Thermalright SI-128 SE Heatsink

Overall Score



I was originally running the stock Intel cooler on the quad core processor in my HTPC.  When I saw that there was basically no hope of running it at anything other than stock clock, I started looking for a better HSF.  Then baligavinod posted this thread, and my search ended.  I decided that I was going to buy the SI-128 SE and see how it handled a quad.  When I got back to school, I purchased this fine piece from Xoxide.

Specifications and Features:
• Dimension : L125 x W145 x H91.5 mm (heatsink only)
• Weight : 510g (Heatsink Only)
• Works optimally with a quiet, low RPM 120mm fan
• Proprietary thru-holes adopted from the HR-series to increase air flow movement
• 8mm heatpipes with high heat transfer efficiency
• Patented support bar design preventing heatsink from deformation over time
• Increased height of heatsink fins for better motherboard compatibility
• Fan blow down design helps to cool CPU surrounding
 INTEL: All Intel P4 LGA775 processors
AMD: Intel Socket AM2 Athlon64 / FX / X2 / Opteron

Package Contents:
• SI-128 SE Heatsink
• Mini Wrench
• Multi-Backplate
• Mounting hardware for sockets AM2 and 775
• Anti-Vibration Strips
• Thermalright Thermal Paste
• Installation Guide

The Package was the typical Thermalright – excellent.  A clean brown box with more than ample protection for its precious contents.





She’s not going anywhere.

This is a good shot of the 4 massive 8mm heatpipes and the “Proprietary thru-holes adopted from the HR-series to increase air flow movement”.

Here is a shot of the ”Patented support bar design preventing the heatsink from deformation over time”.

This is a lot bigger than I expected. :wideeyed: And I was actually starting to worry whether or not it was going to fit in my case. :skeptical:


The bottom looked really nice.  It is very smooth – even though you can see the machining marks.  I didn’t notice any concave or convex points in it either.

The included hardware.

The pieces needed for a socket 775 installation (minus the 4 screws in the upper right.  Those are actually for the AM2 installation set).


The AM2 components.


The all-important, and pretty sweet looking case badge!!!

120mm fan clips, Thermalright Thermal Paste and the Anti-Vibration fan strips.

Installing this beast was a little more difficult than I was expecting coming from the TR U120E where it’s just 4 screws that are fairly simple to put in.  The TR SI-128 SE put up a little more of a fight.



This is the Multi-Backplate with 2 of the posts in.  The posts are secured by rubber O-rings that slip into a grove in the post, holding it in the backplate.


This picture shows how the posts sit between 2 raised points to secure the post from spinning when the screws that hold the heatsink bracket are secured.


Here is the mounting bracket on the top side.  This camera angle shows that there is just enough clearance to get over the voltage regulators.


Now both brackets are on.  The SI-128 SE has the same bracket setup as the Ultima 90.


Like a lot of the other large, aftermarket heatsinks, installation of the SI-128 SE is most easily accomplished with the motherboard out of the case (unless you have really, really small hands).

With the “SilentPipe” heatsink on the Gigabyte P35-DQ6 motherboard, there wasn’t a whole lot of clearance for this baby.  Here, the two heatsinks are actually touching.  I had to do some playing around to see just which way this would fit.  And now, after I completed all of the testing, I have it mounted a quarter turn clockwise and have bent the fins on the top tower of the northbridge heatsink so the two wouldn’t touch.  The way that it was worked fine, I turned it because if I want to stand the case up, I want the heatpipes to be running horizontally so that they are able to function better.  When the case lays flat, the orientation of the heatpipes isn’t important.


A look from the other side.  I would also like to say that the use of the included “Mini Wrench” is a must as there is no way to get a screwdriver in to tighten the screws down.  I have also noticed that the heatsink does slide around a little if you push on it, but a simple solution would be to place a washer on the top side of the mounting bracket to eat up the extra space.  Note: The movement is not bad by any means.  I just wanted to include it here as an FYI.


Showing the clearance a little more.


Now, it’s back in the case and the rest of the components are joining it.


As you can see, it’s a pretty tight fit in my case, a Gateway G6-200 that I salvaged and gave new life.  [URL=""][/URL]


This is how the SI-128 SE is situated in my case now.

The Competition:



Intel Stock Cooler


The stock cooler in my case.

Thermalright Ultra-120 Extreme (U120e)


The TR U120E in my case.


Doesn’t quite fit. :no: :wideeyed:

A side by side comparison between the sizes of the 3 heatsinks.


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