What is the difference in where the PSU fan is located

[BloodTotal]

What kind of difference does it make where the PSU fan is located. Since the fact that Antec 900 cases have the PSU on the bottom, then you would have to flip the 120mm PSUs upside down.

The OCZ 1010W with 120mm fan

http://images10.newegg.com/NeweggImage/productimage/17-341-007-09.jpg

The OCZ 1000W with 80mm fan

http://images10.newegg.com/NeweggImage/productimage/17-341-006-10.jpg

[Kursah]

I would go for the larger fan...I got a suprise late x-mas present. I now have an Antec900 due to my family and g/f pitching in after I went broke on a family related situation. I was going to buy Fitseries 900, and if my family would've asked me more I would've had them get it from him because they paid waayyy too much for the case locally lol.

I use a Corsiar HX520 with a fan placement similar to the first PSU you listed, yeah it sites upside down, sucking air from the bottom of the case, but the fan is silent, keeps the PSU very cool. It has mounting holes for either directions, and rubber pads to keep the PSU off the bottom of the frame, but moutning it with the fan down will require a hole be cut for proper air-flow. I have had no issues with my PSU, granted I've only had my setup for a few days...but no issues at all.

Look up antec 900 in Cases and Modding section, you'll see a few pics that'll show you how it'll look.

:toast:

[erocker]

There are two different options because if you're running SLi, it would be better to have the fan in front instead of on top for airflow reasons.

[BloodTotal]

There are two different options because if you're running SLi, it would be better to have the fan in front instead of on top for airflow reasons.

what do you mean, there is a possibility I will be running SLI, what would be the difference?

[keakar]

What kind of difference does it make where the PSU fan is located. Since the fact that Antec 900 cases have the PSU on the bottom, then you would have to flip the 120mm PSUs upside down.



no, the case is made so you mount the psu upside down so the fan faces up. you can still mount it down by cutting out the bottom of the floorpan but it is not the best way because it can restrict airflow or block it altogether if sitting on carpet.

[cdawall]

all of mine have had either the one just on the bottom or both a 120mm on the bottom adna 80mm out the back either way its stays cool.

wait thank you bloodtotal i just remebered i have a 120mm fan sitting in one of my PSUs in the garage! ha now i only have to buy one :D

[Ben Clarke]

If the fan is on the underside of the PSU, and the fan is at the bottom, as long as you have some space under the case (e.g. some stands) you can cut a grille. Alternatively, you can just leave it as it is, as air usually comes out the back anyway.

[BloodTotal]

no, the case is made so you mount the psu upside down so the fan faces up. you can still mount it down by cutting out the bottom of the floorpan but it is not the best way because it can restrict airflow or block it altogether if sitting on carpet.

obviously you wouldnt put the PSU with a 120mm down to completely block airflow, what im concerned about is which would be better for airflow if mounted properly. Im coming to the conclusion that the 120mm is better by googling.

[panchoman]

In my opinion(and the opinion of a few top notch psu manufactureres)

a single 80 mm fan on the back by the power switch(like with the second ocz) is more effective then a single 120mm fan on the bottom of the psu (like with the 1st ocz) in the 80mm design, it cools the tops of the components, whereas the 120mm design will cool the back of the components. for example, using computer cases as a parallel,the 80mm design is like your standard fans, in the front top and back of the case. the air cools the tops of the components. the 120mm psu fan design is like sticking a fan behind your motherboard. sure it'll cool, but the airflow is going to be crap and its not going to be very effective. you're cooling the back of the motherboard with a bigger fan, but you wont be cooling the components on top of the mainboard(like the pci cards, chipset, cpu, etc.) very effectively will you? this same idea applies to the psu, the 120mm cools the back of the psu's "mainboard" whereas the 80mm design cools the tops of the components. bigger is not always better.

edit: also, with the 120mm design, you're running the air right into your psu's mainboard, and it cant escape very well, causing airflow issues. whereas with a 80mm design, the fan will push air through your psu and out the vents directly on the opposite site.

[BloodTotal]

In my opinion(and the opinion of a few top notch psu manufactureres)

a single 80 mm fan on the back by the power switch(like with the second ocz) is more effective then a single 120mm fan on the bottom of the psu (like with the 1st ocz) in the 80mm design, it cools the tops of the components, whereas the 120mm design will cool the back of the components. for example, using computer cases as a parallel,the 80mm design is like your standard fans, in the front top and back of the case. the air cools the tops of the components. the 120mm psu fan design is like sticking a fan behind your motherboard. sure it'll cool, but the airflow is going to be crap and its not going to be very effective. you're cooling the back of the motherboard with a bigger fan, but you wont be cooling the components on top of the mainboard(like the pci cards, chipset, cpu, etc.) very effectively will you? this same idea applies to the psu, the 120mm cools the back of the psu's "mainboard" whereas the 80mm design cools the tops of the components. bigger is not always better.

edit: also, with the 120mm design, you're running the air right into your psu's mainboard, and it cant escape very well, causing airflow issues. whereas with a 80mm design, the fan will push air through your psu and out the vents directly on the opposite site.

been googling alot here and the opinions of people and companies vary and are biased for the companies. Noise , for the 1000W with a 80mm fan goes to 60dba and most of the power supplies usually go around 50dba.

will it be a big difference between an 80mm and a 120mm, what kind of performance boost/cooling boost would it be for the 80mm in relation to a 120mm

[tkpenalty]

You guys ALL forgot one crucial issue with the fan at the top, first off, remember that 24 pin cable strand, remember where it is! If you have the PSU inverted that cable strand is towards the outside of the case. Not so nice for cable management... Both PSU fan designs either way, I wouldn't really worry. A push and pull fan system is as effective as a single blowing fan.