Fan orientation options with Antec 900, i7, and Noctua NH-U12P SE1366.

[anindrew]

Hi all! I've been enjoying my new i7 920 system for the past month and a half. I have it in an Antec 900 case. Right now, I have the CPU cooler setup in a push-pull system with two fans that line up perfectly with the 900's exhaust fan. Add in the fact that I have one of the drive cage fans on the top and I think I have some nice cooling.

Since I am overclocking the system a bit (and wouldn't mind getting a bit more out of it), I am wondering about a couple other options. The Antec 900 has that huge 200mm fan on the top as an exhaust fan. I could turn my CPU cooler 90 degrees and exhaust the air straight up into the 200mm fan and out of the case. Do you think that would make an impact on temperatures at all? I could also flip the 120mm exhaust fan on the back and make it suck in cool air to blow onto the side of the CPU cooler if I did that setup.

Another option I am considering is to flip the top 200mm fan over so that it blows air into the case right onto the CPU area. I can picture that causing temperatures to drop a bit. I imagine it's a bit of work to flip that fan, but I found detailed instructions online along with diagrams. What do you think of doing that?

Thanks to everyone for their help and advice.

 

[imported_wired247]

heat rises, so keep the exhaust fan pointing up.

given your current orientation I would not think rotating by 90 degrees would change your temps by much.

keep the rear fan pointing outward as well. intake fans should be in the front and lower than the exhaust fans. heat rises off the video card and CPU. the top fan and rear exhaust fan help with this.

I honestly wouldn't change anything at all. sounds like you might have too many fans as it is. remember that fans generate heat. calculate how many watts they are using... then imagine a little light bulb inside your case generating that much heat.

obviously it's not exactly the same thing. But "more fans" has never and will never equal "better cooling".

 

[anindrew]

Thank you very much for the reply, wired247. Just out of curiosity, I flipped the 200mm fan around to see if there was any difference. To be honest, I don't think there was one. And since heat rises, having that fan blowing downward caused my system temps to be a little higher. I flipped the fan back to the normal "exhaust" position. You were right, sir, the way I had it was the best. And to anyone who may consider flipping the 200mm fan in their Antec 900, it is a royal waste of time. I need to learn to leave well and well enough alone!

I don't think I'm using too many fans. I'm only using the ones that came stock in the case plus the two that came with the CPU cooler. My system and CPU temperatures stay about the same around 30 degrees C.

 

[tviceman]

I have to revive this topic because I've been trying to find the answer to the original question on this thread without any certainty. I had to RMA my motherboard (the onboard sound and LAN quit working) so I'll have a great opportunity to potentially maximize the cooling capabilities of my Antec 900 case. With the big boy 200mm fan exhaust on the top pulling air out of the case, would it make sense to orient the CPU fan to blow towards the 200mm exhaust? Physics tells me yes, yet I've yet to see any results from others who may have tried this. I've had my cpu fan blowing towards the 120mm fan in the BACK of the case up until I disassembled everything, and since most fans require the motherboard out of the case for installation (at least for working space), I'd like to get it right on the first try.

So, orient the CPU fan to blow towards the top of the case where the 200mm fan works, or towards the back where the 120mm fan works?

 

[zagood]

The top blowhole works better as a pure exhaust. Remember, you also need to exhaust the rest of the case air, not just the air going through the CPU heatsink. So no, in general the best orientation will be the CPu heatsink blowing out the back.

Addendum - all individual cases are different because of different components. If you have the time, it's always worth trying new things (if only to prove yourself or someone else wrong).

-z

 

[jandlecack]

I've got a Coolermaster CM690 which is very similar to your case and the same heatsink as you do (it's great).

My ventilation consists of 6 Silverstone Suscool Ultra Quiet fans running at ~900RPM 21db, which I can live with. Otherwise, when I set stock or mild overclocks, I run the fans at 70% capacity which makes them nigh silent.

They are laid out as follows: 1x rear blowing outward, 2x top blowing outward, 1x bottom blowing inward, 1x side (lower) blowing inward, and I have one Coolermaster LED fan in front which doesn't really do a lot but looks good. The front fan I've found out by testing doesn't change my temps noticeably. But I wouldn't remove it either.

The optimal heat dissipation takes place at the rear and top location of your case, and the airflow should begin in the front and end in the back. This is complimented by strong exhaust and intake fans, which is why I use the bottom and side fans for intake. They help push the hot air out of the case. I also have oriented the CPU heatsink in push-pull to blow the air out of the rear, not the top. This is because often the x58 motherboards rely on your CPU fan to help cool the RAM DIMMs. With my Rampage II extreme it is explicitly stated that if using a passive heatsink (no fan attached), you must install the optional motherboard fan that was included in the bundle.

At these settings, with a Vcore of 1.25 (no LLC) and QPI of 1.25, I run my system at 3.8GHZ most of the time, and 4GHZ with a slight voltage bump + turbo mode if I need to squeeze out the extra juice. Pretty sure I could go farther but there isn't any need yet.

With above mentioned settings I get the following temperatures in Linx under 1.5GB testing load:

Maximum #0 66C #1 64C #2 65C #3 61C
Average #0 65C #1 62C #2 64C #3 61C

Idle to minor load (surfing, office tasks):

Average #0 39 #1 34C #2 38C #3 34C
Minimum #0 37C #1 33C #2 36C #3 32C

I'd also like to mention that good cooling starts with good thermal paste, applying procedure, and heatsink seating. If you need advice on the latter two let me know, but I didn't think you did.

 

[43st]

Point it up!! Always try to work with convection, it's a stronger force than most realize. When I was using a 900 I used two methods, with un-overclocked chips. One was just the CPU fan pointing up, thru the heatsink, and no 200mm. And the other was 200mm only, with no CPU fan. Both worked well through the winter (with Zigmatek S1283).

I recently moved on to an Antec 300, still using same method but with both fans on low.

 

[tviceman]

I'm getting conflicting responses! Maybe I should have provided a little more information. I have three 120mm intake fans, two on the front bottom half of my case and another on the side window blowing on my video card (GTX 260). I've got two exhaust fans, a 120mm in the rear side of my case parallel to my CPU, and a 200mm exhaust on the of the case. I'm using a Zalman 9500 heatsink/fan to cool my CPU. I can either point the zalman 9500 to the back of my case towards the rear 120mm exhaust, or I can point it up towards the 200mm exhaust. I've been pointing it towards the rear 120mm exhaust (with great results, but I value quietness as much as cooling and my cpu heatsink/fan isn't exactly quiet when turned up), but since I'm getting conflicting answers I might as well experiment and try pointing it up. It will be a few weeks but I will post my results/thoughts!

 

[tviceman]

And thank you all for the input so far!

 

[jandlecack]

Sorry, I was talking to the OP actually.

In your case, it sounds pretty good. If you definitely want to make sure what suits your needs best, try the different orientation topwards. Personally I prefer the cooler to dissipate the heat out of the rear, as the rear fan in my case is closer to the pull-fan of my CPU than the top fan is. Plus, on both top fans, I have noticed that the air coming out isn't even warm most of the time. Might be the mesh though, it doesn't let air through as well as it should.

Forgot to mention: WIRE MANAGEMENT.

It is essential to good cooling. Try to route cables behind your motherboard tray as much as possible.

Mine:
http://img152.imageshack.us/img152/4065/dsc00040w.jpg
http://img139.imageshack.us/img139/6026/dsc00039gwz.jpg

Can't really see all the cabling but you get the idea. Especially the CPU 8-pin is often in the way of the airflow. Get that back there.

Also place your HDDs in the bottom most positions.

 

[tviceman]

I've modded my case when I got it to run as many cables as possible behind the motherboard tray.

http://i83.photobucket.com/alb...m%20Stuff/IMG_0778.gif

The sparkling stars are the spots where I drilled holes to route the cables through. I'll be sure to update this thread in the coming weeks when I get my motherboard back from ASUS and piece it back together.

 

[jandlecack]

That's pretty neat.

 

[tviceman]

For those interested, I wanted to send out a quick update on my experiment. I got my asus motherboard back from repair, and unfortunately they did not repair any of the issues it is having. They are advanced shipping me a new motherboard and allowing me to hold onto my current one until the new one arrives (and works). In the meantime, I upgraded my CPU fan/heatsink to the Noctua NH-U12P, like the original poster has, but not in the push pull setup. Even with just 1 fan, it's performance is world class vs. the zalman cnp-9500 I previously had. The 9500 was very noisy with the fan turned up all the way, wheres the noctua cannot be heard from normal sitting distance. Also, and most importantly, the noctua cools considerably better. My core temp readings are consistently 3-4 degrees celsius cooler when idle, and 7-8 degrees cooler under load!

I encountered a snag though when installing the fan to point towards the top of the case. I have a side-window fan blowing on my GPU that bumped up against the noctua (didn't have this problem with the old heatsink/fan). I had to saw off a corner of the side window fan to get everything to fit, but in the process reinstalled the noctua to face towards the back because I was slightly frustrated and didn't want to have to deal with it any longer LOL.

When my new board comes I will, once again, try orient the fan to blow up towards the 140mm and let you all know of how it's cooling now vs. pointing the cpu heatsink/fan up.

 

[tviceman]

Any help would be appreciated:

http://forums.anandtech.com/me...=2304357&enterthread=y

 

[BonzaiDuck]

Originally posted by: tviceman
Any help would be appreciated:

http://forums.anandtech.com/me...=2304357&enterthread=y

Nobody has "dissed" me on this yet. I think the Antec 900 has plenty of room in it, so no problem there.

Fan orientation -- or even the number of fans -- is not a big issue if:

1) You use large, high-CFM/low-rpm fans for intake
2) The intake CFM is more or less greater than the exhaust
3) You duct the motherboard so that the case intake air is forced through a narrow volume above the memory, chipset and motherboard to exhaust the air immediately through an exhaust fan
4) You can also duct the Noctua, although cooling improvements from the ducting are not as great for efficient heatpipe coolers such as the Noctua. However, if possible, duct the Noctua exhaust-side to an exhaust fan.

You can use foam-art-board to construct the ducts. It's tedious, but there is a margin of improvement.

 

[rgallant]

-Just to add to the posting

-as with jandlecack , I have a cm690
-I modded the case by removing all sheet metal from the fan mounts .
-running a very hot 780i which runs cool @ 53c after adding a 80x80x15mm fan that the 690 mounts behind the mother board [drops 3-5c] . plus-the Noctua is push-pull going up , why - sucks air from the hot nb - plus the hit pipes seemed to make more sense to run them flat to me, if there's any water in them.
-I run more cfm's in , than out- as gtx285 sli blows alot of air out of the case and I do not not want them lacking air.
-2x 140mm , 1x120mm ,1x 80mm in -3x120mm out
-power supply gets the air from bottom-outside air , not case air so it dose not count in the in -out - air balance.
-but for those with the 900 , I would think with the power suppy pulling air out of your case , you should have alot more intake cfms -than what you might think is needed.
-I have a heat probe in the the Noctua fins and it never shows air over 27-28c -rooms at 24c at this time ,and cpu @4.3
-all the intake fans have custom high flow dust filters on them. also why the high cfm's in.
-also to note :the only 140mm fans I can find like the Yate loon , all have crap sleeve bearings , that do not like running facing down , so the one in the bottom runs @ 1150rpm -switch it with the same fan on the side and it runs @1350rpm on the side[filters not on ] so for the top I still just use the Nochua's 120mm x2 for now.

 

[BonzaiDuck]

Originally posted by: rgallant
-Just to add to the posting

-as with jandlecack , I have a cm690
-I modded the case by removing all sheet metal from the fan mounts .
-running a very hot 780i which runs cool @ 53c after adding a 80x80x15mm fan that the 690 mounts behind the mother board [drops 3-5c] . plus-the Noctua is push-pull going up , why - sucks air from the hot nb - plus the hit pipes seemed to make more sense to run them flat to me, if there's any water in them.
-I run more cfm's in , than out- as gtx285 sli blows alot of air out of the case and I do not not want them lacking air.
-2x 140mm , 1x120mm ,1x 80mm in -3x120mm out
-power supply gets the air from bottom-outside air , not case air so it dose not count in the in -out - air balance.
-but for those with the 900 , I would think with the power suppy pulling air out of your case , you should have alot more intake cfms -than what you might think is needed.
-I have a heat probe in the the Noctua fins and it never shows air over 27-28c -rooms at 24c at this time ,and cpu @4.3
-all the intake fans have custom high flow dust filters on them. also why the high cfm's in.
-also to note :the only 140mm fans I can find like the Yate loon , all have crap sleeve bearings , that do not like running facing down , so the one in the bottom runs @ 1150rpm -switch it with the same fan on the side and it runs @1350rpm on the side[filters not on ] so for the top I still just use the Nochua's 120mm x2 for now.

Is this answer to my last post? EDIT: the more I look at your remarks, the less it seems as though you're asking me a question. I'll just leave my original material below -- FYI to other forum members.

Pressurized case with IntakeCFM > ExhaustCFM works this way. Pressurized means greater density. Greater density means more thermal dissipation, if the pressurized air is forced through apertures in a ducting arrangement that restricts the flow somewhat. The rest of it just involves exhausting air directly after it has passed over the hottest components.

With air channeled this way, you can deploy a minimum of exhaust fans and reduce the number of intake fans to overtake exhaust CFM. But ducting the hot parts is critical. If done this way, case interior (duct exterior) air remains cool, and the hot components stay cooler. I believe you could even use this method to enhance a watercooling setup. For one thing, it might make enough difference to dispense with using a chipset waterblock, or even a graphics card waterblock. Temperatures for those components may be higher than in a WC setup, but lower than "regular" air-cooling, and no problem at all such as you'd face with case interior heating up because of hot graphics cards. All of the warmed-over air gets exhausted before that happens.

 

[stuckinasquare3]

Something I like to do when its a little cold out is open the window just wide enough to match the case width. I have an Antec 900 on my desk and I flip it around so that the front points toward the window. It's not the prettiest thing to look at but when those fans suck in the cold air from outside it can really cool down your temps.