Need help with fan choice/reccomendation

[Radium_Angel]

This gets a little involved, please bear with me.

I have a Dell precision T5610 with twin Xeons

The main Xeon is actively cooled, but the air flows through the heatsink, and past the second heatsink, and out the back of the system. Because of this (factory) arrangement, the 1st CPU is fairly cool, but the second one gets warmer than I'd like. While I don't want to try to put a fan onto the 2nd heatsink (space considerations among other things) I can mount one (I think) on the exhaust vent of the rear chassis.

See pic here

 

Just to the left of the 2nd CPU is room for a cooling fan. which can exhaust out here

 

I have a 120mm coolermaster 3 pin fan which I manually held in place (it's too big to properly mount) and attached it to the motherboard, and it cooled the way I wanted it to...however....

 

There are two issues:

Dell uses a specialized 5 pin connector on the mobo for fans (to be controlled by the BIOS)  

See image here

https://c.76.my/Malaysia/dell-precision-t5610-workstation-socket-2011-motherboard-be5813-e93839-beginner28-1509-11-beginner28@5.jpg

(link because it's big) very upper right black connector

 

So I got a 5 pin to 4 pin adapter from eBay and it does work, and pulls out the hot air rather nicely, and cools that second Xeon.

But the fan runs at top speed because the mobo can't see it, which in the case of the coolermaster is a tad loud.

 

So, two things really.

I need a fan to mount inside and screw into the vent. I'm guessing 80mm? but I am unsure.

And then either an intelligent fan that the Precision can see and control, 

OR

something with a rheostat on it so I can adjust the speed manually.

 

Any ideas?

 

[boey]

I'm not sure if this would work but maybe you could try getting one of those SATA powered fan hubs that plug in via USB to the motherboard? I'm quite sure you can control fan speed via those

[Radium_Angel]

4 minutes ago, _d0nut said:

I'm not sure if this would work but maybe you could try getting one of those SATA powered fan hubs that plug in via USB to the motherboard? I'm quite sure you can control fan speed via those

There is an internal USB port on the mobo (just above the power supply) but routing the fan cable(s) might prove a trick.

[flibberdipper]

I'd imagine you could get a 92mm PWM fan of whatever you like and that should work fine. In the case of my OptiPlex 7010, the 5 pin is just a retarded-layout 4-pin.

[WoodenMarker]

Are you sure that the motherboard isn't 'seeing' the fan?

The motherboard fan header is probably sending a pwm signal which results in 100% rpm for 3pin fans. 

[Radium_Angel]

5 hours ago, WoodenMarker said:

100% rpm for 3pin fans

Apologies, this is probably what is happening, in more accurate terms, I just assumed that at 100% power from instant on, it meant the mobo didn't "see" the fan correctly.

[WoodenMarker]

20 hours ago, Radium_Angel said:

Apologies, this is probably what is happening, in more accurate terms, I just assumed that at 100% power from instant on, it meant the mobo didn't "see" the fan correctly.

You'll probably need a 4pin pwm fan if you want to control it from the motherboard.

Fan size is determined by the side of the fan frame or diameter. If you want to screw it into the case, it'll also be dependent on the distance between the holes.

for example, a 92mm fan is 92mm wide and the distance between the holes is 82.5mm.

If you just want to zip tie it to the case, just making sure the fan isn't too wide should be enough. If you're mounting it to the outside, make sure to get a fan grill and that it doesn't cover the rear i/o.

If you would like some fan recommendations, let us know where you're shopping / located and your budget.

[Radium_Angel]

2 hours ago, WoodenMarker said:

If you would like some fan recommendations, let us know where you're shopping / located and your budget.

This has been extremely helpful, thank you for the visual information.

As to where, etc. USA, online (ebay, newegg, amazon) and say no more than 35$?

[WoodenMarker]

9 hours ago, Radium_Angel said:

This has been extremely helpful, thank you for the visual information.

As to where, etc. USA, online (ebay, newegg, amazon) and say no more than 35$?

Did you figure out how much space is available for the fan?

[Radium_Angel]

55 minutes ago, WoodenMarker said:

Did you figure out how much space is available for the fan?

That would have been helpful had I posted that wouldn't it?

Sorry, here you go

 

(Space between grill and CPU) 1.5" (38.1mm)

Grill Height 3.25" (82.5mm)

Grill Width 4.25" (107.95mm)

Obviously not a square exhaust grill

 

And I stand corrected, the 2nd CPU does have an exhaust fan hidden within the shroud, and I missed it, but it's still drawing in CPU 1 air to cool with, and I feel a case exhaust fan would be helpful here

[WoodenMarker]

44 minutes ago, Radium_Angel said:

Grill Height 3.25" (82.5mm)

Grill Width 4.25" (107.95mm)

Seems like you'll be limited to 80mm's if you mount a fan to the inside but that might still help. 

The NF-A8 is an excellent option: https://pcpartpicker.com/product/XK8H99/noctua-case-fan-nfa8pwm

If you want to try fitting a bigger fan on the outside, a 92mm such as the NF-A9 may fit with zipties or screws with the holes at the edge of the grill enlarged without blocking the rear i/o. https://pcpartpicker.com/product/JhM323/noctua-case-fan-nfa9pwm

[Radium_Angel]

1 hour ago, WoodenMarker said:

Seems like you'll be limited to 80mm's if you mount a fan to the inside but that might still help. 

The NF-A8 is an excellent option: https://pcpartpicker.com/product/XK8H99/noctua-case-fan-nfa8pwm

If you want to try fitting a bigger fan on the outside, a 92mm such as the NF-A9 may fit with zipties or screws with the holes at the edge of the grill enlarged without blocking the rear i/o. https://pcpartpicker.com/product/JhM323/noctua-case-fan-nfa9pwm

80mm is more than fine, I just want something to help with exhausting the heat and an added benefit of cooling the 2nd Xeon.

Thank you kindly for the help

[Mathiau]

Hello,

Sorry to bring back an old thread but this has been hard to find, @Radium_Angel can you confirm the D/N number on the 2nd heatsink? Is it the 1TD00 ? I need a heatsink for a 2nd cpu for my T5610 and some that have said they are T5610 compatible, were not and were only 3 pipes on the heatsink.