Nekochan Net

I've been wondering for months how to get rid of that wooshing sound my Octane2 is producing. A fan replacement was done already with the frontplane XBOW and disk cardcage fans, but the one making the worst noise was the PSU fan. Reliability-wise, SGI din't make a bad descision in choosing fan suppliers, the Panaflos are known for having an excellent MTBF and by using them they could probably forget issues regarding cooling.
However, the noise is unrealistic when trying to use it as a somewhat modern piece of desktop computing platform. Therefore a fan replacement was put into motion.

Ripping out the innards of the Lucent PSU was a pain, but the newer Cherokees are excellent to open and things are packed at logical places. (Apart from 961428pcs of screws)

I must point out - before trying to replace the fan, be aware that there are potentially hazardous live electricity left in capacitors and other stuff in the PSU. Do not do this if you don't know what you're doing!

My replacement for the Panaflo FBA12G12U fan was the Kaze-Jyuni SY1225SL12H (Slip Stream 120) fan, which are known for their excellent flowratio compared to their size, speed and sound. The swap was dead-simple, I didn't even need to cut & solder wires! All there is to it is to cut the screws about 10-15mm (because of the thinner fan size) and switch the yellow+red cable poles and just stick it into place.
The fan grille was put into the recycle bin - just make sure there are no cables from the outside blocking the fins.

I tell you - the system is whisper quiet!

The airflow dropped from 115CFM to 88CFM, but the noise went down from 45dBa to only 33dBa. Considering the mild spec of this system (nothing else than a R12k-300 and V6-gfx), it won't even touch the maximum performance needed from the old fan. I've been running SETI@Home for a couple of days now and everything is the same as before. The air coming out of the PSU is still as gently warm as before and no component seems hotter than before. I'd bet even a dual-CPU or V12 ain't pushing things.

_________________

I wonder if an IR thermometer might find some variations in heatsink temps. Regarding sound, run the machine every day for a year and you wont hear it anymore. It might be from becoming deaf, but who really knows.

Hmm, I'm thinking of replacing the PSU fan in my R12k 400 O2...Just did a drive swap and now have a quiet 10k Maxtor Atlas IV in there...Machine is on the desk next to me! Hardly any heat coming out at the moment....

Only question is how low can I go with my CFM airflow rate on the O2?

I'm thinking a Zalman ZM-F1 will do either 20 or 36 cfm (20/34 dBA), a Thermaltake 8025a will do almost 37cfm at 30dBA...

Also, anybody replaced the CPU fan with something more silent?

Jacques.

_________________
No SGI box currently...Snif!

do you maybe know, can i use this one with Indigo2 Impact PSU ? the size seems the same * 120 mm, but i`m unshure about the airflow, and congrats for the hack.

cheers

_________________

-----------------

You always, always, ALWAYS must keep an eye out on the CFM rating on the existing fan and what you're replacing it with. If you feel that your system is well blow max-spec, maybe you can push things to go further down on CFM in the hunt for lesser noise.

But, there's always a risk involving this and one have to remember that SGI (and others) choose fans for two simple reasons:
- Reliability
- Performance

The first priority would probably be reliability. Have you ever experienced a bad fan on a SGI (or other workstation class) system, operating in a controlled enviroment? I have, but never near PeeCees extent. They choose Panaflo for their excellent reputation in low MTBF.

So, they could very well be happy with the performing fans in, say, the Octane and just keep it that way. The system itself kept the heat out of the system and kept the support department low on bad components in return. However, in todays computing we're not satisfied with this so we get picky about it.
By running a less CFM rating on the fans (to keep the noise down), you have to be sure not to stretch your surronding operating enviroment as you could with the stock fans. Keeping the system running at cooler evenings or even in the wintertime make up for the lesser performance and could help the components running cooler.

The PeeCees pushed by TCO and other work enviromental rules out there are aiming at quieter computing, pushing the development for better heat exchangers and lower heat output chips. This wasn't an issue back in the glory days...

Your Indigo2 fan can very well be replaced with a SlipStream 120 (in whatever RPM-rating you require), but please compare the stock fans modelnumber (and therefore CFM rating) to keep it within limits.

_________________

Also check this thread, basically replacing the Panaflo with the same model but lower CFM, with TRAM temperature data.

I also saw some 'Super Kaze' fans a couple of days back that were 38mm thick (but fast rotation, not much different than the fast Panaflo) but there may be 'quieter' versions in that series.

_________________
<> x2+ x3 x2 x2+ x2 x3 x2+

Once you step up to the big iron, you learn all about physics, electrical standards, and first aid - usually all in the same day

How about this baby in the Octane PSU??? http://www.silenx.com/ixtremaprofans.asp?sku=ixp-76-18 Super quiet!

-Jacques.

_________________
No SGI box currently...Snif!

For some reason I keep thinking that I read somewhere that those fans didn't deal with static pressure very well, they worked best in open apetures (like the back of a PC case) than enclosed applications. The 38mm thick one's might be better.

The Panaflo's have one other advantage - you can reuse your power cable as it plugs into a little connector on the hub of the fan, as the existing fan is already a Panaflo (need to check a Cherokee, but pretty sure). So no soldering and no cable hacking required. Truly drop in.

_________________
<> x2+ x3 x2 x2+ x2 x3 x2+

Once you step up to the big iron, you learn all about physics, electrical standards, and first aid - usually all in the same day

The Iextrema fans are performing, but as pointed out, they can be a little hard to get enough air pressure through them and reports on other forums claim that they don't perform as well as the tech specs. Add to that - they are expensive too.

_________________

Yeah, just noticed $25 a pop!

I may go for the same fan (Slipstream 120) as you got ramq, but would it be enough for a dual 400 and V12...? (Just traded my O2 for a V12...O2 was just too slow for Maya) There is also the 120x120x38mm Kaze Ultra fan, but it has a marginally reduced CFM of 87.63 vs the 88.1 of the 25mm fan.

I haven't done anything to the frontplane or drive bay fans yet, but think I'll replace the drivebay fan as well...Anybody know what fan is in the drivebay? I've read the frontplane fan can be a bit difficult...

_________________
No SGI box currently...Snif!

Be aware that there are several versions of the Slipstream 120 with different RPM-ratings. You might want the higher rated version if you're unsure of the CFM ratio...

_________________

Any time you can ditch a grille you're going to reduce noise. Grilles cause a lot of turbulance. Turbulence = noise.

Success!!!

Thanks to ramq, I've replaced my Octane2's PSU fan with a Scythe Kaze Jyuni 1900RPM Slip Stream 120 fan (slightly faster than ramq's) that produces 110 cfm at 37dBA...The PSU is easily taken apart, with all the screws out the cover just slides off. (Be VERY careful not to touch any of the goodies on the inside!)

The drivebay fan was replaced by a Zalman ZM-F2 quiet fan running with the provided fan voltage regulator (12v-7v). It pushes about 37 cfm at 20dBA.

Neither fan needed any wire cutting, they just dropped in. As ramq noted, the Slipstreams need to have their yellow and red poles switched on the power supply end. ( Black [-] / Yellow [rpm] / Red [+12v] )

Overall the machine powers up fine and gets to the point where it complains about lack of video card. I've not got a video card in as I'm waiting for a V12. (That's the reason I went for the 1900rpm Kaze Jyuni, also, I didn't want to starve the machine while rendering Maya images) I've also left off the PSU grille...

But best of all, SILENCE compared to what it was! The machine is under my table and the drives sound really loud now. Instead of the usual hairdryer effect there is a gentle warm background woosh...VERY NICE!

I suppose if you're running a single proc system with a V6 or something less powerful then you could reduce to what ramq has in his.

I'll keep monitoring.

Oh, and one other thing...DON'T stint on the drivebay fan when it comes to flowrate, it provides quite a bit of cool air to the top of the graphics card where the heat sink is. I guess it's used to circulate air from the top of the machine to the power supply area.

Jacques.

BTW: I bought my fans at http://www.quietpc.com, very fast delivery!

_________________
No SGI box currently...Snif!

Oops, I posted to the Fastfan thread but meant to post here. So, copy/paste...

Since I will be opening my surplus store again soon, I am getting pricelists, etc. for SilenX iXtrema fans and Noctua fans. The specs look great for both lines and both offer the longevity of fluid bearings in their fans. If I can get them cheap enough wholesale I may be able to do a special Neko member sale.

RE: Octane fans, I'd think a thermistor fan w/ 80-100 CFM may do pretty well. Leave fastfan set to high and let the thermistor in the fan run the throttle. SilenX 120mm x 25mm thermistor fan is rated at 24-72 CFM, 6-14 dBA @ 600-1400 rpm.
If that's a little too close to the edge for ya, they also have a fixed speed 120 x 38mm fan rated at 90 CFM, 18 dBA @ 1400 rpm which I would think would work as a direct replacement for the PanaFlos.

_________________
Office: Evo W8k; 2xXeonDP@2GHz, U320-15k RAID, 2x 23" LCDs, SpaceBall 5k | G5 Quad 2.5 | G4/800
R12/400 V6 [ShoeBox->U160, USB/1394, 1Gb FC] SpaceBall 4k | R12/400 V6 <(WAS) X-Wife's> | Dual R12/300 V6
Toshiba 17" Core2@2GHz | Fujitsu 5120 Tablet PC | MacBook Pro 17 | P'Book G4/550
Closet: R12/400 MXE R10 SI R10 Xtrm XZ24 R10/175 P.Iris Iris File Elan! R44/?(2 B Hack'd)

has anybody bothered about the third fan, the one on the xbow? experience tells that those small fans rotate with the highest speeds and therefore omit the most noise, so should not be overlooked

on my xbow 1.3 it's a SHICOH ICFAN 0610-12L DC12V 0.08A 1CUC. i googled but can't find any data about it. does anybody have some information on that one?
i already bought a fan of the same size with external speed adjust but that might have been a little too hastily. looking forward to installing the old fan again with a thermometer in place, measuring heat, installing the new fan, measuring heat, adjusting speed, disassembling again to free the thermometer. omg...

P.S.: just found some information on the little xbow fan in another thread

_________________
goodOldBoy rulezOkay willHaveToGo wouldBeNice