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difinitive thread on Smart Fan 2 Vs competition (lets settle this finally)

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Aug 12, 2002
Ok. I want to get all this info in 1 thread so we can go back and forth on this without having to look in 20 different threads. now we all know the delta and tornado are the best coolers because of their direct airflow, but something doesnt jive with me. maybe someone can put this issue to rest for once and for all. first off. we cant compare a smart fan 2 with a tornado or delta unless someone finds a way to get both pumping the same cfm of air as one another. granted 10 or 20 cfm isnt that big of a deal but it probably accounts for most of the temperature difference. secondly the fins on my delta i have right here just make the air flow streight and not in a spiral. i still feel a dead spot in the middle.

now another thing. though the smart fan may not be as good as a tornado, it is still better than if someone wanted to put a panaflo or some other regular fan on top is it not. those do not have fins to streighten the airflow. has anyone done any real testing on this to see what the actual temp differences are. i mean we are all speculating. i think at most, with equal cfm, you will see maybe 1-2 *c difference and that is on the high end of my gut instinct. anyone actually try this. lets end this once and for all.
i am not trying to argue anything you are saying. just wanted to ask a couple of questions.

what are you using to detect the dead spot that you are feeling?
I would personally like to own a smart fan II...in fact I am going to buy one with my new swifttech HSF...(this is while I wait for a month or so to order a vapochill)...i like that I don't have to have a controller on the outside to control the fan...the fan controls itself and doesn't get TOO terribley loud when I am just surfing, and speeds while I am playing a game...others I would have to buy extras to have the same capability (and the Tornado is too damn loud...my friend has one)
I have seen some online comparisons between the two and the difference in temp is larger than 1-2 degrees. Ill try to find them and post a link.

The SF2 does seem good if you want the temp controlled feature.

well so far we have said nothing new. the smart fan is definetley better than a regular 80mm fan since it has good cfm/db ratio, but is it comperable to a delta/tornado?

that is the meat and potatoes

if its not we can always use a 7v mod on the fan or rheo a delta down to lower cfm for the noise

would a tornado @ 60cfm still be as good as a smart fan II at 60cfm. that is basically what i am asking.
big_bertha said:

would a tornado @ 60cfm still be as good as a smart fan II at 60cfm. that is basically what i am asking.

How would you determine when the tornado is at 60cfm?
im just theorizing

at equal volumes of air... what is the temp difference. of course the delta is better thana smart fan 2 sicne it gets 10cfm better, but what happens to the temperature difference if the air volume moved is the same
Yeah, id like to hear the results....I looked back through the forums and it looks like only one person provided real numbers comparing the SM2 to the Tornado, so its hard to say if they are really accurate.

One thing to note is that a SF2 on full power usually runs faster than the rated 4800 (a lot of people have said this) so its airflow is probably higher than 75cfm at this speed.

It seems like it would be hard to base it on CFM, probably better to compare the fans at the same RPM level using rheos to get it just right. Not exactly the same CFM but it will be fairly close....

this weekend i will pick both up a bigfoot computers (10 min drive)

i will post results shortly after to settle this
rippedsocks said:
i have a smartfan II and its SOOO loud like as loud as an airconditoining unit

The Vantec Tornado is 7 decibels, that is, 70%, louder. Almost twice as loud. I don't know the exact dba rating of the Delta, but I'm sure it is also nearly twice as loud as the Smart Fan 2.
rippedsocks said:
then ill never be getting a tornado its not worth it....

What you could do is get a windowless case, or at least a case with only one window, and line the inside of the case with sound insulation pads. It can amount to much less noise.
Just so you know, the smart fan doesn't actually have a brain and the air pasing through doesn't respect it any more for being more learned.

Any certain amount of airflow will cool very similarly to a similar amount. Each fin and fan arrangement will cause variance.

The advantage to a smartfan is that (in an ideal system) there will be less "wasted" flow. When the temperature is reasonable, it won't increase its speed. That point of "reasonable" varies between users and many create situations where it'll never slow.

I don't know if channelled airflow is very important, it makes sense that it should overall help (keeping the air in the heatsink longer), but the amount of gain probably depends on the design of the heatsink.
Just to let you know, my SLK-800 with Smart Fan II works well enough, but if you reverse the air flow so that it sucks air through the fins of the heat sink and leave the side of the case off, it performs much better (for me). With the side on, the temps are worse. I think the problem with the Smart Fan is that it doesn't direct air as effieciently as the Tornado. Even though all tests of SLK-800 with Smart Fans and Tornados show the Tornado winning, doesn't mean it's because of higher cfm. I think the Tornado is a more efficient fan in terms of blade design. If I had a rheostat, you can bet I'd have a Tornado. Didn't know the Smart Fan hated my SLK-800 until after I bought it. And to think that I was on the fence over getting either the Smart Fan or the Tornado. I decided that noise was more important. Now I'm not so sure.

Intel P4 2.53 and a MCX 4000

These are all after a half hour period so air has had time to get hot in the case. Note that temps are higher since the video card has had time to heat up ambient temps alot with the airflow basically killed.

With case fans ON:

idle = 31*C
full load = 36*C

idle = 30*C
full load = 36*C

Smart Fan 2
idle = 31*C
full load = 37*C

With case fans OFF:

idle = 33*C
full load = 41*C

idle = 33*C
full load = 40*C

Smart Fan 2
idle = 35*C
full load = 44*C

There you have it. This was with a stock P4 at default speeds. There was no difference in idle temps between even the delta and the smart fan, which is odd, but that is because i have a well ventilated case (over 400cfm total moving around) when the case fans were turned off the idle temps start to rise, and after only half an hour were 3*C hotter than idle with the case fans on. the numbers speak for themselves but the difference was less than what i thought. more likely a result of the cfm difference than anything else. if all you have is a good heatsink, then no matter what the cpu is gonna get hot. If you have good airflow than the fan makes little difference since the air current A: keeps cold air around the cpu fan intake, and B: actually cools the cpu slightly by moving cold air around the mobo and pushing some more air through the pins on the HS. i have 2 120mm fans over the mobo so that may account for the low temps. anyways... there you have it. with the MCX4000, having air turbulence "Stoppers" on a fan does make a difference, however small.

next up is to try and make all the fans blow at the same rate. for this test i just put them all at max. maybe then i can give them all a fair comparison based on the same air volume pushed