Ducting an 80mm fan to 120mm Hyper212 fan, advice?

[wicke038]

Turns out 2x5.25" bays are the perfect height for an 80mm fan. Measured 8 holes in each side on the top and bottom of the respective bay covers, drilled holes large enough for the fan screws, bent a bit of metal in the middle so the fan would sit flat, and mounted the fan to the bay doors with a grill on the outside, then attached an 80mm air duct to the fan inside the case to pump cool air to the CPU.

The core temperature is so low that it will not register with the faulty temperature core sensors that plagues the Wolfdale chips. Running Prime95 to generate maximum heat, the CPU doesn't budge above 38C (100F), and idles at 24C. Temperatures for both cores read 41C idle or under load (and yes, they do register temperatures above 41C, given the opportunity).

In pictures:

 

[wicke038]

OK, I'm thinking of getting a 80mm to 120mm adapter to attach the duct to the Hyper 212. 80mm blows 35CFM, and the 120MM on the Hyper 212 blows 70CFM. Should I duct the 80mm to the 120mm?

 

[wicke038]

I thought I'd retitle the thread instead of posting an entire new one...

Is it a good idea to duct the 120mm fan on my Hyper212 to the 80mm fan with duct I built? The 80mm blows 35CFM, the 120MM fan 70CPM. So good idea, yay or nay?

 

[rubix_1011]

It might help a little, but you'd be better off addressing the issue differently. Poor airflow in an Antec 900? I didn't know that was possible.

 

[wicke038]

It might help a little, but you'd be better off addressing the issue differently. Poor airflow in an Antec 900? I didn't know that was possible.

I'm already getting 22C CPU idle, 38C CPU under load (with faulty temp sensors on the Wolfdales the e8400 never breaks 41C on the cores). I'd just like it to be a little cooler under load.

 

[rubix_1011]

So, how do you know for sure what your temps are? And 38C under load (depending how accurate those temps are) is pretty good, although I question them being valid...that's about what my watercooled, OC (3.4ghz) Q6600 runs at idle...so either you have very low ambient temps or you have some kind of magical heatsink.

 

[wicke038]

So, how do you know for sure what your temps are? And 38C under load (depending how accurate those temps are) is pretty good, although I question them being valid...that's about what my watercooled, OC (3.4ghz) Q6600 runs at idle...so either you have very low ambient temps or you have some kind of magical heatsink.

Magical indeed, Cooler Master Hyper 212 Pro. Ambient temperature is about 63F. Speedfan registers my case (mobo?) temp as 22C as well. I'm not sure what the core temps are. I have every reason to believe they are less than 41C under 100% load. With the Arctic Freezer Pro my temps were 41C idle and 48C load for the e8400.

As said before, there's a temperature sensor fault with the Wolfdale chips that make it so they cannot read temps below a certain level (varies from chip to chip). The lower limit of the sensors on my chip is 41C.

Anandtech achieved 25C idle, 36C at 100% load:
http://www.anandtech.com/show/2366/4

Frostytech, 12C above ambient:
http://www.frostytech.com/articleview.cfm?articleID=2206

My results are at the very low-end of what's typical for the Hyper212. My ambient temps are probably cooler than about 90% of the people using this cooler though.

I'm just wondering though whether the physics are feasible in ducting the 70CFM 120mm fan on the Hyper 212 to the 35CFM 80MM fan on the front of the case. I.E., will their be turbulence, am I going to choke the 120mm fan of the air that it needs, should I remove the 80MM fan and just have a straight air tunnel to the Hyper 212, etc.

 

[nukemaster]

I would just leave it like that. So the cpu fan gets cooler front air, and if it needs more, it can pull from the rest of the case air.

If you duct it to the cpu fan, the cpu fan will have to work harder to pull air from the slower 80mm fan(and the restrictive 80mm tube). It may even start to spin the 80mm on its own from the suction

 

[wicke038]

So basically just leave the duct as-is as a cold air intake. Pretty solid advice, actually, thinking about it that way.

 

[mattimeo005]

What's your reason for wanting even lower core temps? 38C under load is ridiculously cool under air, and there are no benefits from going even lower than that.

Anyways, to answer your question, forcing 70CFM through a 35CFM fan probably isn't going to be very friendly on your fan, so my gut feeling would be to not do that, as it will severely shorten the life of the fan.

 

[wicke038]

What's your reason for wanting even lower core temps? 38C under load is ridiculously cool under air, and there are no benefits from going even lower than that.

The e8400 is currently OC'ed to 3.6GHz. I'd like to push it to 4.2GHz.

 

[d1rtyju1c3]

You should have no problem. At least I didn't. I had mine OC'ed to 4.2ghz on air and 4.7ghz with extreme water cooling and could have gone higher.(reservoir and pump was in a phase change style mini fridge with the freezer section removed and sitting in the reservoir). Dont recommend unless you have the right protection for condensation (I fried 2 XFX 790i boards and I was lucky I didnt fry anything else). But it was extremely fun for a couple of months until I couldnt afford to do it any more plus my wife was going to kill me. :lol:
So I just upgraded. :lol:

 

[d1rtyju1c3]

Anyway, you should easily hit a stable 24/7 4.2ghz on air. [:bohleyk:1]

 

[d1rtyju1c3]

My cores were stuck at 38c Idle but would rise above that under load but it would take a while. That is the only complaint I have about that CPU. I would have liked to known my Idle temps.

 

[wicke038]

Anyway, you should easily hit a stable 24/7 4.2ghz on air. [:bohleyk:1]

Any recommendations on voltage? I'm currently at 1.18625 at 3.6GHz.

 

[d1rtyju1c3]

I have to try and remember.




I was running 4ghz at 1.3v-1.32v vcore, so you might try 1.35v and go from there. If it works try lowering voltage if not try raising voltage. Also might have to raise FSB voltage. I would start at 1.2v and go from there. Try to keep memory as close to native frequency as possible.

Sorry I cant give you the exact settings It has been awhile since I have messed with that CPU and I never saved any screen shots.

You will probably have to play with voltages a bit but its worth the time.

 

[Aquire_assisstance]

I am thinking of doing the same thing with my storm enforcer. Only with a 120mm fan that can clip right in to those drive bays. I'm just wondering, what material did you use for that cold air intake duct? Where did you get it? i dont want to put metal in my case and your seems like it's plastic.