Please ell me how to increase cooling in an Optiplex 990 Case?

[kapalua12]

This is a business computer and runs pretty quietly but the stock Dell rear exhaust fan seems puny.

current components :
990 Mini Tower
16 GB DDR3 1330 RAM
i7 2600
Vertex 3 MAX IOPS SSD OS drive
Seasonic 650 X Gold Modular PSU
WD HDD 1TB Black 64 MB cache storage drive
Runs a NEC PA271w-bk 27-Inch 2560 x 1440 monitor

I have a stock AMD fanless HD6450 GPU which I want to upgrade. I don't do a lot of gaming but do video editing and streaming video. I wan to upgrade this GPU to something more powerful but am space limited in terms of length as the SATA headers will end up underneath the back end of the GPU if it's much over 7 inches in length, unless the GPU leaves about an inch under the back end for room for the SATA headers.

There seems to be room to add a front 120 mm fan inside the front grill which is fairly open to bring more air into the small case, but how would I power this fan to which connector so it was temperature controlled and only ran when needed?

Secondly, are there after market fans to replace the rear exhaust fan which seems to be 87 mm which seems cheap and an odd fan blade diameter?

All advice welcome. Thanks.

 

[nipplefish]

There seems to be room to add a front 120 mm fan inside the front grill which is fairly open to bring more air into the small case, but how would I power this fan to which connector so it was temperature controlled and only ran when needed?

You'd need to look for a 3-pin fan header on the motherboard. There may be one towards the front edge of the board for exactly that purpose. Otherwise you'd need to get a fan controller if you wanted your fans to be temperature controlled; they will run constantly if you run them directly off the PSU.

Secondly, are there after market fans to replace the rear exhaust fan which seems to be 87 mm which seems cheap and an odd fan blade diameter?

Measure the entire fan edge to edge, not the blades. Sounds like it might be a 92mm which are pretty common.

 

[kapalua12]

Thanks. Where can I get a simple fan controller that will be simple and out of the way?

So measure the fan's outer housing ? It's square so outer rim to opposite outer rim?

Or do you mean the circumference of the circle in which the blades spin? The current fan says it is a 77 cfm fan. On NewEgg, most of the 80 mm fans are much less than that. Am I wasting my time changing that rear case fan which draws air from the case?

 

[kapalua12]

You'd need to look for a 3-pin fan header on the motherboard. There may be one towards the front edge of the board for exactly that purpose. Otherwise you'd need to get a fan controller if you wanted your fans to be temperature controlled; they will run constantly if you run them directly off the PSU.

I don't find a second fan header on the MB. Just the one for the rear case fan.

kapalua

 

[ElFenix]

per the specifications there are 2 fan connectors in an optiplex 990:
http://support.ap.dell.com/support/...UID-6FE73CA5-9960-4E9F-9513-B634A9F69D40.html

the connectors are 5 pin which is not common (fans are usually 3 or 4 pin nowadays).

a fan can be driven straight off the power supply. many fans come with the adapter to run off the power supply. that will take power from a 4 pin molex connector. as you've already put an aftermarket supply in there you should have several available.

a controller that fits into a slot on the back is good for one fan:
http://www.newegg.com/Product/Produc...eam-_-11995073

there are others that come in boxes to fit in the front of the computer as well available at the bottom of that page there.


measure a fan along a side, corner to corner.

 

[kapalua12]

Thanks! Is it a reasonable plan to put a 120 mm fan inside the front grill? There's nothing else there but a metal panel with a bunch of holes in it. hat front grill will provide some resistance to air flow since it was not designed for a fan other than being full of weird shaped holes.

I want to bring in more cool air obviously but should I upgrade the rear fan too?
I realize this computer is becoming much more than it was originally intended to be in terms of high end hardware.

What brand fan is the quietest? What should I look for. Thanks so much for your help!

kapalua

 

[kapalua12]

Looking at this link:
http://support.ap.dell.com/support/e...4A9F69D40.html

there is one 5 pin connector for a case fan and one for the processor fan. None others that I can easily use to power and throttle the 120 mm front case fan if I were to install one. Please correct me if I am not seeing this right.

kapalua

 

[ElFenix]

Looking at this link:
http://support.ap.dell.com/support/e...4A9F69D40.html

there is one 5 pin connector for a case fan and one for the processor fan. None others that I can easily use to power and throttle the 120 mm front case fan if I were to install one. Please correct me if I am not seeing this right.

kapalua

that looks right to me.

does that case not use dell's old practice of using a duct to pull air through the heat sink and directly out the back?

 

[kapalua12]

does that case not use dell's old practice of using a duct to pull air through the heat sink and directly out the back?

Nope, no duct. The rear case fan is open to the inside of the case.

I wanted to know the best brand of aftermarket fans to replace the rear case fan, but then I would need a 5 pin one!

If I wanted to increase air in the case, I wanted to add a 120 mm fan to the inside of the grill on the front of the case pulling air into the case, but there is no MB connector there and so would have to do the PCI slot thing or put in a fan controller....not sure it's worth it.

 

[dawp]

Depending on the pin-out for the fan header, a 3 or 4 pin fan 'may' work. 5-pin fans are non-standard and you may be out of luck connecting your motherboard to an off the shelf fan.

Without knowing the wiring for the headers, I'm not sure I would risk plugging a standard fan into your board. You may want to contact DELL and ask them if a 3 or 4 pin fan will work on those headers.

DELL has a history of using non-standard, i.e. proprietary, things in their systems.

Your best bet is to get a fan and hook it up to your PSU. Most come with an adapter so you can connect it to your power supply.

 

[ElFenix]

If I wanted to increase air in the case, I wanted to add a 120 mm fan to the inside of the grill on the front of the case pulling air into the case, but there is no MB connector there and so would have to do the PCI slot thing or put in a fan controller....not sure it's worth it.

if there's a grate you can just zip tie the fan to the grate. won't be pretty but then no one is looking inside anyway.

if there is a 4 pin power connector (scroll down to molex 8981) from the power supply a fan can run off that. most retail packaged fans come with the adapter.

get a quiet fan and you won't need a controller. an 800 or so rpm scythe slipstream is a good choice.


according to the pinout chart the 5th pin isn't even used.
http://pinouts.ru/Motherboard/dell_fan_pinout.shtml

although a standard 4 pin fan would need the connector rewired to work
http://pinouts.ru/Motherboard/mb_pwm_fan.shtml

 

[kapalua12]

Thanks for the info.

What do you think about the Noctua brand fans? The color is ugly but it won't show inside my case anyway: Here at Amazon:

http://www.amazon.com/gp/product/B00...pf_rd_i=507846

 

[dawp]

noctua is generally considered a quality manufacturer.