscrew the motherboard from the chassis and then the cage pulls through the inside out the back.

[Jacques]

For sure, drilling should always happen with all boards out. I took them out when I had the whole Octane in pieces.