Zalman CNPS 8700 LED Heatsink Review

Zalman has been making some of the most innovative and quiet after-market heatsinks in the computer industry for several years.  They have had to keep up with the thermal trends as processors became more powerful over the years, which has had the unfortunate side effect of making their products rather large.  One of Zalman’s best performing heatsinks is their CNPS 9700 NT, but it is also a behemoth of a paperweight and cannot be used in smaller cases like their original products.

Zalman has gone back to the drawing board and delivered a new sibling into their CNPS (Computer Noise Prevention System) line of products.  This new little sister is low profile like their original products, so it will fit in more cases without worrying about clearance space and utilizes the heatpipe technology implemented in their newer line.

The newest member of the CNPS line comes in a standard blister pack with all of its assorted mounting goodies.  Included in the package is the cooler itself, an installation manual, semi-universal mounting braces, a Fanmate, and all the screws, gromits and clips needed for installation.

The CNPS8700 LED is made from 100% pure copper, just like all of the recent CNPS heatsinks, but at 475 grams is significantly lighter than the previous generation (the CNPS 7700 weighs in at a whopping 918 grams).  The new heatsink looks very similar to the 7700 at first glance, but has actually been redesgined to incorporate two heatpipes.  These heatpipes extend from the mirrored contact base and connect all of the cooler’s copper fins together. One side effect of having the fins soldered to the heatpipes is that the space between the fins is permanently set (it was very easy to bend the fins on the 7700 into a wad).

The heatsink’s profile is alot different, too.  It incorporates a 110mm fan at its center, but is only 67mm tall, so it can fit in more low-profile cases (although it won’t fit into a Shuttle or other tightly-packed enclosure).  The double ball bearing fan is made from clear plastic, so as to catch the blue light emmitted from the tiny blue LEDs in the fan’s hub.  The fan is secured to the sink above the base with two screws.

The contact plate of the heatsink is extremely smooth and polished to a mirror finish, just like the rest of Zalman’s recent cooling products.  There is no need to lap this contact plate, and will certainly make maximum contact with your processor without a lot of thermal paste.

Airflow is directed downwards over the fins, as the CNPS7x00 line does.  The advantage of this design is the added cooling benefit enjoyed by surrounding motherboard components.  Zalman’s 9×00 line directs airflow in one direction, usually towards the case’s exhaust fan, which neglects the mosfets and other warm components usually surrounding the CPU.

Although the mounting hardware is similar to that of the 9700 and 9500 line, installation is a little different.  If you already have another Zalman heatsink installed, you probably won’t be able to use the existing mounting brackets, as I discovered.  Our test system already had a 9700NT installed, and we figured we ould use the existing plastic mounting bracket (so we didn’t have to unmount the motherboard to install a new heatsink).  Unfortunately the plastic mounting bracket is different enough that you must use the one included within the 8700’s packaging.  We would have preferred to use the aluminum bracket of the Zalman ZM-CS1.

Installation on a socket 775 motherboard isn’t as straightforward as previous heatsinks, but is direct enough.  You begin by securing the included  plastic mounting bracket to your motherboard (the bracket should be positioned to accomodate the CPU’s tension lever).  You must attach a backplate to the underside of the motherboard, and then attach the top bracket to this mount by threading the included screws through the motherboard’s mounting holes.

The retention bracket has two screw holes that can accomodate other Zalman heatsinks, but the 8700 must be mounted with a metal clip.  A special retention clip must be used to snake around the heatpipes near the base.  The clip must be turned 90 degrees before it can be slipped between the heatpipes, then can be flipped to the orientation that will secure the cooler to the mounting bracket.

The obvious “clip” end of the bracket is slipped over one notch in the retention bracket, but there is no clip on the other end.  You must slip a special “key-clip” thingy over the narrow end of the clip, and then push down with your thumb.  Pushing down will catch the clip-key onto the other notch, securing the heatsink to the retention bracket.  This mounting method wasn’t obvious at first, but is actually much easier to install once you know the trick of it.

Installation on an AMD motherboard is alot easier, as no mounting frame is needed.  The standard metal clip is the native clip usable on AMD motherboards, so installation is alot more straightforward.  Just position the 8700 LED heatsink, thread the clip through the heatpipes, and then hook the clips onto the motherboard’s retention bracket.

The Zalman CNPS 8700 heatsink was tested with our current standard test machine, the [OC]ModBox, which includes the following hardware

• Intel E6600 Core 2 Duo Processor
• Asus P5W DH Deluxe Motherboard
• 4GB A-Data DDR2-800 @ 1000 Hz
• eVGA 8800GT 320MB PCI-e video card
• Soundblaster X-Fi Platinum
• Sony 16X DVD-R burner
• 500GB Western Digital SATA HDD
• Windows Vista Ultimate (64-bit)
• CoolIT Ram Fan

Core temperatures were measured using Intel’s Thermal Analysis Tool (TAT), which measures the internal core temperature of each individual core on the CPU’s die.  Our Asus motherboard can throttle the fan’s speed depending on CPU load and temperature, but we connected the fan directly to a fanmate to measure the temperatures at high and low fan speeds.

It may seem a bit unfair to compare this heatsink with a much larger heatsink, but we wanted to show the dynamics between these two products.  The Zalman 8700 performs much better than a Intel’s OEM heatsink, but of course doesn’t do as well as Zalman’s current flagship.  The 8700 holds its own when you remember that it has only half the mass of the 9700, so it is one of the better-performing heastsinks for its size.

It’s no real surprise that the Zalman CNPS 8700 LED heatsink doesn’t perform as well as heatsinks that are much larger, but is has excellent performance for its size.  If space is at a premium (as in a low-profile case) then the 8700 is more than adequate to do the job.  The new heatpipe technology gives them an advantage over the 7700 line without sacrificing the profile.  This heatsink is a perfect match for a Home Theater PC case, which typically have similar clearance issues with taller heatsinks.  You may have some side-clearance issues depending on your motherboard, but in most cases the 110mm fan won’t be a problem.

The mounting system is about as complex as Zalman’s other heatsinks, which can be simple or involved depending on your motherboard type.  No method is extremely difficult, but it may require removing your motherboard.  The heatsink is highly compatible with most motherboards made within the past few years, and has enough thermal performance to handle modern processors.

The fan is a little noisy at top speed, but most users will either use the included Fanmate to hush it, or let the motherboard dynamically adjust the fan’s speed.  The load of a typical home theater PC isn’t that intense, so you can safely slow the fan down in this application.

Since the 8700 is all copper, it is priced about the same as other all-copper heatsinks, which will offer better performance.  The main reason to use this heatsink is because of its forgiving profile.  It performs great for its size, so if you have a need or a smaller heatsink then the Zalman 8700 LED is just what you need.