Passive cooling integrated Video & SB - Trying fanless

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Jadukey
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Joined: Wed Oct 28, 2009 5:30 pm
Location: USA

Passive cooling integrated Video & SB - Trying fanless

Post by Jadukey » Wed Oct 28, 2009 5:58 pm

Would anyone recommend a passive northbridge cooler for a gigabyte motherboard with integrated video (GA-MA785GM-US2H)?

I've assembled a system and want to be able to operate fanless while CPU is idle/under light duty email/web (I have fans installed that I will activate manually if necessary to watch fullscreen video or gaming.). The problem I find is that the AMD 785G northbridge and southbridge seem to get too hot. Would anyone recommend a passive cooler for northbridge ? --I'm having trouble finding an appropriate heatsink because the northbridge heat sink looks pretty big compared to some of the aftermarket coolers I've looked up via newegg.

The northbridge currently heats up to ~45 - 50C without a fan, is there a "safe" temperature range to aim for?

PC details:
Athlon II 250 Regor
GA-MA785GM-US2H microATX
Scythe Ninja CPU cooler
Intel SSD
X650 PSU
ThermalTake ElementS case

picture showing cooldown temps after I reactivated fans
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picture showing NB (with blue gigabyte logo)
Image

JamieG
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Post by JamieG » Wed Oct 28, 2009 7:21 pm

Depending on how far apart the two mounting holes are, you might be able to bend one of the mounting clips for a Thermalright HR-05 to fit.

I did this with my Gigabyte 780G motherboard.

bonestonne
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Post by bonestonne » Wed Oct 28, 2009 7:31 pm

I second the HR-05. I have one on my P45, although I don't have integrated graphics. I also tried using one to cool a VIA C7-D, but that didn't quite work out, and I'd have to get a second one and try again sometime maybe...but where i am no, there's no point.

with or without a fan, the HR-05 will be a huge drop in temps, it only needs a little bit of airflow to cool down a lot.

porkchop
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Post by porkchop » Wed Oct 28, 2009 8:16 pm

first of all, are you guessing which temp is which? cause i have the same mobo and gigabyte easytune is telling me that temp1 is SYS and temp2 is CPU.
moving on, 50C is fine for a chipset- i'm sure they can safely run at even higher temps, spcr has tested the same chipset which hit 70C -my personal safe temp is 60C.

i would suggest that before a new heatsink, try changing the thermal gunk first (if you haven't already) -i've done it myself and i can tell you that the stock stuff is pretty crappy, though honestly i don't know how much good it will do.
you can also remove the gigabyte logo, its stuck on with foamy double sided tape- not good for anything.

here are my temps:
10 min. into orthos
temp1 34C | temp2 34C | temp3 36C | core 28C
idle temps
temp1 33C | temp2 27C | temp3 30C | core 22C
except i'm running an undervolted sempron 140(800mhz 0.776v - 2.7ghz 1.040v), a xigmatek apache top down cooler(92mm 1150rpm, too fast really) and also open case.

Jadukey
Posts: 20
Joined: Wed Oct 28, 2009 5:30 pm
Location: USA

Post by Jadukey » Wed Oct 28, 2009 9:26 pm

thermalright HR-05 looks like the best option, the discontinued Noctua NC-U6 looks to have inferior mounting and no other brands have anything comparable that i could find. I saw there's a "SLI" Thermalright HR-05 variant that joggles the fins so that a long video card can still fit over the chipset; this might be useful for the SB chip, if i decide to replace it.

porkchop, you're right I was guessing that the hotter of the temp1/temp2/temp3/Core temperatures were the NB/SB readings. where is the "SYS" on the motherboard? what do you think the readings for temp3 and core represent? I could only feel the heat sinks of the NB/SB which were both hot to the touch, compared to the ninja (cpu) which was cool to mildly warm. I am doubtful about how well the NB/SB will do without forced airflow. Natural convection is pretty crappy and the NB heatsink's little stubby fins +covered fins aren't oriented well (IMO) for my tower case.

I'm pretty much sold on replacing the NB, but I'll go ahead and remove that insulating foam logo and reseat the NB/SB heatsinks to see if it makes any difference.

porkchop
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Post by porkchop » Wed Oct 28, 2009 11:39 pm

i missed that you were running semi passive, in which case reseating the heatsinks isn't going to do much (unless the stock stuff is completely useless), all it'll do is make the heatsinks reach their stable temps quicker. in a passive environment, a bigger hs can only be as effective as convection.
regardless, if you can make a hr05 fit, then show me how! cause those mounting holes are further apart than usual.

this is what i think of the temps:
temp1 -some random sensor on the mb, doesn't move much when the cpu is loaded, too cool to be the sb or nb. i think.
temp2 -gigabyte says cpu, so i think its the mobo sensor for the cpu. common before they started getting their own sensors.
temp3 -vrms, because it rised with cpu load. i don't think the sb or nb would get hotter when the cpu is stressed, but it makes sense than the vrms would.
core -cpus own temp reading, should be more accurate than the mobos cpu temp reading.

JamieG
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Location: Melbourne, Australia

Post by JamieG » Thu Oct 29, 2009 3:02 pm

porkchop wrote:regardless, if you can make a hr05 fit, then show me how! cause those mounting holes are further apart than usual.
You can bend one of the mounting clips to make it work. I did it with my HR-05 IFX - off the top of my head my Gigabyte 780G's 2 x mounting holes were approx 84mm apart.

I managed to make it fit in my HTPC - it was a little bit dodgy though. I might not be too comfortable with bending the HR-05 IFX's mounting clip if the motherboard is being mounted in a tower case though. The tension wasn't perfect as a result of the bending. YMMV, anyway.

Jadukey
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Joined: Wed Oct 28, 2009 5:30 pm
Location: USA

Post by Jadukey » Sat Nov 07, 2009 3:11 pm

Thanks for your comments, here's what I ended up doing:

I first tried removing the gigabyte logo (NB) and replacing the thermal tape (that comes stock on the board's NB/SB heatsinks) with good thermal paste. Only the tape on the NB had apparently gotten hot enough to melt. Afterwards, the NB heatsink was still too hot to touch (maybe even seemed hotter than before) with the PC in idle.
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I bought a HR-05 IFX and also an HR-05 IFX-SLI. For the NB mount, I tried straightening out the longest HR-05 bracket (comes bent), but ended up accidentally breaking off the end. I broke off the other end, too, and used those two end-pieces to extend one of the other short brackets by fastening the three pieces together with some MB mounting nuts and screws. This kept the bracket's dimple in the center. The resulting mount seems fairly stable, although the heatsink can be made to twist a little about the mounting bracket's dimple point. The HR-05 is dwarfed by my ninja cooler, but seems much cooler than the stock heatsink.
Image

I couldnt find a good location to mount the HR05 IFX-SLI to the SB chip, the heatpipes were too close and/or interfering with the capacitors and USB pins on the motherboard. One end of the retaining bracked also interferes with the IDE cable slot, but the bracked could be trimmed to make room. The stock heatsink seems to get too hot for its own good, but I'll leave it alone for now.

Temps as I'm writing this (fanless--all fans off) are:
Temp1 39,
Temp2 39,
Temp3, 42,
Core 30

JamieG
Posts: 822
Joined: Fri Dec 26, 2008 10:31 pm
Location: Melbourne, Australia

Post by JamieG » Sat Nov 07, 2009 5:02 pm

Nice!

For the SB, check out the smaller Zalman ZM-NB47J or Zalman ZM-NBF47.

I have the NB47J on the SB of my Gigabyte G31-based mobo and it does a lot better temperature-wise than the stock heatsink. The adjustable mounting clips on the NB47J means that you can fit it on a SB as well, despite Zalman advertising it as a NB cooler.

From your mobo pic, it looks like the NB47J would be your best choice as well.

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