Silent mod for stock S775 P4 cooler

by Bjoern Roy , March 25rd 2005

The Northwood S478 P4's were great. Rather cool running and easy to transform into a silent PC without much trouble.

When the first Prescotts arrived i was really bummed. How could Intel replace a great CPU with such a hot running sucker? After a few revisions, they got better and better, but i still tried to get my hands on Northwood's were ever the need arrised to build a cool and silent running PC.

It took quite a while for an iteration of the Prescott to come along, that i considered worthy to be used in such an environment. The new P4 3.0Ghz 'J' is the first CPU after the great Northwood 2.8Ghz, which is suitable for silent needs in my book.

But on top of the fact that the Prescott's have always been hot-rods, Intel has shipped stock fans with them from day 1, which defy any human logic. Non-cage, so that you have to be careful to not cut off any loose cables or worse... your fingers. Incredibly loud with an aweful pitch, albeit not being very efficient. And the worst connect-to-your-board technology that you could come up with, no matter how drunk you are.

So when i tried my first 3.0 'J' in a silent PC project, i looked for alternatives. I always despised the modding industry. Cooling fans and modding kits for 30$ - 150$, being more centered on looking 'cool', than delivering on that account. Pompous constructions for a lot of money, without being very efficient. I have seen a few exceptions to this rule, but they weren't cheap by any means.

Looking for a proper S775 cooler was even worse. The stupid concept that S775 connectivity is, makes the offered fans look 'fancy' at best, but testing a few of them reassured my mind... I always despised the modding industry.

So, just like i did for my precious S478 and S370 sockets in the past, i came up with a simple, easy, cheap solution to get a P4 3.0Ghz 'J' running reasonably cool and extremely silent, by using the stock fan and a few tricks.

Since i figured that i am not the only one who has the hatred for the S775 cooler, i decided to share this solution.

So here we go!

Our beloved friend. The mighty stock S775 Prescott cooler. Ugh! Don't throw it away yet, as we will 'patch' this to our needs, rather than start from scratch.


Your last few seconds! Anything you want say to your beloved ones? Oh wait, no one loves you...

Untie all the calbes and get a nipper ready.


Cut away the fan at the 4 vertical posts.


This is what is left. This is a solid basis for a proper CPU cooler. Now, what else do we need....


For starters, aself-adhesive felt pad. This one is white, the one i actually used is black. Your local home depot should have something like this, or some sort of anti-glide rubber.


Cut out a few 1"x1" pieces. You will only need 4, i made a few more here.


This is a 80x80 mm Arctic Cooling Pro TC fan. Very quite. Usually my favorite fans are from Papst, but this one is very cheap and i found it to be even better than all comparable Papst fans i tried, since it vibrates much less. While the Papst are dead silent when you hold them in your hand, they can get rather loud by transfering mechanical vibrations to your PC. For todays silent PC designs, mechanical vibrations is a bigger problem than the fan noise itself!

The Pro TC runs at about 1000-2000 RPM. Under normal circumstances i tracked it at 1200-1700 RPM in my silent PC. This results in sufficient air draft while being almost unnoticable.

Stick the felt-pads to all 4 sides of the fan as shown in the picture above.


Now carefully bend out the 4 posts of the stock cooler and slide in the fan. The posts will be bend out slightly and thus produce enough force to keep the fan in place, while the felt (or rubber) will reduce the vibration propagation to a minumum.


For the propagaion part, its essential that you don't slide the fan down all the way, but leave 2-3mm space between it and the cooler body, as you can see above.

Thats it! The felt pads cost a few cents each and the Pro TC fan can be had at around 2 USD.


I like the Tagan 380w power supplies quite a bit. There are some others that are amazing, too. My favorite being one from EKL which has a 120x120 mm Papst fan in it. These kinds of power supplies are very silent, but they also don't move out much air, so the exhausted hot air of our new fan might be stuck in the case and accumulate to unreasonable amounts, resulting too much necessary RPM of the fan, and thus noise.

So i usually take another 80x80mm or as shown here, a 120x120mm fan (this is an awesome Papst 4412 F2GLL) to slowly move out hot air. As you can see, there is a fan controller on the far left (the littel black box). Its a Zalman fanmate. I didn't use one of these for the CPU fan here, the Pro TC is directly connected to the Gigabyte board. I disabled the 'smart fan' mode in the mainboard bios, since the Pro TC controls its speed sufficiently on its own.

I use the Zalman fanmate to control the big Papst fan. The fanmate can be controlled from about 5-12v, i would guess. In my environment, its sufficient to have the Papst run at about 6v. After running a few minutes, the CPU temperatur stabalizes and the Pro TC runs at about 1600 RPM. Together with the Papst at 6v, and the Tagan power supply, this is so extremely silent, that the idle noise of the Seagate Barracuda HDD is the dominating part! And the Barracudas are already among the most silent available.

The Papst F2GLL can be had for about $12-15 USD here in Germany. You might be able to find a simple silent 120x120mm fan in the sub 5$ price range of the ProTC as well, haven't investigated that yet. Most cases don't have the ability to hold a back 120x120mm fan anyway, more likely a 80x80mm, so you can simply take a second ProTC there. The only hefty item on you list will be the power supply, and its my experience that you shouldn't save on that account. A proper power supply costs money. And one that is efficient enough and well thought out to be cool, costs even more. The Tagan is in the $50-60 USD range, the EKL with the 120x120mm fan is in the $60-70USD range. I consider both to be worse it.

Since the HDD will be the loudest item in your PC with the above configuration, it makes sense to decouple it with one of those silicon blocks or strip tensioned brackets.

So there you have it. Hope this is of any help to some of you.

Best regards
Bjoern Roy




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