Best fan with SLK-800

SungHyun7 · Post by **SungHyun7** » Sat Nov 09, 2002 8:34 pm

Hey guys!

what's the best fan to use with SLK-800?

I have P3 1ghz running at 133mhz.

Quietness is the utmost priority over performance.

Actually, I wanted to clear out something. Is bigger fan rotating slower quieter than smaller fan rotating faster?

If so, I was thinking of getting couple of those 120mm fans (one for SLk-800 and another for intake).

let me know what you guys think!

quokked · Post by **quokked** » Sat Nov 09, 2002 10:15 pm

probably a Panaflow FBA0812L1A (have I got the number right guys?) the low speed panaflow........
- Bigger fan rotating slower is quieter cause less RPMs = less air turblence

have fun welcome to the world of quiet computing

Post by **MikeC** » Sat Nov 09, 2002 10:40 pm

Is bigger fan rotating slower quieter than smaller fan rotating faster?

I don't believe you can generalize; the noise/airflow/cooling is specific to the components & situation. In yours a Panalfo even at 5V will probably work OK. And it will be silent.

SungHyun7 · Post by **SungHyun7** » Sun Nov 10, 2002 6:40 am

heymike,

what do you suggest? i think my cpu (p3 1ghz w/ 133mhz bus) will dissipate about 50w. which fan should i put on top of the heatsink? one in particular? dang... these fans are pretty expensive... any good sites where you get them?

thanks alot mike. i love your work!

Gxcad · Post by **Gxcad** » Thu Nov 21, 2002 11:17 pm

I must jump in. Bigger fans are LOUDER at the same RPM. For example, the famous black label 60mm delta (38cfm) was about 6800rpm and 48.5db. The 80mm 68cfm I believe is 4700rpm and around 48.5db as well (approximate off the top of my head guesses). As you can see, the rated noise is the same yet the bigger fan rotates slower. Do not confuse bigger fans = more cfm for the same noise (true) with bigger fans = quieter because they spin slower. Bigger fans are louder per spin, but create more cfm per db. So in actuality, bigger fans are louder per rpm, and therefore harder to silence as much as smaller fans.

There may be flaws in my argument but I believe most of what I said to make sense. Please comment if you think otherwise.

-Ken

P.S. To answer the question, since you said quietness is the most important aspect, I would go with a panaflo 80mmL1A @5v over your slk-800. Any similar easy to find fan will do as well (silencer, stealth, papst, ect.)

quokked · Post by **quokked** » Fri Nov 22, 2002 1:03 am

I'd agree that some of the bigger fans are louder at the same RPM Ken but I think there's a optimal fan size for the best balance of noise and the size of the blades
but bigger fans you get to spin slower if they have good bearings on them to the point where they pump out a lot of air and VERY low RPMs.......
Personally I think 80MM is the best size for the fans for a balance between the two.... 60MM is too whiny and 92MM is too loud....

Renod · Post by **Renod** » Sun Nov 24, 2002 4:51 pm

[quote="Gxcad"]I must jump in. Bigger fans are LOUDER at the same RPM. For example, the famous black label 60mm delta (38cfm) was about 6800rpm and 48.5db. The 80mm 68cfm I believe is 4700rpm and around 48.5db as well (approximate off the top of my head guesses). As you can see, the rated noise is the same yet the bigger fan rotates slower. Do not confuse bigger fans = more cfm for the same noise (true) with bigger fans = quieter because they spin slower. Bigger fans are louder per spin, but create more cfm per db. So in actuality, bigger fans are louder per rpm, and therefore harder to silence as much as smaller fans.

[quote]

Actually there are several factors that contribute to the noise of a fan. What makes fan noise unacceptable is a combination of pitch and volume. Much of the noise is created by the air hitting obstructions in the flow path, by imperfections in the blades, and by the tips of the blades themselves. Larger fans create sound that is lower in pitch by virture of the longer path the air takes through the blades. Larger fans have a smaller % of restriction caused by the fan case and the supports which means lower noise per rpm from that cause. Your general statement that "bigger fans are louder per spin" is not necessarily true. They are much easier to silence than smaller fans to product the same work (CFM) with more pressure through the system. If you would like to learn more about the general subject, read http://www.amdmb.com/print-article.php?ArticleID=132.