Antec 900, Do I need extra fans?

[B_corazzini]

Im about to buy another 660 ti to Sli. Having 2 gpus is gonna create more heat so should I get extra fans for the optional side window and middle fan inside the case? The antec 900 already has 2 front intake fans and 2 top and rear exhaust fans.

 

[Raiddinn]

You don't have to get more, but its almost always better if you do.

The side fan, in particular, usually makes more of a difference in cooling than any other fan in the case.

If you can fit 1 extra in and 1 extra out, its probably a good idea that you do.

 

[B_corazzini]

I think I might get just 1 intake fan for the side, that way air will be blowing right on the gpus but I heard that having a side fan can disrupt airflow and actually raise temps in the computer, is this true?

 

[Raiddinn]

Not sure where you read that, but side fans rarely disrupt anything in a good case.

That being said, its helpful to have negative pressure when possible, failing that to have neutral pressure, and least ideally positive pressure.

Negative pressure = more out than in
Neutral pressure = equal in/out
Positive pressure = more in than out

Right now you are sitting on negative, but if you just throw a side fan on you are almost certain to be in the positive pressure zone or neutral at the best. Throwing an extra out on in addition to the extra in would allow you to stay in the negative space which is where you ideally want to be at.

Temperature wise, the side fan would be better on than off even without the extra exhaust fan, but it does create some other sorts of problems that are not ideal in terms of airflow.

I used to have a really good link that tested every possible configuration up to like 6 fans, but I lost it and can't find it again. I do have two general cooling links that I can throw up, but they are less useful than the one I can't find.

The links are below if you are interested:

http://tinyurl.com/8hwz4td
http://tinyurl.com/cgx3zoy

 

[nukemaster]

I think the 900 will be just fine with stock fans. I had one for years.

That 200mm top pushes so much air out that air will gets sucked in from the other vents anyway

I actually ran a 900 with the front fans out to make it more quiet. While the hard drives did get a bit warmer, the overall system temps did not move.

The side fan sometimes gets in the way of cpu coolers as well so watch out or be ready to mod a bit.

Fits right in

 

[B_corazzini]

Yeah I'm kind of worried that I might need to do some modding for the side fan since the Evo is so big lol But I think I should be fine.

 

[nukemaster]

My heatsink(CNPS10X Flex) was facing up(wanted to take advantage of the top fan pulling air up), so that's more the reason why i had that issue.

 

[B_corazzini]

Best answer selected by B_corazzini.

 

[B_corazzini]

Do you guys think i will need a low profile fan since my cpu fan (evo) might get in the way since its facing up? What low profile fan do you guys reccomend?

 

[nukemaster]

I would use the slipstream slim as its the only thing that would fit, but chances are you will not need the side fan.

http://www.scythe-eu.com/en/products/fans/slip-stream-120-mm-slim.html
The 1200rpm one is very quiet but does not move lots of air(the 1600 may be a better option). Interesting enough, I have used it as a cpu fan without issues

Sometimes you just want to fit a heatsink AND hard drive. The same fan with a CNPS10X Flex was able to keep a I7 920 under control too, not as good as a 25mm thick fan, but you know.

Your motherboards cpu socket location also has an effect. Some sockets are high enough to avoid hitting all together.

 

[Raiddinn]

That picture literally terrifies me. I am not even joking. I am not the kinda person to cry a lot, but that gets me pretty close.

The slipstream fan probably doesn't move a lot of air because it can't even find any air to intake.

I would be surprised if that PC lasted more than a month with everything installed and the sides on.

I should save that picture and use it as an example of the worst possible setup for airflow. I had some pretty bad airflow in the past, but that case/fan setup looks godly compared to this one.

Looks like a poster child for what not to do to me.

 

[nukemaster]

It does not move lots of air because it is rated at 24.03 cfm.

2 years + 24/7 operation and going without any issues. Just in case you did not see, the fan blows air right into the power supply(and still about a 10mm gap from one another), so it has NO issues with moving air. It even "cools" the hard drive.

With core temps in the low 30s' not much over 50 after hours of gaming. I would not say this system would die in a month.

Scythe sells those fans for hard drive cooling as well So they are MADE to be very close without much loss in performance.

I also later swapped put the power supply fan for something quieter(and now i can monitor its speed) and cut out the fan grille for better air flow. Still want to cry?

I got a single hard drive(2 was louder then I liked) later and filed a 120mm x 25mm fan to be thin enough to fit.

Did i mention that I re drilled the cooler bracket to move it over just a that little bit to clear the video card.

Just because you can not see how things work in the real world is no reason to call something "an example of the worst possible setup for airflow". The air flow is MORE then enough and the setup tweaked to give the best temps and quiet operation in a SFF system.

Again, you are entitled to your opinion.

 

[B_corazzini]

I went with a scythe slipstream 1200 rpm last night. didnt want something too loud. It should help cool the gpu a little bit right?

 

[Raiddinn]

Just because something works in practice doesn't make it not "an example of the worst possible setup for airflow".

A lot of SFFs do OK, but they all pretty much disregard every airflow best practice there is.

I can see how such a setup might work, but I just can't see why anyone should try to make it work. Getting my head around the convoluted path air is supposed to take on its way through there is more difficult.

Maybe you don't worry every minute about the status of your components in that case, but if that was my PC I would be worrying about it constantly.

I think in my case something well north of 90% is empty space and that is a whole lot closer to ideal than a figure that is in the low single digits %.

 

[nukemaster]

I went with a scythe slipstream 1200 rpm last night. didnt want something too loud. It should help cool the gpu a little bit right?

It can't hurt .

@ Raiddinn

If I had not tested it in another case(Antec 900. Guess what over 90% empty space with that little system) and got the same temperatures? It is worlds ahead of ANY system with stock cooling. It also ran prime95 for 3 weeks to ensure it was stable when setup.

90%+ empty space huh? That makes sense. I guess big cases do look more impressive don't that.

I think you are just trying to sound smart. Have a good day sir.

 

[Raiddinn]

Cases looking impressive - I don't really know, my case certainly isn't designed for show. Whatever part of it is designed for show I am not using because I rarely look at it and never actually show it to anyone.

Saying that empty space is good for airflow, however, doesn't make me sound smart, it makes me sound like I have some idea what is going on.

I am not saying 90% is ideal, but its a whole lot closer to ideal than 2% is.

 

[Uther39]

Not sure where you read that, but side fans rarely disrupt anything in a good case.

That being said, its helpful to have negative pressure when possible, failing that to have neutral pressure, and least ideally positive pressure.

Negative pressure = more out than in
Neutral pressure = equal in/out
Positive pressure = more in than out

Right now you are sitting on negative, but if you just throw a side fan on you are almost certain to be in the positive pressure zone or neutral at the best. Throwing an extra out on in addition to the extra in would allow you to stay in the negative space which is where you ideally want to be at.

Temperature wise, the side fan would be better on than off even without the extra exhaust fan, but it does create some other sorts of problems that are not ideal in terms of airflow.

I used to have a really good link that tested every possible configuration up to like 6 fans, but I lost it and can't find it again. I do have two general cooling links that I can throw up, but they are less useful than the one I can't find.

The links are below if you are interested:

http://tinyurl.com/8hwz4td
http://tinyurl.com/cgx3zoy

That statement right there is a load of rubbish, its widely known and regarded that having Positive air pressure in a case is not only more beneficial for keeping the inside of your case dust free and clean(so long as all intakes are filtered) but also gives the internal components the better cooling solution. Lets face it most modern day case manufacturers design there cases to have positive air pressure, just look at the likes of Silverstone.

http://www.silverstonetek.com/techtalk_cont.php?tid=wh_positive&area=usa
http://www.youtube.com/watch?v=6UWob9KyaB4

 

[Raiddinn]

I agree, we should all look at completely one sided discussions from companies just trying to sell their products that don't even go into detail about the most major considerations (effects on temperatures).

Certainly it is much better to do that than to look at articles written by people not trying to sell anything who go into both the pros and cons of each kind of setup.

Good idea. Let's all do that.

 

[Uther39]

OK then if you wish to totally ignore everything any body half decent has too say, i notice you made no mention of the independent opinion on the youtube video by some one who is highly respected.

So ok i will also disregard all of that and instead go with 12 years of experience in the IT hardware industry in both building and repairing systems, and i can tell you dear OP, that Positive Air pressure is by far the best way to go when wanting a clean and cool environment for your cases internal components.

I do find it strange however that Raiddinn thinks that most modern day Case manufacturers would waist all that money on R&D just to sell us something that does not work in his opinion, when they could just of easily gone with negative or neutral air pressure, hmmmm strange indeed.

Now be real Raiddinn.

 

[Raiddinn]

The main tradeoff is dust vs temperatures.

Is less dust worth it to you if it means higher temperatures? How about more dust and you get lower temperatures?

Silverstone obviously chooses the former, I obviously choose the latter.

Positive pressure brings in more air through "hopefully" dust filtered intakes which ideally should mean that less dust makes it into the case. It is not clear, though, that hot air can easily escape easily from this environment. With positive pressure all the air wants to get out including the cold air that just came in. Cold air fights with warm air about which gets to go out of the case.

With negative pressure, you have more air coming in through unfiltered places. However, the hot air doesn't have to fight with cold air about which one gets to get out of the case.

That does mean that the PC will have to be cleaned out once in a while, more often the more negative the pressure is, but it also leads to hot air getting out more easily and therefore lower temperatures.

As with most things you can't get the best of both worlds, there are tradeoffs involved. It just depends on which bad thing you want to tolerate in order to get which good thing.

Even your Youtube Video says the same thing, although it comes to a different conclusion about which is "better" and the conclusion reached in the Youtube video has absolutely nothing to do with lower temperatures.

In fact, nowhere in either - edit one of Uther's - link did I see where it said positive pressure leads to lower temperatures than negative ones and at least one time one of the links says the exact opposite.

Your links are, however, completely worthless because they just rehash what my links said long before you showed up.