PWM load temps

M

mdp

Weaksauce
Joined
Sep 17, 2007
Messages
87
System:

Q6600 G0
Abit IP30 Pro
Patriot low latency PC6400 (2x1gig)
Tuniq Tower
FSP Bluestorm II
Evga 8800gts 640mb

I'm still fairly green at overclocking, so bear with me on some of this stuff.

I had the rig running at 3.2Ghz (8x400) for over 12hrs stable running blend tests in Prime95. Vcore was adjusted in BIOS to 1.32v and memory was 4-4-4-12 @2.2v. Idle temps were in the mid 30's with load in the upper 50's/low 60's.

I decided to play around with it some more and was able to hit 3.6Ghz (9x400) but I had to increase the vcore in BIOS to 1.50v (showed 1.42 in CPUZ after vdroop). I had it running Prime for a little over 20mins and was seeing temps in the upper 60's and then got an alarm beeping for PWM being at 80C, so I shut down the test.

Not liking those temps, I decided to see if I could get it better at 3.4Ghz (8x425). I was able to lower vcore down to 1.40 in BIOS (1.36v in CPUZ after vdroop), temps under load were a little better also. Memory is still at 4-4-4-12. I went to bed while Prime95 was running a blend test. Five hours later I was awoken by another PWM temp alarm going off because it was hitting 80C. I shut down Prime, which had showed no errors and been stable for a little over 5hrs.

What's the deal with PWM temps? Is 80C the max? My case has great airflow. I have two Yate Loon 12cm intake fans, a 12cm blowhole fan, a 12cm rear exhaust fan, the PSU has a 12cm fan and so does the Tuniq. I have another fan I was going to add by drilling a hole in the case side and mounting it down low to blow partly on my video card and partly on the northbridge. I can't mount it any higher since it'll interfere with the Tuniq.
 
80C is probally the rated temp of the caps in the CPU voltage requlator circuitry. With the Tuniq you are not getting air movement in the area around the cpu where the VRD is that is normally provided by the "blow by" of the stock downward blowing fan.

You do not want to raise the alarm temp, you want to get some air blowing on the VRD components before you cook a cap.
 
I don't know how in the hell I'm going to get a fan in that area. It'll be a tight squeeze for sure. I'm also already using all the available fan headers on the motherboard. I'm still running at 3.4Ghz right now. Idle temps are 40-38-40-34 in Coretemp. Everything seems to be great other than that PWM issue I had after 5hrs of Prime. My room was pretty warm also since I had two computers running Prime at the same time. Maybe I'll try again tonight with my window open and just this PC running. :)

Almost forgot, here's a screenshot about an hour into Prime95:

3.4overclock.JPG
 
you need to be looking at 40 and 50mm little ones you dont need much, just some air moving right over those parts.

I took a plastic small photo holder, for the acrylic sheet it is made of, heated it in a pan of boiling water (without fan LOL) so I could bend a lip on it. drilled and sanded a proper size hole for the fan blades. attached the fan to it with silicon adhesive/glue, just dots in the corners is all it took, and used a MB mounting screw along the top edge of the board to hold it. Actually looks pretty cool. I water cool so have basically the same problem.

A cheap way of getting the small fans is to buy a cheap HD bay cooler for like $4.99 and rip the 2 or 3 little fans out of it, same fans and hella cheaper then buying them at 4.99 each with shipping added on top of that.
 
Hey Bill, can you post a pic of your mounting solution for that 40mm fan? It's kind of hard to grasp what you're saying without a pic. I'm going to go ahead and order one, then I'll figure out how to get it in there.

As you can see, my case is pretty packed :eek: :

pc%20003.jpg
 
I think I am the only persson in the crountry that does not have a digital camera. I borrowed my brothers to post the pictures on my web site. Would take days to borrow it again and post.

Ok, I knew it would be tight, but wow, I see, you are really hurting for room.

looking at the board layout on newegg (cause that big ass heatsink is in the way) all your VRM stuff is between the CPU and the back IO plate so we do not have to worry about anything between the CPU and the top edge, so one fan will do. This leads us back to where the heck are we going to shoehorn the sucker in.

You do have a bit of a space issue. :p

Well I got nothing else to do while waiting for the 2000th memtest run trying to get 4GB to work on my board, lets see.....

Wow you are going to have to be inventive, while I am looking and thinking it occured to me to mention: sometimes these little fans are "whiney" not loud but because they are small they have a high pitched noise that is annoying, so an inexpensive FanMate 2 made by vantec might be a good idea if you are sensitive to noise, about 5 bucks, or look for a med speed fan, nothing over 4000 rpm, I got a 6000 rpm 50mm on my MCH/Nortbridge and it is like having bees in your head until I turned it down a bit.

Its looking like the only good place would be (refering to your picture) to the lower left. See those two silver housings that are part of the I/O connectors, I think they are for your USB and Ethernet etc. the two silver rectangles just off the lower left of the heatsink? I am thinking a piece of plastic of some sort could be slipped in between those as there is a small gap between. hmm my case cover is off, and I have about the same layout, yep yep that will work their is about a 3/16 gap between the ones on my mb and yours looks the same and there is nothing down in there.

So find a cheap ass picture frame with a plastic "glass" or something easy to cut/form you can mount the fan too. You will have to cut it in an odd shape so it fits between those two items as much as possible and then on the part that sticks out where the fan will go it looks like that bottom edge along the board will need to be trimmed back just a bit to clear a couple of chips on the board and maybe the heatpipe. Acrylic cuts easy with a hacksaw just go slow it likes to crack if you force it, even just a fine tooth hacksaw blade held in your hand with a rag around where you are holding it will do the job in a jiffy. You are going to need a drill or dremel to cut a hole for the fan blades, that is the tricky bit, I had a 1 1/2 hole saw and drill press, you can do it by hand or dremel but its going to take a little time. Do the rough fitting of the plastic "holder" to get it to fit in there and then see where the fan needs to go on the "holder". It is possible to make bends in the acrylic to kinda "point" the fan down a little bit so it is shooting right at that line of inductors and caps with a little hitting that funky curved little heatsink. (Your mosfets are under that.) I would try to aim the fan so 1/2 the air was hitting that little heatsink and the other 1/2 was hitting that row of caps (small cans) and you will be getting air on the little black inductors inbetween. Just drop the acrylic in boiling water for about 2 min and then quickly pull it out with tongs or something (gloves highly recommended !) and gently try to bend it how you want. Go easy and slow or you will break it. Repeat as needed. Cut a slot from the top edge of the "mounting plate" downwards toward the board to help let the part holding the fan point downwards just a tad while the part that is inbetween the two I/O connectors remains straight.



Its going to be a pain, lots of fiddling, trim, test fit, trim, break it, make another, trim. but the life of your board will probally be doubled and stability at extream overclocks improved. Sandpaper cleans up rough edges like a champ.

Those fans are small and light so it will not take much to hold the fan + "mounting plate" in place. It might just even sit in that gap and a folded piece of paper shoved in to wedge the "mounting plate" in place but thats a little cheesy, 2 drops of silicon adhesive would do the trick, I love the stuff, drys fast, holds tight and somewhat flexiable when dry to reduce vibrations, and you can peel it off of most stuff if later you change your mind. I have a tube of stuff called E6000, half my computer is held together with it. Once you get your "mounting plate" all cut and finished, I hold the fan to the mounting plate and with a sharpie or other marker mark a dot onto the plastic where the fan mounting holes are. I then put a drop of adhesive on the marks and let it start to dry a little and then place the fan so some of the adhesive goes up the mounting hole in the fan. Tight as a tick in about 3 minutes. carefull to not get any in/on the blades etc.


So lol, ya, you got space issues, gonna be a pain but you really need some air in there and it will be worth the trouble.
 
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