120mm AcoustiFan Mods / High SB51G Board Temp

[Jools]

After reading Gordon Laing's column in PCW about replacing his ICE fan with an external 120mm, I thought I'd try it on my two SB51G's. I've just replaced my old Noiseblocker S4 80mm fan with an 80mm-120mm duct converter, and a 120mm AcoustiFan - bought from Kustom, naturally. ;)

Also, I've swapped the old modded PSU (the one that was still working) for one of the new SilentX PC40 250W models.

It did seem quieter to start with, before my noisy Sapphire fan spoiled the party, so it bodes well for my other SB51G box which just uses the onboard GFX.

The CPU temps do seem a bit cooler (38C idle, 55C SETI), but what I'm really having problems with is the board temp going through the roof. At idle, it's low 50's. Under SETI load it's mid 60's, which seems *way* too high.

I've tried to find the little blue bobs on the mobo where the temp sensors are, but couldn't find them.

Things are pretty neat inside, nothing is blocking anything. And it's dust free now.

Any ideas (that don't require cutting extra holes in the case) how I can cool the board temp anyone? TIA.

SB51G #1 (Games)
2.66GHz P4 Northwood
2x512MB Corsair TwinX CL2
Sapphire ATI 9600 128MB
Plextor PX-504A DVD+RW
Seagate Barracuda V 120GB
Seagate Barracuda IV 40GB
SilentX PC40 250W PSU
80-120mm duct converter
120mm external AcoustiFan
(replaces internal 80mm ICE fan)

SB51G #2 (Office)
2.4GHz Northwood
2x512MB Kingston CL2.5
Plextor PX-504A DVD+RW
Seagate B-V 120GB
Seagate B-IV 40GB
Stock 200W PSU (modded one went pop)
80mm Noiseblocker S3 ICE fan

[Jools]

I've just had another look at the PCW article. It shows the Acoustifan with the label facing outwards (towards the viewer).

I always thought the ICE fan was an exhaust, and the perforated holes down the side of the Shuttle case were inlets? I'm damn sure the old Sunon was blowing out, with the label facing inside the case. That's how I replaced the previous Noiseblocker S4 back in (which had been running that way for the past 8 months).

So I thought I'd switch it around just to see what would happen, and surprisingly it seems that blowing air IN to the Shuttle works best:

Exhaust (previous temps):

Idle: B-52 C-38 P-47 120GB-55 40GB-50
SETI: B-65 C-57 P-54 120GB-55 40GB-50
SpeedFan: 3%

Blowing In (current temps):

Idle: B-40 C-36 P-39 120GB-45 40GB-39
SETI: B-47 C-49 P-43 120GB-46 40GB-40
SpeedFan: 3%

It seems obvious which is the right way around [now], but is everybody else blowing air in?

[dejavu]

it all depends on the position of the fan relative to the heatpipes/heat vains(sp?) the air should always be blowing accross them not away from them, it just seem the air is moving faster as it leaves the fan

[Jools]

Well, blowing air in certainly works best for me by a large margin. I've been running SETI for hours, and all my temps are now in the 40's. A nice neat column of reassuring green ticks in SpeedFan, instead of licking flames...

If anyone else wants to try Gordon Laing's mod, I can now highly recommend it. My idle temps are all an average 4C cooler, and load temps all an average 10C cooler than before. The fan ticks over at 3% around 1100RPM. And it's quieter, too. Not silent, but peaceful enough for me. The new PSU definitely helps.

AcoustiFan 120mm:
http://www.kustompcs.co.uk/product.php?view=2571

120mm Duct Adapter
http://www.kustompcs.co.uk/product.php?view=3721

SilentX PC40 250W PSU
http://www.kustompcs.co.uk/product.php?view=1761

[MrStabby]

with regards to the PCW article, what issue and what page please! Can't find it to save my life!

[Jools]

April issue, page 174, Hands on Hardware

I've had my SilentX's in for over a week now, and I'm not quite so sure they were a good investment. The low thrumming is better, but it's been replaced with the whine other people have reported. Sometimes it cuts through me, like the old test card.

Maybe we'd be better off waiting to see if the proposed higher-wattage external PSU from Shuttle materialises...

Also, a warning about SpeedFan: I have a Belkin KVM switch, where you use <Scroll-Lock><Arrow> to switch between PC's. It's a great little device, but I've noticed if you've got an open window with an input box cursor blinking at you, the contents can sometimes be wiped out.

This happened when I left SpeedFan open and switched to the other Shuttle. I noticed a strange smell after 10m or so, and switched back to find my CPU temp was 80C, and my board temp was similarly sky high. All because the "3%" setting in the Fan3 input box had been blanked, turning the fan off.

Fortunately, after switching it off immediately and letting it cool down for 30m, everything was fine when I switched it back on.

Now, I realise that this was entirely my fault. Nothing wrong with SpeedFan. But it's something to watch out for unless you want to experience your own China Syndrome...