Zalman CNPS9500 AT LGA775 HSF


Product: Zalman CNPS9500 AT LGA775 CPU Cooler
Provided By: Zalman USA
Price: $69.95 @ MemoryExpress


A few weeks back I requested the Zalman CPNS9500 AT cooler and Zalman responded by shipping out the very product I requested.  Unfortunately, I was stupid, well maybe not stupid, but I had assumed that this cooler was an updated version of the CNPS9500 LED unit.  I never read to see it's socket compatibility.  This cooler is designed for LGA775 platforms only, and we traditionally run AMD Socket 939 hardware.  I didn't want to look like a fool to Zalman and give them a call and say, "Sorry, I didn't even read your website to see if I could use this cooler."  So the quest was on to build a new test rig that doesn't suck for around $250CDN.  Thankfully, Intel has recently released its Dual Core Pentium 805 processor.  This is a dual core 2.66GHz 2x1MB L2 processor that shows some real overclocking potential and should be able to generate enough heat to test out HSF's pretty well.

To make a long story shorter, I managed to put together a new test rig thanks to Hitachi, Dallmann Computers, Crucial and the patience of my wife.  Thanks honey!

First Look:

The Zalman CNPS9500 AT is almost identical to the Zalman CNPS9500 LED.  They carry the same design that has proven to be an excellent performer.  There are a couple of notable differences however.  The AT cooler doesn't have a blue LED fan - instead it ships with a standard black fan.  If you have a window in your case and you want maximum bling, you may want to stick with the LED.

Zalman 9500AT - Front View
 Zalman 9500AT - Front View


Zalman 9500AT - Front/Side View
Zalman 9500AT - Front/Side View

As you can see above, the design is remarkably familiar.  Zalman has managed to come up with a new fresh design for the 9500 series HSF, and this is just a stripped down version for LGA775.

Zalman 9500AT - Side View
 Zalman 9500AT - Side View


Zalman 9500AT - Bottom View
 Zalman 9500AT - Bottom View


Although you can't see it in the pictures above, the CNPS9500 AT has the Zalman name stamped into each individual fin on the HSF.  Zalman pride I call it, and it works for me.  Also what you can't see in the picture on the right is the finish of the base.  Compared to the base of the CNPS9500 LED, the AT base is very rough and unfinished.  You can see and actually feel with your fingernail machining marks on the bottom of this unit.  I'm sure that if you took some sandpaper and a lapping stone you could gain a few more degrees with this cooler.  The finish is better than some coolers I've seen, but it's pretty rough for a Zalman cooler.

The bundle that Zalman includes is pretty lean this time around as this cooler is designed for only one Socket - LGA775.  As such it only includes mounting hardware for LGA775.  Also included is a small tube of thermal compound and a Zalman case badge.  It's not much but it works.

Zalman 9500AT - Bundle
Zalman 9500AT - Bundle

You may notice that the 9500 AT package doesn't include the FanMate2 controller like the 9500 LED cooler.  The AT package includes an Intel standard 4-pin fan, and forgoes the FanMate2 controller instead.  Your motherboard or temperature software will have to handle fan speed and performance.

On the next page we'll take a look at our test rig, test methods and get into installing this cooler.

Test Rig:

As I mentioned earlier, we had to build a new test rig as good as possible with as little money as possible.  This lead us down the Intel 805 Dual Core road as you can see below in our test system specs.

  • Intel 805 Dual Core CPU
  • Gigabyte 8N-SLI Motherboard
  • 2GB (2x1024MB) Crucial Ballistix PC5300 - DDR2-667
  • HP dvd740 DVD±RW
  • Hitachi 120GB SATA II Hard Drive
  • MSI 6600GT PCIe 128MB GPU
  • Enermax 431W PSU
  • Windows XP Professional with all available updates.
  • nForce 7.15 drivers
  • ForceWare 84.21 drivers

Thanks to the help of our sponsors and gear we had lying around, we managed to put together this rig for around $250CDN.  Not a bad second test rig for the money.


Because we were putting this rig together for the first time, the motherboard was free from the case, and didn't require removal.  If you're board is already installed, it will require removal in order to get the back plate installed.

Zalman 9500AT - Back Plate
 Zalman 9500AT - Back Plate


Zalman 9500AT - Retention Frame
 Zalman 9500AT - Retention Frame

Once you've got the back plate positioned nicely, it's time to turn the board over and install the top mounting frame.  Because of the lever on the socket, it is very important to install the top frame correctly.  Pictured above is the correct way to install the frame.  Notice the "notch" out of the frame on the bottom right.  This will allow the lever to be released and allow you to remove your CPU without removing the mounting frame.

Once you've got the retention frame and back plate screwed together, it's as simple as applying some thermal paste then screwing the HSF down to the frame.  Zalman recommends tightening the screws until they bottom out and are tight.  This is designed to give enough pressure to make things happen.

Below are some pictures of the CNPS9500 AT mounted on our 8N-SLI motherboard.

Zalman 9500AT - Mounted Side
 Zalman 9500AT - Mounted Side

Zalman 9500AT - Mounted - Back
 Zalman 9500AT - Mounted - Back

Zalman 9500AT - Mounted Front
 Zalman 9500AT - Mounted Front

As you can see, there is plenty of room around this HSF.  The design of the cooler puts the wider part above the board and out of the way of the Northbridge HSF and memory modules.  It's important to keep in mind that Zalman wants you to keep the exhaust end of the HSF pointed toward a rear case fan.  This cooler can remove a lot of heat and it needs somewhere to go.

Let's take a look on the last page as we fire up the rig and run some performance numbers.

Testing Methodology:

When testing CPU coolers we install the cooler at least twice to ensure that the cooler is installed properly.  We use Arctic Silver Ceramique on all units to level the playing field.  We also test the coolers with the case sides on to replicate "real world" scenarios.  While it's true that a lot of tweakers leave the side off their case, we are assuming that most people will have their case closed.

To heat things up we ran an instance of the Folding @ Home client on each CPU core and set it to "slightly higher than idle" CPU usage.  We also run Prime95 to really make things toasty.  When running these programs CPU load is pinned at 100% and it's gets warm in a hurry.  Load temps with the fan at low and high are recorded 45 minutes after the tests are initialized.  For idle temps, we boot up and let the machine sit for 15 minutes to get things warmed up.  CPU load at idle is generally between 1%-2%.

Take a look below as we turn up the heat on this heatsink as we take our Intel 805 CPU up past 965 speeds and see if the Zalman CNPS9500 AT can cool off 7.8GHz of Pentium D goodness.

Performance Tests:

In this our first LGA775 HSF review we have only the stock Intel HSF to compare with.  Obviously the Zalman CNPS9500 AT will outperform it, but by how much?  Will better cooling enable the processor to overclock higher?  Let's have a look.

Stock speed of this processor is 133x20 = 2.66GHz.  It runs with a quad-pumped FSB which is effectively 533FSB.  Other Dual Core Intel processors run at 800FSB (200 quad-pumped), so this processor has a disadvantage in the bandwidth department, but due to it's low FSB, has an advantage in the overclocking department.  Stock voltage is 1.375v and we never ran it above 1.525v when overclocking.  To stress the coolers to the max, we overclocked the CPU as high as we could and remain stable.  Stability was determined by running Prime95 and Folding @ Home.  If the system could remains stable overnight, we considered it stable.  Our maximum stable speed with the stock cooler was 3.66GHz (180x20) at 1.525v, and with the Zalman CNPS9500 AT we achieved 3.9GHz (195x20) at the same 1.525v.  I'm sure I could break 4GHz with this processor, but because I had to purchase it with my own money, I don't really want to hose it.

We ran tests with the fans set to "Auto" and "High".  Auto fan speed scales with the heat output of the CPU and varies greatly in rpm.  It is impossible to recreate the same RPM on each cooler at different degrees, but we included the numbers anyway.  If you are not an enthusiast and you wonder how these coolers compare without tweaking or adjusting fan speed, the "Auto" numbers will be your friend.  If you don't care if a HSF makes a little noise, take a look at the numbers when running the fan at 100% - "High" speed.

Stock Temps
Stock Temps

At high speed both the stock cooler and the Zalman CNPS9500 AT make a fair bit of noise.  The Zalman cooler bests the stock cooler by a chilly 10 C though.  That's a pretty big margin for sure.  When running auto fan speed the margin is narrowed to 8 C.  Keep in mind because the Zalman HSF is keeping the processor cooler, the fan is also running slower.  At idle both coolers do a fine job, but the AT keeps things about 6 C cooler.  Not bad for a dual core Pentium D.  Let's take a look below at the overclocked results.


This time around we take the CPU and push it until it's on the bleeding edge of stable - then we back it off until it is stable.  With the stock cooler we managed to push this 2.66GHz CPU up a whole GHz to 3.66GHz.  At this speed things got a little warm for sure.  With the Zalman cooler installed we were able to squeeze another 240MHz out of this processor without bumping up the voltage.  That puts us in the 3.9GHz range and brings us to an incredible 46% overclock.  I believe that if we tried a little harder we could have made 4GHz and a 50% overclock, but I didn't want to fry this CPU just yet.

Max Overclocked Temps
Max Overclocked Temps

As you look at the chart above and see the margins narrow up even more than at stock speeds, you must keep in mind that the Intel 805 processor is clocked higher under the Zalman cooler.  After a certain point every little MHz bump increases the heat output exponentially, and with the stock cooler I couldn't get to 3.7GHz stable, let alone 3.9GHz.  Even when cooling 7.8GHz of processor, the Zalman CNPS9500 AT keeps things just under 60 C in out 20 C ambient test area.  It's a rise of 39 C above ambient, but that's not bad consider what it is trying to cool.


After a bit of a blunder and requesting a HSF that I didn't have a test rig for, I actually had a good time playing around with an Intel rig again.  The last Intel rig I owned was a Celeron 300A and it too was a great overclocker.  The Zalman CNPS9500AT seems to be a perfect fit for Intel's 805 processor and allows you to keep things cool enough to squeeze out a bunch of extra performance.  If you're looking for a good cooler to keep your toasty LGA775 gear cool, you must check out the 9500 AT for yourself.  You won't be disappointed.


  • Medium Weight Cooler.
  • Great Performance.
  • Quiet at stock speeds when not overclocking.
  • Nifty design with 3 "Figure 8" heatpipes.


  • Finish of base a little rough.
  • No Fan Controller.
  • LGA775 only.

This is a nice cut-down package from the CNPS9500 LED cooler.  It is built only for Intel 775, but it should be able to found cheaper than the previous Zalman cooler with all of the bells and whistles.  It has a unique design that has proven to be very, very good. Rating
Software Pack:
Total Score 9.0


I'd like to thank Zalman USA for letting us take a look at this unit.  It's been an interesting ride as we get back into some Intel gear.

If you have any questions or comments regarding this review, please head on over and post them in our forum at the "Comments" link below.  Thanks a bunch!!