Pic of "Dead Zone" created by a Tornado on SLK-900

Hey all,
Was lapping me SLK-900u last night and noticed this, the substantial "dead zone" in the center of the heatsink, created by a Tornado. It just illustrates the lack or airflow in the center of the block. I didn't think it would be that big. I suppose a duct would sort that out.
Just thought I'd share.

Whoah, thats bigger than I expected. A duct should solve that. Thats why low cfm squirrel cage fans work so well, they hit the air right above the core of the cpu.

Damn that is huge You can try what was suggested over in this thread . I'm going to give it a try

See, i'm not sure if I can fit a duct. The Tornado is tall enough as it is, and i'm makin' my own custom window with 2 blowholes, one of them above the Tornado. There may not be room for a duct in between the blowhole fan and Tornado.
Although the case is big enough (below), won't know 'til i put the window in if a duct will fit.


EDIT: Sorry to anyone who just saw that thread, it wasn't me who posted it. As you can see, it's gone.

You could cut the innards out of another fan that size and strap it on to the hs, then screw or glue the tornado on top of that....

Yeah, heard of that before, but don't have a spare fan to chop up. And even if I did, I'd hate to cut up a usable fan.
Might try cardboard or summit.

how did you guys attach it to your HS after u put the shroud on. wouldnt the clips that come with these heatsinks not work now?

Go go 10cm shroud / blower

wow, thats a crazy big dead zone. Im gonna reevaluate my slk and tornado.

how bad is it to have that big of a dead zone?

I mean the tornado is the best fan..right..so it doesnt matter how big of a dead zone it has..

but changing that..would it really increase performance that much?

that deadzone is why ppl get better temps using an 80mm fan. your practically wasting half the heat sink if you go with a 92mm. the best thing you can do if you want to use a 92mm is to cut a hole in the case above the heat sink, mount the 92mm there, and build a shroud that goes from the new blowhole to the heat sink.

i use a sunbeam overclocker duct kit, and my problem right now is the duct makes an extremely sharp 90 degree turn at the heatsink, and all the air comes out on one side of the duct. i still havent thought of anything i can do about this, except mount the duct off-center.

If I had that heatsink, I'd make a duct for direct air intake.
Option a)
hole in case(or some custom side of case), just directed to heatsink, big fan on hole, duct directly to heatsink
Option b)
120mm fan in back of case on normal mounting position, tube-style duct leading to heatsink to place where you mount fan

Both options are described in tips sections on www.overclockers.com

It's a real sin to waste so much of this Thermalright heatsink.

do NOT do a duct with a 120mm fan. 120mm fans dont put out enough pressure to send air through a tube and a heat sink. a 80cfm 120mm fan will give you like 3 cfm in that config. just cut a hole in the side of your case and mount an 80mm fan there with a custom made duct to the heat sink.

on my other rig, i made a ghetto cardboard duct by folding it around the edges of my 80mm side case fan to blow air onto the hs....looks ghetto but works....you can even direct the air by slightly angling the sleeve....

cstarritt said:

do NOT do a duct with a 120mm fan. 120mm fans dont put out enough pressure to send air through a tube and a heat sink. a 80cfm 120mm fan will give you like 3 cfm in that config.

Click to expand...

Not always true. If the fan is strong enough, the decrease in the output size of the duct will only increase it's pressure.

Well, I could go and grab some P/Q curves for high end 120mm fans vs high end 80mm fans or low cfm 120mm fans vs other fans at certain p/q ranges but then some would ask me to explain them in this thread. I will get the P/Q curves in a PM to those that want them. Anyways, a 130cfm 120mm mm fan will perform worse than even a 80mm 84cfm fan..most likly even a 68cfm 80mm fan EVEN if its ducted down through a long funnel~fan attached to the side of the case panel. The larger fans usually just do not put out the same pressure as you would think. A 120mm 190cfm delta screamer with those air stabilizing vanes will MAYBE perform like a 92mm 119cfm fan on a thermalright thin fin heatsink. The problem is you get nearly the same performance but LOUDER..and more power draw. A normal adapter attached to the heatsink with a "normal" fan would basically choke~cause such pressure that most air blows backwards instead of going through the fins. I would say ducting a 92mm tornado fan to the large thermalright heatsinks from the side of your case panel would be your best bet on noise/absolute performance unless you get ahold of one of HOOT's blowers from grainger. Chances are you could 7v mod a 92mm tornado and still get the same temps if its ducted correctly because its hitting all of the heatsink evenly. I hope this helps out somewhat because I have tested stuff like this quite a while. It is quite frustrating thinking a high cfm~large 120mm fan~ low pressure fairly low noise fan will work better than a noisy 80mm fan and then you find out the temps arnt as good as you hoped. You have to remember most fans spit out their airflow in a spiral and a duct is almost a 90° to the airflow. That really kills the cfm and builds up pressure to a point that the fans almost stall out depending on the fans. Comair rotron and delta's websites have an exhaustive listing of their fans P/Q tables. Please read them and compare what a certain fan does vs another at such and such pressure. It will help you understand what the fans can actually do vs what you hope~think they can do.

Well, can't wait to get my blowhole fans, so i can start on my homemade duct.
By the way, the Tornado is only running at 7v using the "molex volt mod".
--> I'd rather get 36*C idle / 50*C load than listen to that full Tornado racket.

Foxie3a said:

how bad is it to have that big of a dead zone?

I mean the tornado is the best fan..right..so it doesnt matter how big of a dead zone it has..

but changing that..would it really increase performance that much?

Click to expand...

Are you serious dude?

Thats like saying some pitcher in baseball can throw 120 miles per hour so it doesnt matter that he never throws strikes.

Thats like saying some pitcher in baseball can throw 120 miles per hour so it doesnt matter that he never throws strikes.

Click to expand...

Ok, not the best analogy , but you can see his point.
The area around the "Dead Zone" is tarnished, obviously because it's in contact with alot more air.
Imagine if the HS base, directly above the CPU core, recieved as much air as the circled tarnished area. Then there'd be constant direct airflow right above the core = good news.

cstarritt said:

do NOT do a duct with a 120mm fan. 120mm fans dont put out enough pressure to send air through a tube and a heat sink. a 80cfm 120mm fan will give you like 3 cfm in that config. just cut a hole in the side of your case and mount an 80mm fan there with a custom made duct to the heat sink.

Click to expand...

Everything is a matter of how it's done. Good duct for 120mm fan - far better than 80mm fan. I do NOT believe that 120mm fan is worse.

You may be right, but not always. Assuming that duct's narrowing is rapid, you're 100% right. But if duct has proper length and shape, you'll see its great advantage over using smaller fans.

Other possibility - blower. Blowers are rather big and hard to mount on case, but there's a possibility to use not so huge without problems.

Mount one in case (to case) to blow directly on heatsink. Then you make direct duct intake from case backside or hole on side.