How important is the fan that covers the KT400 unit on a Gigabyte GA-7VAXP?
I asked a few months ago, when the fan died, and was told it wasn't a big
deal. I'm in the process of upgrading my video card and was told that fan
is VERY important. The mobo has been running ( with no problems? ) for 4-5
months without the fan. I'm sure that if it didn't need to be kept cool, it
wouldn't have a fan. I'm having a hard time finding, or even describing,
the fan near me.
I'm not sure the size, looks like a 30mm fan?
KT400 is not a very hot running northbridge. Many KT400
based boards did not have a fan on the NB. However, those
that did typically had a much smaller heatsink under that
fan, than would be used on a board with a passive (fanless)
NB cooler.
Since you've had it running OK for months, it would seem
you've already demonstrated that per your chassis cooling,
heatsink side-flow and/or ambient temp, environment, the NB
stays cool enough. Sometimes manufacturers add a fan for
marketing purposes more than anything else. Motherboard
reviews seem to come in waves, you'll see a bunch where
reviewers consider a fanned northbridge 'sink a "good"
thing, then another wave where they like passive/fanless
'sinks more. It would be nice to think they were
considering the NB's heat production but that doesn't seem
to the case.
Since it's already stable I'd leave it alone, or perhaps
remove the heatsink, clean off the original thermal
interface material and apply fresh thin coat of thermal
compound. Another option is buying an aftermarket, much
larger passive 'sink like a Zalman, Coolermaster, generic,
whatever, just with taller fins, more surface area.
http://www.svc.com/chipsetcoolers1.html
Your current/past fan wasn't like to be 30mm. That's quite
small for any computer fan outside of a notebook, or perhaps
in a drive bay cooler or built into old CD drives. The
typical box-frame type fans are 40mm. If it's a proprietary
fan, in a custom circular housing and/or with a mount on the
bottom to the heatsink then your choices are much more
limited.
From a couple pictures I saw of Gigabyte GA-7VAXP, it does
appear that yours came with a standard fan, for example:
http://www.tweakers.com.au/articles/motherboard/gigabyte_7vaxp/board.jpg
While at first glance it almost looks like a proprietary
type with bearing facing outward, on closer inspection it
looks to have a normal fan but a custom gigabyte grill on
top.
If you can find longer screws (and you have the extra
clearance from the CPU heatsink) you'd be better off with a
thicker fan. 10mm fans produce lower airflow per RPM
(louder per same cooling) and (comparing same quality fan)
they wear out faster even at same RPM, ignoring that the
lower RPM potential of a thicker fan might allow multiple
times longer operation. 40x15 or 40x20mm .08-.12 amp would
be a good target range, but the motherboard connector has
pin-spacing that isn't compatible with a typical 3-pin
motherboard plugged fan, if the picture above corresponds to
your board.
Offhand I don't know where to find a 40mm x ?? thick fan
with compatible motherboard connector already on it. 40mm
fans aren't hard to find though, you could splice the old
fan's connector leads to the new fan. You might measure the
old fan's housing to verify that it's 40mm diameter.
I'd get the passive 'sink, the blue Zalman @ SVC link above.
