Push pull config with Scythe Infinity?

[giantjoebot]

I'm thinking of buying a Scythe Infinity, and putting a second fan on it for a push pull config, but where or how do I connect the second fan. Do I buy or make a splitter and connect both of them to the CPU header on the motherboard, or is that pulling to much from one header?

 

[DerwenArtos12]

Originally posted by: giantjoebot
I'm thinking of buying a Scythe Infinity, and putting a second fan on it for a push pull config, but where or how do I connect the second fan. Do I buy or make a splitter and connect both of them to the CPU header on the motherboard, or is that pulling to much from one header?

a splitter could work depending on the fans but, you'd probabaly be better off running the second off your mothebaord controlled case fan header or just controlling them manually.

 

[giantjoebot]

I'm not sure if that will work. I got a ASUS nforce 570 motherboard, and in the bios it has an option to lower the fan speeds. I have it currently on the lowest setting, and I think that it runs the CPU, and the case fan at different speeds. I'll have to double check when I get home. I'm at work right now.

The fans that I'll be using are yateloon 120mm 1350 rpm, with 3pin connectors.
Operation Voltage: 6.5~13.8 Volts
Input current: 0.30 Amp Max
Thats weird, I run these fans on 5 volt all the time, but it says 6.5~13.8

I found a splitter for sale here
http://www.performance-pcs.com...h=289&products_id=1311

In the description says

The user should excercise caution when hooking up higher powered fans as the motherboard headers usually have a limited current capacity.

EDIT: just checked the fan speeds, and they do run pretty close. The CPU fan ramps up to double the speed for a few seconds every once and a while, and the case fan doesn't.

 

[DerwenArtos12]

Originally posted by: giantjoebot
I'm not sure if that will work. I got a ASUS nforce 570 motherboard, and in the bios it has an option to lower the fan speeds. I have it currently on the lowest setting, and I think that it runs the CPU, and the case fan at different speeds. I'll have to double check when I get home. I'm at work right now.

The fans that I'll be using are yateloon 120mm 1350 rpm, with 3pin connectors.
Operation Voltage: 6.5~13.8 Volts
Input current: 0.30 Amp Max
Thats weird, I run these fans on 5 volt all the time, but it says 6.5~13.8

I found a splitter for sale here
http://www.performance-pcs.com...h=289&products_id=1311

In the description says

The user should excercise caution when hooking up higher powered fans as the motherboard headers usually have a limited current capacity.

EDIT: just checked the fan speeds, and they do run pretty close. The CPU fan ramps up to double the speed for a few seconds every once and a while, and the case fan doesn't.

It really doesn't much matter if they ramp at different speeds does it? who cares if they're running out of synch from one another. that could actaully be beneficial considering the vortex affect caused by putting two fans spinning the same direction too close together.

 

[giantjoebot]

I looked all over the place and couldn't find anything on vortex effect. Could you explain it, or point me to a link that does?

 

[DerwenArtos12]

Sure. It's not a technical name first of all, a more technical name would probably be cyclone effect. Anyway, standard rotary fans move air in two directions, linearly, or from one side to the other, and in a spiral the same direction that the blades are moving. The pitch or angle of the blades determines what percentage of the air being moved is linear or rotational. Lets just say for example that the fan moves 100cfm total and that it has your standard square edged and flat blades and at a 45* degree pitch. That fan should move roughly equal ammounts of air rotationally and linearly. However, if you put another one of those fans sandwiched right up agianst it the air is already moving in the same direction as the blades, so the total air moved by the fan is going to be roughly half, as it can't move the air rotationally only linearly. This can be overcome and actually used by putting counter rotating blades next to each other. With counter rotating blades the efficiency of the second set of blades actually goes up, and dramatically because the air is moving in the opposite direction of the blades. A similar but much less substantial effect happens when the fans and spinning different rpms with the lower rpm being put first in line. The air will already be moving rotationally but, not at the same rate of the second fan so it won't loose nearly as much efficiency as if they were spinning at the same speed. Keep in mind though that this half and half fan is not remotely typical of computer fans, most computer fans, are rather inneficient and move less than half their air linearly with some exceptions.

 

[giantjoebot]

OK, I understand, but the fans aren't sandwiched. I play around with fans all the time. Hell I buy case fans just to play with. I have tried sandwiching 2 fans, and yeah that actually has a negative effect in several ways. But in a push pull config on a heatsink like the Scythe Infinity they are separated by the heat sink. One on one side pushing air, and one on the other side pulling air.

I have an Antec 900 case. It has the option of putting 2 120mm fans in 3 of the drive bays in a push pull config. I use this option, with 2 of the same rpm and model fans, running at the same constant speed. 5volt modded 1350rpm Yate Loons, so they run at about 600-700rpm. The result of that push pull config is an increase in air movement. You can easy tell by sticking your hand in front of the fans. I don't think that the total air movment is double, but its a lot more than one fan alone. Now the distance between the 2 fans is greater than it would be with the Scythe Infinity heat sink.

Plus wouldn't the direction of the air movement be some what broken up, and be moving in a more linear direction by the heatsink fins anyways?

 

[DerwenArtos12]

Originally posted by: giantjoebot
OK, I understand, but the fans aren't sandwiched. I play around with fans all the time. Hell I buy case fans just to play with. I have tried sandwiching 2 fans, and yeah that actually has a negative effect in several ways. But in a push pull config on a heatsink like the Scythe Infinity they are separated by the heat sink. One on one side pushing air, and one on the other side pulling air.

I have an Antec 900 case. It has the option of putting 2 120mm fans in 3 of the drive bays in a push pull config. I use this option, with 2 of the same rpm and model fans, running at the same constant speed. 5volt modded 1350rpm Yate Loons, so they run at about 600-700rpm. The result of that push pull config is an increase in air movement. You can easy tell by sticking your hand in front of the fans. I don't think that the total air movment is double, but its a lot more than one fan alone. Now the distance between the 2 fans is greater than it would be with the Scythe Infinity heat sink.

Plus wouldn't the direction of the air movement be some what broken up, an dbe moving in a linear direction by the heatsink fins anyways?

It's going to be increased, I'm pretty sure I said that, perhaps cryptically but, I do agree given the spacing provided by the front bays of about 4.5" it would bet it's about 1.75x as much as a single fan, especially with that low of rpm. I was just explaining the over-all effect...

 

[giantjoebot]

I guess it just comes down to trying it out. I like to play with fans anyways, so I can always buy the splitter for $5, and try it out both ways. But your input has given me a lot to think about, and to experiment with. I have a slightly higher RPM Yate Loon that I can try to see if the overall effect is different. There are some other fans that I have been meaning to buy, and try out, so I'll play around with it, and see what works best. I'll make sure to post the results, but its going to be a while until I get payed, buy the cooler, shipping, and there is getting around to doing it. So I can't really say, but when I get it done, I'll let you know how it went.

Besides, I hate it when people run threads, and end it with, I figured it out, but do say how they figured it out.

 

[DerwenArtos12]

cool, I'll keep my eyes out. IMHO the best fans on the market right now are Scythe Slipstreams for case fans and Zalman ZM-F3's for heatsinks and radiators.

 

[giantjoebot]

Yeah, I have been trying to buy one of those Scythe Slipstreams for a while, but the 800rpm one that I want is always out of stock. I want to get at least one so that I can compare it to my Yate Loons.

So far nothing beats my Yate Loons on 5 volt for noise and air movement. I have some fluid dynamic bearing scythe fans, and they come close, but the Yate Loons move more air. Pluse the Yate Loons are cheap if you buy a bunch here
http://www.jab-tech.com/YATE-L...-D12SL-12-pr-3009.html

Why are the Zalmans better for heatsinks and radiators?

 

[idiotekniQues]

i hooked up a second scythe as a pull fan on my tt ultra 120-x using zip ties. was a pain in the ass cause you have to do it after getting the heatsink on the mobo so you can screw it into the backplate.

it didnt do much for my temps so i got rid of it next time i worked on my stuff. with my p180 case the rear exhaust fan is so close to the TT ultra that it pretty much acts as a pull fan as it is.

 

[giantjoebot]

the scythe infinity is made so that you can attach a second fan without using zip ties. How, where did you plug the second fan in. Did you use a splitter or another motherboard header?

 

[error8]

I run a Thermalright ultra 90 in push an pull configuration, and I have one fan connected to the cpu header and the other one has the wires soldered to the firsts one, except the yellow wire which just lies around there somewhere. The thing is that it lowered the temperatures with just 3 C, but I keep them like this anyway. I like the jet engine noise that they make when the cpu starts to load.

 

[giantjoebot]

Thats a great reason! Its about as good of a reason as mine. I run my CPU at stock speeds, I just want to do it for the fun doing it, and to see how cool I can run with low RPM fans.

So the way you have it is the same as a splitter, and it doesn't give you any problems? What kind of fans are you using?

 

[error8]

I don't have any problem at all and I'm running the cooler like this for some 6 months or so. I have two noname 92 mm fans that spin at 2500 rpm. And yes it's the same thing as using a splitter. Don't think that you will somehow overload the cpu header and damage the motherboard with two usual fans. If you probably want to use two 120 mm fans that spin at around 5000 rpm, then maybe some damage might take place, but I doubt you will do that.

 

[idiotekniQues]

i just plugged in the pull fan onto the piggy back of the rear exhaust case fan power plug. i ran the push fan into the cpu fan header on the mobo.

 

[giantjoebot]

So you both ran them off the CPU header.

 

[DerwenArtos12]

Originally posted by: giantjoebot
Yeah, I have been trying to buy one of those Scythe Slipstreams for a while, but the 800rpm one that I want is always out of stock. I want to get at least one so that I can compare it to my Yate Loons.

So far nothing beats my Yate Loons on 5 volt for noise and air movement. I have some fluid dynamic bearing scythe fans, and they come close, but the Yate Loons move more air. Pluse the Yate Loons are cheap if you buy a bunch here
http://www.jab-tech.com/YATE-L...-D12SL-12-pr-3009.html

Why are the Zalmans better for heatsinks and radiators?

Because of the blade design on the slipstreams they have lower static pressure so the CFM loss from blowing across heatsink fins or radiator fins is much greater. There are some exceptions to this rule with really exotic blade designs but, in general, fewer and wider blades are better than a bunch of thin blades when having to deal with resistance.

 

[DerwenArtos12]

Originally posted by: error8
I run a Thermalright ultra 90 in push an pull configuration, and I have one fan connected to the cpu header and the other one has the wires soldered to the firsts one, except the yellow wire which just lies around there somewhere. The thing is that it lowered the temperatures with just 3 C, but I keep them like this anyway. I like the jet engine noise that they make when the cpu starts to load.

You have to keep in mind when planning something like this that a heatsink is only capable of moving a certain ammount of heat away from the CPU IHS and that each heatsink is designed to have that amount of heat dissipated with a given cfm of air. Once you exceed that cfm, saying that the law of diminishing returns applies is a bit of an understatement and there is actually a point where higher CFM will increase temperatures but, generally that is above 1000CFM.

 

[giantjoebot]

Yeah I already learned that concept when I purchased a fan for exhaust that almost did 100cfm. Same goes for case fans. There is a point where you can't move any more heat out. But on the other side you want to at least move enough air so that heat doesn't build up in the case. I have a media server in a P180 with 4 Yate Loons on 5 volt, and while it work pretty good most of the time, when I was stress testing it the heat built up and the temps got pretty high. You could feel the hot air coming out.

So it will probably help more with load temps then it will with idle temps. Right now I'm using a Scythe mine with a Yate Loon, but the temps should be lower. It might also be due to thermal paste install though. I want to use the scythe mine in something else so I figure its a good time to try out the scythe infinity.