CPU duct in the back of the motherboard

ADVISE perhaps the temps reported are wrong because the temp drop is of about 12°C, so I will have to look for an extra thermistor connected to a circuit im making.

I just made a new invention, a duct in the back of the case, which narrows the air flow of my old stock amd fan to a 6cm long x 2cm wide area that blows to a whole that lies just behind the cpu socket, so actually it blows to the area of the soldering points of the socket pins and the middle of the undercore space.

My temps were around 35c for the case, and 44c idle 54c full load, this is with the fan at max speed and case covers off, otherwise it is 47-48c/55c. Now the temps are at 30c for the case, 36c idle, 41c full load with the volcano at max speed, at slowest speed it is 42-43c full load.

Some people might say that the air is influencing directly on the thermistor that lies between the space that is in the middle of the cpu socket, touching the cpu underneath where the die center is, but my opinion is that the only part of the thermistor that actually works a variable resistance due to heat are no more than 1-2 mm in the top of the curved yellow plastic, so the temps are not supposed to be altered because this part is always in touch with the cpu die.

I am really happy with this thing, because I got temp drops of around 12c and now I am ready to overclock this baby, in the future I am going to tie up the thing better and then change the fan for a blower with a little duct like this one also, and open a hole for it with a dremel on the case door.

I am gonna attach some pics in a while, wait for them.

No one wants to answer? heh, has someone done this thing before? Pics will be up by tomorrow afternoon

just waiting for pics

if its a fan blowing on the back of the socket, ur most likely cooling the socket more than the cpu, wich is y the temps are so much lower. im not saying it doesnt cool the cpu at all, but it just cools the socket more than the cpu.

sounds pertty intresting , cant wait to see the pics

it's been done also want pics, i've been wanting to do it myself for a while (hopefully cooling mosfets)

I just did a very similar thing yesterday to a Chieftec steel case. I marked the spot on the motherboard mounting plate where the cpu would go and drilled a small hole all the way through, including the right side panel. This marked the center spot on the side panel, as well as the mobo mounting plate. I then used a hole saw on a hand held drill and cut a 83mm hole through the motherboard mounting plate and a 92mm hole on the right side panel. After some clean up with a rotary tool I took a 16 oz Arrow brand plastic party cup and cut it to make a duct. The lip of the cup fits perfectly on the 92mm side and it tapers as it gets to the bottom. I cut the top inch and slit it and test fitted it (the slit allows for adjustment to the narrower motherboard side) and cut off the excess so that the duct just barely stuck through the hole cut out from the mobo mounting plate. I now have a 92mm fan mounted on the right side panel blowing cool air in, ducted directly to the back of the socket. The rig is under construction therefore I will never know what the temperatures would have been without this backside cooling, however I'm quite sure that it doesn't hurt my cooling efforts and it was pretty easy to do. The plastic cup was perfect for this short (about 1/2 inch) duct and it is held in place by the fan on one side and it just long enough to rest inside the 83mm hole I cut in the mobo mounting plate. It (the duct) will come out with the side panel anytime it is removed. If it (the duct) breaks, I'll just have a drink of water and make another one from my cup

Another benefit was getting rid of some steel. It is truly amazing just how heavy a 3 1/2 inch round piece of Chieftec case is. It made me wonder if/why I couldn't cut a bunch of 1 inch holes in the mobo mounting plate in order to lighten up the case. I used to do that king of stuff to motorcycle chainguards and the like to cut out excess weight (every ounce counts when you're going for those low E.T.s). Does anyone know of any reason why I wouldn't want to do this in future builds? I have access to a drill press so I think I could do it pretty easy to do. All I have to do is to make sure that I don't cut out the holes used for mounting the various size motherboards and that's only to preserve the flexibility of the case to handle a variety of motherboards.

Yeah, sorry for the pics things but im waiting for my server.

It cools the socket, soldering points and pcb which are also a way for the cpu heat to dissipate, the most of it goes to the hs because of the low resistance, but plenty of it goes to the pcb and soldering points also. Its always nice to take away the heat from every part of the pc heh.

Does it look something like this..

Aye aye, but with a fan blowing to the hole, and the hole is many times smaller so the duct raises the air pressure.

I made the hole big enough to include the NB & CPU area..I'm using a 92mm fan on the right side panel, soon to be a 120mm. On a control. I'll be removing the X plate and using washers made of pcb, to spread the load of the SP-94..Let us know your results..

Case was 35C with the side panel off and 30C after you put it back on?? Ah that isn't happening unless the temp in your room (aka ambient) went down about 5C as well. Actually your room temp would have to decrease by more than that to have the case temp drop that much, considering the heat buildup caused by the components.

Well I have a pic here, more once the hosting is fixed heh

Well it really works, I am looking next week for a thermistor circuit to check my core temperatures with a sensor besides the one soldered to the mb.

pertty cool , i got a 92mm fan in the opening below your fan is at

thats awesome, it looks crazy as all get out also. which makes it even more cool

Yeah heh, it was kind of impressive when I saw the temp drop tomorrow I am getting pc3200 ram so the overclock its on its way. The only thing I and lacking is the will to do the wire trick because I have no more money in the case I short out two wrong pins heh. I want this to reach the lower multis.

if its your only rig keep it safe, i made that mistake, pushed a little too hard, and i dont own a tv or any books really. bedtime 9:00 pm lol

Thats one nice good advice, no wire tricking for now, only when next website gets paid and I have enough money to order many 2500-M heh in case this one blows up.