[dkf295]

Howdy all, got a bit of a predicament.

Currently, I'm trying to get as much as I can out of my current rig. Basic stats:

Mobo: ASUS M4A79XTD EVO
CPU: Phenom II X4 965BE

Motherboard has a built-in mosfet heatsink. However, the heatsink still gets super hot when I'm overclocking and under load, possibly causing instability and at the very least generating extra heat for my CPU (I've got a corsair H50). As a result of my H50, I've got one fan on either side of the radiator in an exhaust configuration.

So, I'm looking to get some simple active cooling for the existing heatsink. My issues are twofold.

1. Due to bulk of radiator and accompanying fans, the MOSFETs and heatsink are right underneath one of the fans, I do have a little over an inch of clearance but there's really nowhere to mount a fan
2. I don't want to just blow hot air around up into the radiator if I can avoid it. I have an exhaust fan at the top so some would get sucked up there but I'd still like to draw as much heat away from the CPU as possible.

Short of moving the radiator and fans outside of the case to get more clearance and room to work with (not a good option for me), can anyone think of any decent and preferably cheap active cooling solution for my MOSFETs? I was initially thinking something crazy like a heat pipe on the mosfets transferring heat down to a heatsink, then having a fan blow that out the back of one of the PCI slots in my case but I haven't been able to find anything like that online. I have found aftermarket MOSFET heatsinks with attached fans but they're super expensive (like $25/pop) for what I'm trying to do.

I hope I did a good job of describing my setup, I can take pictures if necessary but not tonight as I don't have my camera.

 

[dragosmp]

You described pretty well, as far as I understand there isn't a lot of room around the MOSFET & I/O panel area because of the H50 radiator and fans. The MOSFETs are crowded below the fan and between the H50 rad and CPU socket. Moreover you would want to avoid pumping MOSFET's heat towards the radiator or the socket.

When you install a watercooling rig there is a big chance of overlooking MOSFET cooling. The thing is the heat produced by the MOSFETs is located where the mosfets are, so if you wanna evacuate it, you just have to lead it somewhere. If you move the H50 outside the case you have the room to add a decent fan on the VRM radiators - problem solved. If you keep the H50 in the case you need a heatpipe cooling system because you need to guide the heat from that crowded place to somewhere you can dispose of it, like in front of the upper exhaust fan. The third way isn't very effective, but it could be a stopgap: just put a fan that blows air somewhere in the direction of the VRM - it would recirculate that heat in the case and maybe even heat the CPU/H50 a bit, but it could cool the VRMs enough so that overall it would OC better.

My 02: new cheap motherboards skimp on VRM quality and/or VRM cooling and they're the weakest part of a mobo, if a mobo brakes most of the time it's the VRMs. That's why cooling them is important and a 25$ investment that you could recycle on other future boards could be a good idea.

 

[KhaoticKomputing]

I hve a question. How are your fans set up? I use this board and to help keep them little bugger cool I made sure to have grat flow across them. On my cooler master 212+ I played around with moving the pull fan(the back side fan) down some. not a whole lot of room with that dorky ASUS heatsink but by loweing the fan (dont quote me here) maby less than a quarter inch droped the temp of the heatsink under stress. Then when i ditched the ANTEC 902 for my current case its a little bit cooler.

I use the same board you have and i HATE the heatsinks on the board. They are just plain stupid looking. The way a computer case flows those ******ed things miss ALOT of air in the fins..then there are these big goofy fins with the ASUS stamp on them that block all the other little fins from getting any kind of air flow at all. I'm about to take a hacksaw to that fin to see if it helps disipate heat, if that dosnt work im moving to somthing better...would I wouldnt mind testing the stock heatsink seen here with some kind of smaller fan rigged to it somehow. I feel your pain on the this board, only complain with it..and its not SLI ready

Is your radiator inside your case? I dont know if your case has the little plugs/holes to place the radiator outside of the case but It might be worth driling a 2 holes to put in outside if its inside.

 

[dkf295]

Quote:

Originally Posted by KhaoticKomputing;13047618
I hve a question. How are your fans set up? I use this board and to help keep them little bugger cool I made sure to have grat flow across them. On my cooler master 212+ I played around with moving the pull fan(the back side fan) down some. not a whole lot of room with that dorky ASUS heatsink but by loweing the fan (dont quote me here) maby less than a quarter inch droped the temp of the heatsink under stress. Then when i ditched the ANTEC 902 for my current case its a little bit cooler.

I use the same board you have and i HATE the heatsinks on the board. They are just plain stupid looking. The way a computer case flows those ******ed things miss ALOT of air in the fins..then there are these big goofy fins with the ASUS stamp on them that block all the other little fins from getting any kind of air flow at all. I'm about to take a hacksaw to that fin to see if it helps disipate heat, if that dosnt work im moving to somthing better...would I wouldnt mind testing the stock heatsink seen here with some kind of smaller fan rigged to it somehow. I feel your pain on the this board, only complain with it..and its not SLI ready

I've got a kind of meh case but just spent $100 on this mobo while trying to prepare for a wedding so my appetite for spending money is kind of dwindling. PSU is on bottom for reference. Front intake fan on the bottom, the airflow isn't awesome and have been looking for a possible replacement fan. I've also got an ok 140mm fan on the top as exhaust roughly square with the CPU. As mentioned previously, I have two fans on the radiator in exhaust configuration.

I do have negative pressure, I took my old (stock) CPU fan and mounted it to the grill on my case so it's blowing on the top of my GPU and in the general vicinity of the VRM and it seems to help a little bit but it's godawful noisy. This makes my pressure positive with all fans on full. However, it doesn't seem to make a huge difference...

So bottom line is, I need at least one new fan but don't want to buy one until I know exactly what I'm going to do with it.

As far as heat pipes, that's starting to sound like the best idea for me if I can vent the air out one of the PCI slots. I'd still be radiating some heat onto the radiator and would be a bit close to my graphics card but my card has always been super-cool and I'm hoping to vent directly out of the case which should help limit collateral damage.

However, I can't find exactly what I'm looking for online. Closest I could find was this but I'd need to modify it. Can one actually bend a heatpipe significantly without breaking it? If I could get the top heatsink more horizontal I'd have the clearance and I'd have to measure to be sure, but I think that would place me at exactly where I'd need to be to vent air out the back.

 

[KhaoticKomputing]

Let's see if I follow you, you have the fans for the cooler as exhaust, 1 140mm top exhaust fan, and your old CPU cooler fan as an intake fan?

if thats right, I would look to swaping out the 140mm fan to somthing else. 140mm fans are mostly quiet, but lacking in flow. you can get betterflowing 120's with very little noise diff. What fan is the 140mm and what cooler did the other fan come from?
I would still like to know if your Water radiator is outside the case, or inside the case?

 

[dkf295]

Quote:

Originally Posted by KhaoticKomputing;13048149
Let's see if I follow you, you have the fans for the cooler as exhaust, 1 140mm top exhaust fan, and your old CPU cooler fan as an intake fan?

if thats right, I would look to swaping out the 140mm fan to somthing else. 140mm fans are mostly quiet, but lacking in flow. you can get betterflowing 120's with very little noise diff. What fan is the 140mm and what cooler did the other fan come from?
I would still like to know if your Water radiator is outside the case, or inside the case?

The 140mm fan is kind of junky but does an ok job, it's the stock fan from the case. I guess I wasn't that concerned about it since it's so close to the fans for the radiator. Sure, it draws some heat away from the radiator but there's a LOT of exhaust on the top rear of the case (two 120mms on the radiator and a 140MM) as it is. As for the fan mounted to the grill, it's the stock fan for my Phenom II x4 965, probably the same as your stock fan. While it's quite powerful it's quite noisy and thus I really don't bother using it, and until i have a final plan for MOSFET cooling there's not much point in getting a quieter fan to replace it.

The radiator is inside the case, there's two fans on either side of it venting air out the back of the case. From a cooling perspective I know it'd be best to have the radiator on the outside of the case but since this is a closed loop system I can't run the hoses through the holes in the back of the case without cutting the tubes and somehow re-sealing them. I'm sure it's possible but I'd rather not risk it, having to spend $50-$60 on a new system and possibly having a water damaged mobo if it leaks. So at the very best I could have the second exhaust fan on the outside of the case and mount the radiator to the inside of the case.

Again, my main issue is cooling the MOSFETs, even if I were to move the second exhaust fan to the outside of the case (hurting my static pressure) it'd only net me an extra 55mm, any MOSFET cooling solution I've seen so far would either not fit or would be sitting right in front of the intake for the radiator, sucking mega-hot air in. I could reverse the fans and draw in cool air from the outside but then I'm just blowing hot air on the MOSFET heatsink.

I can always use more CPU cooling but even when overclocked +700mhz and my GFX card oclocked as well I seem to be having the most issues with the MOSFETs. Granted, ambient heat isn't helping but I rarely overclock my graphics card and since I'm venting hot CPU air directly out of the back of my case the CPU isn't going to be transferring that much heat to the MOSFET, just a little bit from the radiator which is about 3 inches diagonally from the MOSFET heatsink.

 

[dkf295]

Alright, after MUCH hassling with bluetooth on my phone I was at least able to take some basic pictures that may help.

And yes, I've got an extension cable for that power plug in the mail so it won't be sitting in front of the fan for the radiator.

 

[KhaoticKomputing]

Ok, first off I would recomend putting your fan that is squished between the Water cooler and the end of the case on the out side of the case with a fan gaurd on it(might want to think about cutting the "built in fan grill out aswell??). that might move the other fan closer to the end of the case allowing more air to flow over the Heatsink in question, I hope this make's sence...A forum member on here(and friend) Loune use's an H50 mounted on the outside of his case, with 2 highpowerd fans and a rheobus fan controller, SWEAR'S BY IT! he's tryed to talk me into getting that same set up.

No clue how you would go about getting the radiator outside the case, thought the lines would pop off or unhook some how didnt know peeps had to "mod" or mess with to achive this.
Might want to look at some fans moving mroe CFM than the stock fans. there are some great air moving fans that done make tons of noise, cheap too!

 

[dkf295]

Yeah, think I'll need to move at least one fan out of the case. I just ordered a 120MM fan to mount to my grill to blow on the MOSFETs, a 140MM fan to replace my bleh top exhaust fan, and a 92mm fan to sit in my spare 5.25" bays as intake. Hopefully this will mean more airflow in general and cool things down.

 

[gildadan]

My thoughts are why not mount the rad to the top of the case where the 140 is now. Then put the fan at the back of the case as an intake and redirect some airflow down to the vrm hs. This could be done cheaply with some plastic I am sure. It might look a little ghetto but you wanted cheap and you could do that without spending anything I would think. Other option would be to do like I said and instead of building a duct get another little fan to do the job for you.

 

[dkf295]

Quote:

Originally Posted by gildadan My thoughts are why not mount the rad to the top of the case where the 140 is now. Then put the fan at the back of the case as an intake and redirect some airflow down to the vrm hs. This could be done cheaply with some plastic I am sure. It might look a little ghetto but you wanted cheap and you could do that without spending anything I would think. Other option would be to do like I said and instead of building a duct get another little fan to do the job for you.

That's one thing I didn't consider, the downside is that even if I do a perfect job with the plastic "airduct" and it's completely airtight that my static pressure is going to go down, which is important when you're dealing with radiators. I could always mount a more powerful 120mm as an intake if needbe.

I guess I'll see how things go with my new fans (should get here wednesday, so sad I need to wait ;_; ) and summer, probably won't need to crank on the AC for a while... 88 today but 57 high tomorrow, next highest temp in the next 5 days is 62. Crazy huh?

 

[dkf295]

Well, I got my fans and despite a couple headaches my MOSFETs/sink seem to be a fair amount cooler.

What I got: 1x 92mm fan. 1x 120mm fan, 1x 140mm fan

What went wrong:

1. Two of the screws I used to mount fans to the radiator stripped the threads in the radiator itself and I absolutely COULD NOT get them out without significantly damaging the radiator. Cut off as much of each screw as I could, still a nice seal with 3 screws on each side.

2. The 120MM fan I was going to have blowing on my MOSFETs was terrible.

What I did:

1. Moved one of the two fans I had mounted to my radiator to the outside of the case. No decrease in performance = happy me!

2. Was pleasantly surprised to find that the 140mm fan I bought to replace my case's stock 140mm fan (top exhaust) was a significant improvement over the stock fan. Woot!

3. Since the 120mm fan I got did absolutely nothing, I decided to mount the 92mm fan to the ventholes on the side of my case, blowing on the MOSFETs. I was just barely able to fit the 120mm fan in my two spare 5.25" bays. It really doesn't do much I guess every little bit helps.

MOSFETs are quite a bit cooler, I'm pretty sure I can live with my case the way it is now. Thanks for the advice all!