CPU Fan question

[Rockhound-1]

I am upgrading my CPU from an AMD Duron 1ghz to an AMD Athlon XP 1600.

My question is:

Is my current fan good enough for an XP?

It was rated to cover most of everything that was out 6 months ago. I don't want to buy a fan if I am getting the same thing etc.

[chubtub]

That depends on what or current fan is? I would say that it should be fine, but I would look into it just in case. You should be able to look up the fan on a web site to see what it supports, assuming it is not a generic.

[jmichna]

Duron 1000mHz max heat output is 46.1 watts; the max heat output of a Palomino XP1600+ is 62.8 watts. If you talking about a TBred-A XP1600+, the max heat output is 52.5 watts.

These heat output values are all at default speed; data from AMD tech docs at amd.com website.

You're moving to a hotter cpu, whether you go Palomino or TBred-A. What are your temps like now? A new, higher capacity fan can be had for less than $10. Perhaps at least as important, what heatsink are you using?
jmichna

[Rockhound-1]

I wish I could remember the fan specs, but I would have to tear open case again. (I will later of course.)

My temps are really low....I think

One is 25 and the other is 36 at boot up of course, don't know where to get temps while under load.

I purchased the CPU fan at Frys and they said that the fan I bought was good for all AMDs including the XP line that I was looking at, but I never trust what they say completely.

[Bovon]

One thing to consider when mounting any fan on a cpu heatsink. If the fan being used is not a strong fan...(one that you don't want to get your fingers in accidently) then raise that fan up a little above the fins...(if that is the way it is setup to be mounted, right down on the fins) because if the fan is not a strong forcefull type, the back pressure from the fins will sometimes stall airflow, and little if any is cooling the fins off.

I have kinda tested this by using paper strips attached to the sides of a heatsink and a weak fan attached right down on the fins...the paper strips sometimes didn't move, or just a little. By raising the fan up about 1/4th inch above the fins, the paper strips would show some airflow thru the fins. I have also replaced the weak fan with a strong, high velocity fan like a black Delta...and there was a little difference I think, but much harder to see because the high powered Delta forced air thru.

It stands to reason that this is helpfull to airflow as well as taking stress off of the fan motor..its kind of like a boat motors propeller developing an air pocket around the blades and then cavatating in one spot until water fills in again.

To raise a fan up above the fins a little, go to the hardware store and buy 4 small rubber feedthru grommets. These are the things that we put in metal walls and electric equipment to pass wires thru. The screws to mount most fans are probably 6-32. Get a rubber grommet that has a small hole just a little larger than a 6-32 screw (or the size you are using) put a flat washer on the top and bottom of the grommet. You will probably need to buy the next longer screw as well.

[jmichna]

Bovon,
That is an excellent suggestion. That is exactly how you mount the fan to the ThermalRight AX-7 HS. They provide the grommets and longer screws. They don't, however, use washers... the rubber grommets are pretty high durometer ("stiff" or "hard"), but then again you shouldn't be cranking those screws in too tight anyway... just enough to deform the grommets a bit.

An added benefit to the rubber grommets is they reduce a bit of the noise you might experience by vibration when the fan housing is in direct contact with the HS.
jmichna