ThermalRight: 92mm or 80mm Fan?

hitman47 · Post by **hitman47** » Fri Feb 13, 2004 4:16 pm

I wanted to ask for some advice on the ThermalRight coolers such as the SLK-9xx and the SP-9x. I see that these coolers are generally longer then they are wider, such as length: 90mm, width: 59mm etc.
Thus, I'm not sure whether to purchase a 92mm or 80mm fan for the Thermalright cooler I am looking to purchase...

92mm:
Larger size, more CFM per RPM, therefore lower noise levels for the same CFM as an 80mm fan.
Furthermore, the 92mm fan overlaps the width of the coolers, providing some airflow over the motherboard. However, the 92mm fan has a larger dead spot, so it would appear that there is less air passing through the fins of the cooler (due to deadspot) and more over the motherboard (due to overlap) ?

80mm:
Smaller size, thus has to spin faster for the same CFM as an 92mm, thus louder for the same CFM.
However, the 80mm fan does not overlap the heatsink as much and has a smaller deadspot, so a greater proporton of air passes over the heatsink itself - perhaps therefore speed could be lowered due to more efficient cooling, to provide a quieter solution. However, the lack of overlap means the motherboard gets less cooling from the CPU fan.

To conclude, it would appear to me that both are virtually equal.
The 92mm is quieter at the same CFM and provides some motherboard coolng.
The 80mm is louder at the same CFM, but more air passes through the heatsink, so perhaps the speed of the fan could be reduced, reducing the noise.
I would appreciate any feedback to the question at hand; some experience with 92mm vs 80mm fans would be ideal.

Kind Regards

Edward Ng · Post by **Edward Ng** » Fri Feb 13, 2004 5:31 pm

Hello! I have tons of personal experience with the ThermalRight heatsinks. I've used an SLK-900A on a Socket-A platform and am currently using a pair of SP-94s on two Socket-478 platforms.

I personally recommend either 92mm fans or the YS Tech TMD Fans (approx. 70mm) for the SLK-900x heatsinks, and I only recommend 92mm fans for SP-9x. The much smaller dead spot on the TMD fan makes up for its smaller radius compared to 80mm fans, and the TMD fan has a much lower noise signature because of its design. 92mm fans, however, perform best overall, and you can't use TMD fans on the SP-9x models anyway; they only have two pairs of clips, and don't have the smaller set of inner notches to fit TMD fans.

If you can find a better 92mm fan (AcoustiProducts' AcoustiFan AF92CT is my recommendation), then definitely go with 92mm. Don't go with the 92mm Vantec Stalth Pro fan by all means, please. If you find the AcoustiFan AF92CT is a little too rich for you, then search around the Fans & Control Forum for recommendations on Panaflow or Papst models, but they may not be much cheaper (I know the Papst definitely are just as expensive, if not more, and don't include nearly as many accessories) and in a couple comparisons, including one done by The Mod Fathers, the AcoustiFan is quieter than even the vaunted Papst unit.

Here's my personal review of the AcoustiFans, and even a special mod I performed with the AF120CT model.

I'm not sure which CPU you plan to use the ThermalRight heatsinks on, but also notice that if you have a lower power Pentium 4, the SP-94 is so good, that with good case airflow control, you can even do without a fan on the heatsink (my silent machine, Sigma One, is done up exactly like that; see my review above, or this link here for the thread in the Gallery for Sigma One).

Good luck, and let me know if you have any other questions; also, if you get a chance, do let us know how things work out! We love to see happy silent computing converts.

-Ed

hitman47 · Post by **hitman47** » Sat Feb 14, 2004 2:20 am

Thanks mate that's exactly what I was after...

edwardng wrote:If you can find a better 92mm fan (AcoustiProducts' AcoustiFan AF92CT is my recommendation), then definitely go with 92mm.

The AcoustiFans were the exact fans I was looking at after their favourable reviews (well the AF92CT or AF80CT)!

edwardng wrote: I'm not sure which CPU you plan to use the ThermalRight heatsinks on

I am planning to use an Athlon64, thus I was considering SLK-948U or the upcoming SP-98; I feel I shall wait for the SP as you recommmend

edwardng wrote:Good luck, and let me know if you have any other questions; also, if you get a chance, do let us know how things work out! We love to see happy silent computing converts.

Will do mate!

Just to recap, you recommend an SP-94 with a AF92CT over an AF80CT !?
Kind Regards and Many Thanks

hitman47 · Post by **hitman47** » Sat Feb 14, 2004 2:40 am

Edwardng, just read your review of the Acoustifans, and you say:

I tried putting a 92mm Acoustifan on the SP-94 but its proximity to the PSU fan caused a wind turbulence sound, so I decided to skip on the fan for the CPU HS

Would this not happen to me too? Perhaps an 80mm fan would not have this turbulence problem?

Thanks again mate for all your help

Post by **Ralf Hutter** » Sat Feb 14, 2004 6:12 am

Here's a comparison of a 92mm Panaflo L1A and an 80mm L1A (as well as other HSFs too) on an SLK900 at 12V, 7V, and 5V.

Edward Ng · Post by **Edward Ng** » Sat Feb 14, 2004 6:56 am

Cheers! Glad to know I've been helpful.

I actually tried my spare AF80CT in that position and it did have the same turbulence issue, plus...

The turbulence wasn't really, really bad in any measure; it was primarily noticeable because Sigma One is so darn quiet. That, and the fact that I've gotten to the point of anal-retentivity with the noise

. I think the majority of people could live with the minor noise it introduces to the system. Proper insulation of the case with something like AcoustiPack might also eliminate the sound from outside once the case panel is closed, particularly if your case doesn't have a duct that goes directly to the CPU like mine does; that duct was channeling the noise right out for me.

And yes, the SP-98 plus AF92CT should make an incredible combination! I personally plan to use that setup later this year when I upgrade to Socket-939.

-Ed

JVM · Post by **JVM** » Sat Feb 14, 2004 7:02 am

Ralf Hutter wrote:Here's a comparison of a 92mm Panaflo L1A and an 80mm L1A (as well as other HSFs too) on an SLK900 at 12V, 7V, and 5V.

The Zalman, at idle, shows 25C at 5V all the way to 12V and how can that be? What am I missing?

Edward Ng · Post by **Edward Ng** » Sat Feb 14, 2004 7:09 am

It looks to me like the CNPS-7000's idle cooling potential is tremendous; I double-checked the figures and the load temp went up with the dropping of fan voltage, so, apparently, it's not an error. Pretty impressive!

-Ed

JVM · Post by **JVM** » Sat Feb 14, 2004 10:23 am

edwardng wrote:It looks to me like the CNPS-7000's idle cooling potential is tremendous; I double-checked the figures and the load temp went up with the dropping of fan voltage, so, apparently, it's not an error. Pretty impressive!

-Ed

The cooling seems impressive but what about noise? I've read some complaints of clicking at 5V and the review said something about a buzz or whatever and actually I don't mind air noise too much but buzzing, clicking, or any mechanical noise are things that trouble me.

Edward Ng · Post by **Edward Ng** » Sat Feb 14, 2004 10:41 am

A ThermalRight sink with an AcoustiFan will definitely make nothing but air noise

.

-Ed

JVM · Post by **JVM** » Sat Feb 14, 2004 1:14 pm

edwardng wrote:A ThermalRight sink with an AcoustiFan will definitely make nothing but air noise .

-Ed

Okay, but I have a Thermalright 800U with Nexus 80mm Real Silent Case Fan and it definitely doesn't produce anything but air noise. Actually, I can't really be certain the air noise is from the Nexus or SS 400.

My cpu temp is in the high 30's when just surfing the web. My case temp is like 33 to 34C. And I have the Sonata with pre-cut acoustipack blocking the Antec side holes. So, I don't have a case with great airflow and I have not made any modifications; and yet, I don't think my temps are all that bad, not great, but not all that bad.

hitman47 · Post by **hitman47** » Sat Feb 14, 2004 2:09 pm

Ralf Hutter wrote:Here's a comparison of a 92mm Panaflo L1A and an 80mm L1A (as well as other HSFs too) on an SLK900 at 12V, 7V, and 5V.

Cheers for that Ralf

edwardng wrote: Proper insulation of the case with something like AcoustiPack might also eliminate the sound from outside once the case panel is closed, particularly if your case doesn't have a duct that goes directly to the CPU like mine does; that duct was channeling the noise right out for me.

lol, thanks for the heads up! It is said that Acousti are bringing out out a precut for the Antec SLK3700-BQE, so I shall definately look out for that one.

edwardng wrote: And yes, the SP-98 plus AF92CT should make an incredible combination! I personally plan to use that setup later this year when I upgrade to Socket-939

Now your just copying me! I too cannot wait for s939 (although I believe I shall wait for the 90nm simply because they could be even cooler/faster - heaven forbid they won't go the way of the Presscot

)

Thanks again mate
Best wishes

Atragon · Post by **Atragon** » Fri Mar 26, 2004 11:12 pm

Regarding the turbulance and deadzone issues, what about slapping a gutted 92mm fan as a spacer between the HSF and the actual fan? Or for the more obsessed, building an adapter to duct a 120mm fan down to the exact footprint of the HSF itself.

vortex222 · Post by **vortex222** » Mon Mar 29, 2004 2:27 am

i only have an SLK800 on my barton, and i tried both the panaflo l1a and another 70 mm medium flow fan(cant remember the brand), and they both proformed about the same, givin the 70 mm ran at higher rpm, but the panaflo was quieter and also cooled the northbridge and power cercuits better, so i stuck with it. now i use a duct, and that has been the quietest yet, however at a cost of temp's.

the slk i found proformed better with the fan inversed to suck off the heatsink and it reduced the turbulance with my supertornado. and cpu temps went down by a couple C. as well the PSU spun at a slightly lower rpm. ~900 rpm. in that case it wouldnt really matter what fan was on it, only that it pulled enough cfm, and the larger fan may benifit more?