- Joined
- Apr 3, 2002
- Location
- Bloomington, IN
Hello!
I just wrote up a little article for the main overclockers.com site on how to mount the Zalman passive northbridge heatsink (ZM-NB47J) on the Intel 865/875 boards without resorting to permanent means like epoxy. The technique: making your own custom spring clip. Here's a copy of the article, while I wait for it to appear on the main site.
"Mounting a Zalman Passive NB Heatsink on an Intel P4 Board without Epoxy"
Introduction and Motivation
I recently started looking for a quieter northbridge heatsink to replace the stock heatsink. After much searcher and reading of web reviews, I found that the Zalman ZM-NB47J is a passive heatsink that is more than capable of properly cooling a modern northbridge heatsink, so long as the chipset does not have built-in graphics. In fact, some reviews (and see here and here and other links that I seem to have lost.
... ) have shown that this passive heatsink allows just as good an overclock as some active cooling solutions.
Thus, the Zalman heatsink seemed like the perfect choice. However, there was a snag: the pushpin-type heatsink mount was only designed for motherboards with holes surrounding the northbridge. (Read: Athlon boards.) Intel P4 boards, by contrast, have a bizarre hook and spring clip mount. Uh-oh.
The solution that most people have come up with is simple and elegant: use Arctic Silver thermal epoxy to permanently attach the heatsink. However, I have major qualms about permanently attaching anything to my motherboard (an Abit AI7). I believe that modifications to a system should be as transparent as possible, and part of that transparency includes being reversible. So, I decided to create my own spring clips for the Zalman ZM-NB47J.
Supplies and Tools
This is probably the cheapest mod you'll ever do. I bought 200 feet of 16-guage galvanized utility wire for under $5. (If you can find it in shorter lengths, it's even cheaper.) For tools, all I need was a ruler, a pair of pliers, a pair of wire cutters, and a pair of needle-nose pliers.
Technique: Creating the Spring Clip
To start off, you'll need a template. Look at the template below in Figure 1.
Figure 1: Basic template for the spring clip.
In the template, the longer side is 2+7/8 inches, and the shorter side is 1+7/8 inches. There is a vertical line halfway along the longer side. Along that line, draw two dashes 7/32 of an inch from each side. Lastly, draw two dashes 1/16 of an inch from the ends of both the longer sides.
Now, cut a 12 inch length of wire, straighten it, and line it up along line L. Using the pliers, grip the wire at point d so that the edge of the pliers are just below that point. Bend the wire 90 degree to the right towards point e.
Next, use the same method to make a 90 degree bend in the wire at point c towards point b. See the Figure 2 below.
Figure 2: Spring clip after the first two bends.
Next, use the same method to make a 90 degree bend at point e into the paper. I have personally found that it is best to actually grip the wire about 1/16 of an inch inside from point e so that the wire exits the bend at the position of d. Make a similar 90 degree bend into the paper at point b. See Figure 3.
Figure 3: Spring clip ready to make hooks.
Okay, we're now ready to make the hooks in our new spring clip. Using needle-nose pliers, grip the portion of the wire near point d that faces into the paper. Bow the wire out slightly towards point f. Then, move the needle-nose pliers along the curve and continue to bend the wire. Continue in this fashion until you have bent the wire in a gentle loop with diameter similar to a pencil. See Figure 4.
Figure 4: First hook on the spring clip.
Do the same at point b, making a hook that faces towards point a.
Now, bend the two hooks at approximately a 45 degree angle outwards towards the corners. Trim the hooks off, and you're done. See Figure 5.
Figure 5: The completed clip.
Note that you may need to experiment with the angle of these final bends and how far down you trim the hooks, to be conservative. You can always trim more off later.
Technique: Mounting the Heatsink:
Notice that one one side of the heatsink, there are two adjacent rows of fins that are shorter; this side of the heatsink should face your CPU. On the opposite side, there is one row of shorter fins; that side should face the AGP slot. You should wedge your clip along the center of the sink (There should be 5 fins on each side of the clip.) See Figure 6 to get a better idea of where the clip goes. See Figure 7 to see the mounted heatsink.
Figure 6: Close-up view of the ZM-NB47J heatsink.
Figure 7: The ZM-NB47J heatsink with our custom mounting.
I found that there was no nead for any additional shims on the heatsink, as the core of the chipset is level enough for the heatsink to sit level on the core with a thin layer of Arctic Silver III.
Another thing that you can do is make an identical clip with the hooks in the opposite directions. In this way, you can obtain a complete mount that engages all four loops on the motherboard. I myself did this, as can be seen in Figure 8.
Figure 8: The mounted heatsink with 2 clips.
However, I didn't find any real advantage to using two clips. The heatsink was quite secure with just one clip, and it was fairly difficult to mount the second clip on top of the first. I'd personally recommend just sticking with one.
Results and Concluding Remarks
The system, using the custom-mounted heatsink, maintained stability and the same overclock as with my stock Abit cooler. For reference, I'm using a Pentium 4 3.0C overclocked at 3.45 GHz at 1.575 volts. I'm runing 3 x 512 MB Kingmax PC3500 at a 5:4 ratio with 2-8-3-3 timings at 2.65 volts. Using this heatsink, I've been able to run 10 loops of Sisoft Sandra's CPU arithmetic, CPU multimedia, Memory, and Cache & Memory benchmarks. There have been no problems in gaming or folding, and I've been able to run several loops of memtest86 with no errors.
One thing that I would have liked is to have found a stiffer steel wire. This would have made a "springier" spring clip, but I was unable to find such at Lowe's hardware. On the flip side, this was most likely much easier to form.
On the whole, I'm very satisfied with the results. I have completely passive cooling of the northbridge, my overclock has been unaffected, and I can always choose another cooler later if I so choose, so I'm not locked into the current cooler.
I just wrote up a little article for the main overclockers.com site on how to mount the Zalman passive northbridge heatsink (ZM-NB47J) on the Intel 865/875 boards without resorting to permanent means like epoxy. The technique: making your own custom spring clip. Here's a copy of the article, while I wait for it to appear on the main site.
"Mounting a Zalman Passive NB Heatsink on an Intel P4 Board without Epoxy"
Introduction and Motivation
I recently started looking for a quieter northbridge heatsink to replace the stock heatsink. After much searcher and reading of web reviews, I found that the Zalman ZM-NB47J is a passive heatsink that is more than capable of properly cooling a modern northbridge heatsink, so long as the chipset does not have built-in graphics. In fact, some reviews (and see here and here and other links that I seem to have lost.
... ) have shown that this passive heatsink allows just as good an overclock as some active cooling solutions. Thus, the Zalman heatsink seemed like the perfect choice. However, there was a snag: the pushpin-type heatsink mount was only designed for motherboards with holes surrounding the northbridge. (Read: Athlon boards.) Intel P4 boards, by contrast, have a bizarre hook and spring clip mount. Uh-oh.
The solution that most people have come up with is simple and elegant: use Arctic Silver thermal epoxy to permanently attach the heatsink. However, I have major qualms about permanently attaching anything to my motherboard (an Abit AI7). I believe that modifications to a system should be as transparent as possible, and part of that transparency includes being reversible. So, I decided to create my own spring clips for the Zalman ZM-NB47J.
Supplies and Tools
This is probably the cheapest mod you'll ever do. I bought 200 feet of 16-guage galvanized utility wire for under $5. (If you can find it in shorter lengths, it's even cheaper.) For tools, all I need was a ruler, a pair of pliers, a pair of wire cutters, and a pair of needle-nose pliers.
Technique: Creating the Spring Clip
To start off, you'll need a template. Look at the template below in Figure 1.
Figure 1: Basic template for the spring clip.
In the template, the longer side is 2+7/8 inches, and the shorter side is 1+7/8 inches. There is a vertical line halfway along the longer side. Along that line, draw two dashes 7/32 of an inch from each side. Lastly, draw two dashes 1/16 of an inch from the ends of both the longer sides.
Now, cut a 12 inch length of wire, straighten it, and line it up along line L. Using the pliers, grip the wire at point d so that the edge of the pliers are just below that point. Bend the wire 90 degree to the right towards point e.
Next, use the same method to make a 90 degree bend in the wire at point c towards point b. See the Figure 2 below.
Figure 2: Spring clip after the first two bends.
Next, use the same method to make a 90 degree bend at point e into the paper. I have personally found that it is best to actually grip the wire about 1/16 of an inch inside from point e so that the wire exits the bend at the position of d. Make a similar 90 degree bend into the paper at point b. See Figure 3.
Figure 3: Spring clip ready to make hooks.
Okay, we're now ready to make the hooks in our new spring clip. Using needle-nose pliers, grip the portion of the wire near point d that faces into the paper. Bow the wire out slightly towards point f. Then, move the needle-nose pliers along the curve and continue to bend the wire. Continue in this fashion until you have bent the wire in a gentle loop with diameter similar to a pencil. See Figure 4.
Figure 4: First hook on the spring clip.
Now, bend the two hooks at approximately a 45 degree angle outwards towards the corners. Trim the hooks off, and you're done. See Figure 5.
Figure 5: The completed clip.
Technique: Mounting the Heatsink:
Notice that one one side of the heatsink, there are two adjacent rows of fins that are shorter; this side of the heatsink should face your CPU. On the opposite side, there is one row of shorter fins; that side should face the AGP slot. You should wedge your clip along the center of the sink (There should be 5 fins on each side of the clip.) See Figure 6 to get a better idea of where the clip goes. See Figure 7 to see the mounted heatsink.
Figure 6: Close-up view of the ZM-NB47J heatsink.
Figure 7: The ZM-NB47J heatsink with our custom mounting.
Another thing that you can do is make an identical clip with the hooks in the opposite directions. In this way, you can obtain a complete mount that engages all four loops on the motherboard. I myself did this, as can be seen in Figure 8.
Figure 8: The mounted heatsink with 2 clips.
Results and Concluding Remarks
The system, using the custom-mounted heatsink, maintained stability and the same overclock as with my stock Abit cooler. For reference, I'm using a Pentium 4 3.0C overclocked at 3.45 GHz at 1.575 volts. I'm runing 3 x 512 MB Kingmax PC3500 at a 5:4 ratio with 2-8-3-3 timings at 2.65 volts. Using this heatsink, I've been able to run 10 loops of Sisoft Sandra's CPU arithmetic, CPU multimedia, Memory, and Cache & Memory benchmarks. There have been no problems in gaming or folding, and I've been able to run several loops of memtest86 with no errors.
One thing that I would have liked is to have found a stiffer steel wire. This would have made a "springier" spring clip, but I was unable to find such at Lowe's hardware. On the flip side, this was most likely much easier to form.
On the whole, I'm very satisfied with the results. I have completely passive cooling of the northbridge, my overclock has been unaffected, and I can always choose another cooler later if I so choose, so I'm not locked into the current cooler.
