Dimension 4600 - Northbridge 52 degree Celcius (126 F), normal?

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

Threaded View

There's no bios temperature monitoring on the Dell Dimension 4600. So
I've used a digital thermometer and made contact with the black
fanless heatsink on the motherboard's northbridge. I get 52 degree
Celcius (126 Fahrenheit). Is this normal temperature for a North
bridge? Should I install a fan on it? Should I install a better
Northbridge cooler?

Re: Dimension 4600 - Northbridge 52 degree Celcius (126 F), normal?

RakperBanengen@yahoo.com wrote:
Quoted text here. Click to load it

You're measuring the heatsink and not the casing of the IC.
The casing is likely hotter than that.

The current generation of organic packaged Northbridges are
good for about 99C case temperature. You can find the
chipset on the Intel site, find the thermal design document,
and get a Tcase max from there.

In a previous generation, where ceramic packages with glass frit
seals were used, chips could take about 135C. The temperature
has dropped, with the move to cheaper organic based packaging.
It is likely the packaging is degrading at that temperature,
rather than the silicon being in danger.

For info on whether your SuperI/O has a hardware monitoring
interface, you could check the list here, and look for
the SMSC chip on one corner of the board. (Alternately,
you could download Speedfan for Windows, from almico.com
and see if it detects thermal sensors.)


This is a picture of a motherboard for the 4600 from Ebay, and
the SuperI/O appears to be the chip in the lower right corner.
This is how I guessed the chip involved is from SMSC.


You could perhaps fit a 40mm fan to the top of the Northbridge
if you wanted. Sometimes the heatsinks are designed, such that
the four screws that fit in the fan holes, are an interference
fit between the fins. But be careful, because as you tighten
up the metal screws, they bite tiny bits of aluminum filings
from the black heatsink. Aluminum shavings could short out
closely spaced conductors on the motherboard.

Replacing the heatsink would be another alternative, but the
options available to work with the clip on that heatsink are
limited. I was thinking something along the lines of a
Swiftech cooler, but the Swiftech uses screws. Fitting a
different passive cooler isn't likely to help much.


I don't think the chip is in danger, but if it concerns
you, then fitting a fan might be arranged. On some
motherboards, the design intent is that side spill
air from the output of the CPU cooler, cools the
Northbridge. But with a Dell product, they're likely
to use a shroud for CPU cooling, which means the CPU fan
won't be cooling other stuff on the motherboard.

The noise from the fan may bother you. A 40mm could run
at 6000RPM. You could try a larger fan and an
adapter, but then you have to figure out how to
safely hold it to the heatsink, without mechanically
damaging something. This product is just to illustrate
how you'd fit a 60mm fan to a 40mm application.



Re: Dimension 4600 - Northbridge 52 degree Celcius (126 F), normal?

Quoted text here. Click to load it

Wow! That's a very nice answer. Thanks Paul!

I've tried a 40mm fan on the heatsink. It helped put the temperature
down to 35 degrees celsius. It's just that the screws are (long enough
but) two small to get a grip in the metal. How about Silicone II glue
from GE? Peelable, heat resistant, sounds good?


Re: Dimension 4600 - Northbridge 52 degree Celcius (126 F), normal?

RakperBanengen@yahoo.com wrote:
Quoted text here. Click to load it

You'd have to wait for it to cure fully. The MSDS suggests
GE280 gives off some byproducts while it cures. It used to
be that silicone seal gave off a vinegar smell, but this
suggests otherwise. I don't know if I could wait long enough
for a product like this to become odorless.


Is there any chance of retaining the fan by other means ? I've used
nylon ties for some fan applications, but the usual problem inside
the computer, is there is nothing suitable to grip to. The computer
I'm typing on, has one fan suspended via two nylon ties. You feed the
nylon tie through two screw holes, to give good positional control.


I've actually fitted a 40mm fan, to a Northbridge, for the same
reasons as you. I used screws and they happened to fit pretty
well. The Northbridge I was modifying, had a heatsink surface
temperature of 75C (and at that point, I turned off the computer,
as the temperature was still climbing). Once the 40mm fan was added,
the surface temperature dropped to 37C. The problem with that
computer, was there was zero case ventilation - it was an
"all-in-one" style PC, where the motherboard is mounted on the
back of the LCD panel.


Re: Dimension 4600 - Northbridge 52 degree Celcius (126 F), normal?

On Wed, 28 Jan 2009 17:35:43 -0800 (PST),
RakperBanengen@yahoo.com wrote:

Quoted text here. Click to load it

Is the system under warranty still?  If not, something that
more permanently alters it may work better.

Two ways I commonly attach fans to difficult parts are to
either drill a small hole in the heatsink tines on the four
corners, then slip a piece of ~ 18 ga. copper wire through
the holes to hold down the fan, or if the heatsink is
reasonably flat on top and the tines are spaced wide enough,
you can take common brass, case motherboard standoff studs
and epoxy them inbetween the tines.  Generally those are
6-32 threaded (less often 4-40), a size that makes it easy
to find screws of a suitable length at any good hardware

There are more elaborate methods like making your own
mounting bracket and screwing it onto the tines or base,
"sometimes" it's possible to use nylon wire ties but it
seems more difficult on some small chipset heatsinks, or of
course replacing the entire heatsink, preferably with one
using a standard full-framed low RPM fan that can be
replaced easily if necessary, as the typical aftermarket
heatsinks for chipsets have short lived and loud fans

Something else you might try is taking the heatsink off,
thoroughly cleaning off the thermal interface material, and
applying a fresh thin coat of a quality synthetic heatsink
grease.  However, with it getting down to 35C with the fan,
this step seems unnecessary if you add a fan.

Re: Dimension 4600 - Northbridge 52 degree Celcius (126 F), normal?

On Jan 28, 9:35=A0pm, RakperBanen...@yahoo.com wrote:
Quoted text here. Click to load it

Wow thanks Paul and kony for the great tips! I like the "drill holes
in the heatsink and use some copper wire to tie the fan on it" idea. I
went with the tie wraps solution, since it was the most easy way in my
case. There's two "hooks" to hold the heatsink to the motherboard.
I've used two tie wraps to fasten the fan (by the two diagonal
opposite holes) to those hooks. It worked wonderfully!

Thanks a lot guys for your help!

Site Timeline