What is better with XP120: Nexus blowing UP or DOWN?

Thorz · Post by **Thorz** » Sat Feb 26, 2005 8:21 pm

That's my question, I have been searching for the answer but I came with a ton of results. I am sure it has been answered before but I could not see it on the FAQ either.

I will mount this baby tomorrow and will plug the 120mm Nexus to my Vantec Nexus Multifunction controller. About the 120mm Nexus I have another 2 easy questions:

- Do I have to connect both connectors (the molex and the 3 pin one) or it can be run of the 3 pin one only? I ask because I have another 120mm Nexus that I will have as rear fan too.

- What is the minimun RPM to run this baby? The Vantec Nexus controller doesn't provide me with volt info, only RPM info.

Thanks a lot m8s.

Thunder · Post by **Thunder** » Sat Feb 26, 2005 8:44 pm

You only need to connect one or the other 3-pin or molex

nexus min rpm is around 600 rps I think

and you should probebly mount the fan blowing towards the heat sink

rtsai · Post by **rtsai** » Sat Feb 26, 2005 8:58 pm

If you connect the Molex and rewire it for 5V or 7V, is it still OK to plug in the 3-pin connector for RPM monitoring? Or will the 12V coming from the motherboard header do bad things when it is mixed with the 5V/7V combination from the Molex?

Post by **Rusty075** » Sat Feb 26, 2005 9:44 pm

Thorz wrote:That's my question, I have been searching for the answer but I came with a ton of results. I am sure it has been answered before but I could not see it on the FAQ either.

That's why we test such things in our reviews. Although the nexus wasn't included in the testing, the consensus from the 4 fans that were is that blowing down generally produced lower temps, although the difference was small.

Thorz wrote:- What is the minimun RPM to run this baby? The Vantec Nexus controller doesn't provide me with volt info, only RPM info.

Voltage doesn't matter. Neither does RPM's. Turn it down until one of three things happens: Its noise drops below the ambient noise in your room. Its noise drops below the noisier components in your system. Or until your CPU temp rises to a dangerous level.

Gorsnak · Post by **Gorsnak** » Sat Feb 26, 2005 10:29 pm

rtsai wrote:If you connect the Molex and rewire it for 5V or 7V, is it still OK to plug in the 3-pin connector for RPM monitoring? Or will the 12V coming from the motherboard header do bad things when it is mixed with the 5V/7V combination from the Molex?

It would do bad things. You'd be shorting the 5v and 12v rails if you did a 5v molex connection and plugged the 3-pin onto the motherboard. To avoid this you can just pull the red wire out of the 3-pin connector (tape the end up so it doesn't short on anything) and plug in just the yellow and black. If you wire the molex for 7v using the difference trick, you have to pull the black wire out of the 3-pin too, or you'll be shorting the 5v rail to ground. Again, bad things. I'm not sure if rpm monitoring works without the ground wire connected, though.

My Nexus doesn't start reliably at 5v. It's close, but not quite. 7 is lots, 6 or maybe even 5.5 would probably do.

Qwertyiopisme · Post by **Qwertyiopisme** » Sun Feb 27, 2005 3:23 am

Gorsnak wrote:
rtsai wrote:If you connect the Molex and rewire it for 5V or 7V, is it still OK to plug in the 3-pin connector for RPM monitoring? Or will the 12V coming from the motherboard header do bad things when it is mixed with the 5V/7V combination from the Molex?
It would do bad things. You'd be shorting the 5v and 12v rails if you did a 5v molex connection and plugged the 3-pin onto the motherboard. To avoid this you can just pull the red wire out of the 3-pin connector (tape the end up so it doesn't short on anything) and plug in just the yellow and black. If you wire the molex for 7v using the difference trick, you have to pull the black wire out of the 3-pin too, or you'll be shorting the 5v rail to ground. Again, bad things. I'm not sure if rpm monitoring works without the ground wire connected, though.

My Nexus doesn't start reliably at 5v. It's close, but not quite. 7 is lots, 6 or maybe even 5.5 would probably do.

I wouldn't connect the rpm wire at all when 7V-ing it, because when it is 7V-ed the fans' ground is the same as 5V for the motherboard, and (assuming the tach output is a full-voltage spike) the signal to the mobo would be 5+7V, 12V. I doubt the mobo would be able to read the fan output, and it may even break. (I dont know if a steady 5V to the tach output with 12V pulses will damage it, hell I dont even know exactly what type of siganl the third wire gives, but I assume it's something like this.))

Post by **Ralf Hutter** » Sun Feb 27, 2005 6:34 am

Thorz wrote: Nexus blowing UP or DOWN?

That's my question

Try it both ways in your own system. That's one of the neat things about the clip-on fan mounting on Thermalright heatsinks. You can flip the fan over in about 5 seconds and try it the other way to see which orientation works best in your own system. (If you're dexterous, you can even do it while the fan is running!

)

rtsai · Post by **rtsai** » Sun Feb 27, 2005 8:21 am

Gorsnak wrote:
rtsai wrote:If you connect the Molex and rewire it for 5V or 7V, is it still OK to plug in the 3-pin connector for RPM monitoring? Or will the 12V coming from the motherboard header do bad things when it is mixed with the 5V/7V combination from the Molex?
It would do bad things. You'd be shorting the 5v and 12v rails if you did a 5v molex connection and plugged the 3-pin onto the motherboard. To avoid this you can just pull the red wire out of the 3-pin connector (tape the end up so it doesn't short on anything) and plug in just the yellow and black. If you wire the molex for 7v using the difference trick, you have to pull the black wire out of the 3-pin too, or you'll be shorting the 5v rail to ground. Again, bad things. I'm not sure if rpm monitoring works without the ground wire connected, though.

My Nexus doesn't start reliably at 5v. It's close, but not quite. 7 is lots, 6 or maybe even 5.5 would probably do.

Thanks. I have the orange 120mm Yate Loon fans currently undervolted to 5V, and just didn't plug in the 3-pin connector. Maybe later I'll experiment with pulling out the 12V/ground wires out of the 3-pin connector and see if RPM monitoring still works.

Thorz · Post by **Thorz** » Mon Feb 28, 2005 1:59 am

Thanks for the answers. I guess blowing down it will be.
I have read about a person in abxzone that have some capacitors leaking after 24 hours of using the XP-120 on an Asus P4C800E-Dlx board (same as mine). I have bended slightly 2 capacitors (as stated by Thermalright in its homepage) for installing the XP120, is my system in some kind of danger due to this?

poohbear · Post by **poohbear** » Sat Mar 05, 2005 7:16 pm

Gorsnak wrote:
rtsai wrote:If you connect the Molex and rewire it for 5V or 7V, is it still OK to plug in the 3-pin connector for RPM monitoring? Or will the 12V coming from the motherboard header do bad things when it is mixed with the 5V/7V combination from the Molex?
It would do bad things. You'd be shorting the 5v and 12v rails if you did a 5v molex connection and plugged the 3-pin onto the motherboard. To avoid this you can just pull the red wire out of the 3-pin connector (tape the end up so it doesn't short on anything) and plug in just the yellow and black. If you wire the molex for 7v using the difference trick, you have to pull the black wire out of the 3-pin too, or you'll be shorting the 5v rail to ground. Again, bad things. I'm not sure if rpm monitoring works without the ground wire connected, though.

My Nexus doesn't start reliably at 5v. It's close, but not quite. 7 is lots, 6 or maybe even 5.5 would probably do.

Are you serious? We can't use the yellow sensor wire when undervolting it? Or is it only after you mod the wires manually? Because I just bought a Cooler Master Musketeer 1 and noticed it comes with a 3 colour wire which splits into 2 plugs, the red & black wires connect to the fan, and yellow sensor connects to the fan connector on motherboard.

So I'm kind of confused now .. can I use the sensor plug for the rpm monitoring or not?

mathias · Post by **mathias** » Sat Mar 05, 2005 7:40 pm

poohbear wrote: We can't use the yellow sensor wire when undervolting it? Or is it only after you mod the wires manually?

No, not really. The only problem is, you can't use a two wire RPM monitoring plug, the type that has a ground wire which is required by a few montherboards, and use something other that ground, such as +5v, +3.3v or -5 v, as ground. And even so, it would probably still work if rewired so that the rpm plug used a different ground, that is an actual ground, instead of what the fan is using for ground.

m0002a · Post by **m0002a** » Sat Mar 05, 2005 8:36 pm

According to the FAQ on the Thermalright website, air flow should be going down on their heatsinks. However, I believe that I read in a review somewhere that for the XP-120 there is only a 1 degree C difference when reversing the air flow direction. Obviously, the specific airflow inside your case could affect the results you get, so it probably would not hurt to try it both ways.

m0002a · Post by **m0002a** » Sat Mar 05, 2005 8:46 pm

Thorz wrote:I have bended slightly 2 capacitors (as stated by Thermalright in its homepage) for installing the XP120, is my system in some kind of danger due to this?

Only a problem if you damage the capacitors or short them out (if the leads touch something they should not touch). If you are careful, it should not be a problem. Just move them slowly and don't twist them and don’t push straight down on them. You can lean them over a bit (they don’t have to be upright).

But there is always a chance that you could break the leads or damage the capacitor, so there is a disclaimer on the Thermalright instructions about this. Usually, the longer the leads, the easier it is to bend them out the way. If the leads are visibly coated with solder of the top of the motherboard, or if the leads are very short, then that could be a complicating factor.

rtsai · Post by **rtsai** » Sun Mar 06, 2005 6:32 am

poohbear wrote:
Gorsnak wrote:
rtsai wrote:If you connect the Molex and rewire it for 5V or 7V, is it still OK to plug in the 3-pin connector for RPM monitoring? Or will the 12V coming from the motherboard header do bad things when it is mixed with the 5V/7V combination from the Molex?
It would do bad things. You'd be shorting the 5v and 12v rails if you did a 5v molex connection and plugged the 3-pin onto the motherboard. To avoid this you can just pull the red wire out of the 3-pin connector (tape the end up so it doesn't short on anything) and plug in just the yellow and black. If you wire the molex for 7v using the difference trick, you have to pull the black wire out of the 3-pin too, or you'll be shorting the 5v rail to ground. Again, bad things. I'm not sure if rpm monitoring works without the ground wire connected, though.

My Nexus doesn't start reliably at 5v. It's close, but not quite. 7 is lots, 6 or maybe even 5.5 would probably do.
Are you serious? We can't use the yellow sensor wire when undervolting it? Or is it only after you mod the wires manually? Because I just bought a Cooler Master Musketeer 1 and noticed it comes with a 3 colour wire which splits into 2 plugs, the red & black wires connect to the fan, and yellow sensor connects to the fan connector on motherboard.

So I'm kind of confused now .. can I use the sensor plug for the rpm monitoring or not?

I think "it depends".

On my Yate Loon fans, I have a choice of Molex connector, or 3-pin header (power + RPM monitoring). Since both the 4-pin and 3-pin headers provide power, they shouldn't both be used at the same time.

If, on the other hand, you have a fan with a Molex power connector and a 3-pin header that contains only the RPM wire (e.g., does not have the extra wires to draw power through the 3-pin connector from the motherboard), then you are probably fine. The power will come from the Molex (PSU), and the RPM metrics will go to the motherboard.

Derek Baker · Post by **Derek Baker** » Sun Mar 06, 2005 10:35 am

When I installed my XP-120 I tried the Nexus both ways, and it was several degrees cooler sucking rather than blowing. The fact I have a 120mm exhaust very close to the cpu fan may have something to do with it.

The best advice is simply to try it for yourself.

mathias · Post by **mathias** » Sun Mar 06, 2005 11:20 am

I agree that it's usually best to try it boh ways, but wouldn't those vibration dampening strips that come with SI97s and I'm assuming XP120s too get worn out?

Post by **Ralf Hutter** » Mon Mar 07, 2005 6:41 am

mathias wrote:I agree that it's usually best to try it boh ways, but wouldn't those vibration dampening strips that come with SI97s and I'm assuming XP120s too get worn out?

??

I attach the strips to the fins and the fan just sits on top of them, with the only pressure being that supplied by the fan clips. I can't see how flipping the fan over (even millions of times) could possibly cause any wear on those strips.

Spod · Post by **Spod** » Fri Mar 11, 2005 6:23 am

It could if you (incorrectly) stuck the strips to the fan instead of the heatsink, meaning you had to unstick them and restick them on the other side of the fan every time you flipped the fan. Otherwise, I agree, they're perfectly robust for their intended use.

Tibors · Post by **Tibors** » Fri Mar 11, 2005 10:27 am

I didn't even notice (or expect) those strips are sticky

But the pressure from the clips is enough to keep them in place anyway.

What is better with XP120: Nexus blowing UP or DOWN?

What is better with XP120: Nexus blowing UP or DOWN?

Re: What is better with XP120: Nexus blowing UP or DOWN?

Re: What is better with XP120: Nexus blowing UP or DOWN?