Prolima Megahalems: A Mega Nehalem Cooler

Table of Contents

Prolimatech is a relatively new Taiwanese company with only one product: the Megahalems CPU cooler. Despite Prolima’s relative obscurity, the Megahalems has been making the rounds at several well-known PC enthusiasts sites and getting excellent marks. There’s only one thing left standing between the Megahalems and greatness: a thumbs up from SPCR.

Feb 20, 2009 by Lawrence Lee

Prolimatech Megahalems
LGA775/1366 CPU Cooler
Street Price

Prolimatech is a relatively new Taiwanese company founded in 2008. They have
possibly the most interesting product line we’ve ever seen — it consists of
only one item! Stranger yet, their only product, the Prolimatech Megahalems
CPU cooler, has been making the rounds at several well-known PC enthusiasts
sites and getting excellent marks. It’s impressive for a new brand.

The Megahalems, up close.

The Megahalems is its name, an obvious play on Nehalem (though why the name
is pluralized is a mystery), the codename for Intel’s first family of Core i7
processors. If any CPU deserves a “mega” heatsink, its the 125W Core
i7’s. The Megahalems is another giant aluminum tower heatsink with a six heatpipe
design. It is compatible with Intel LGA775/1366 motherboards only and does not
ship with a fan.

Mounting hardware and accessories.


Prolimatech Megahalems: Key Features
(from the product
web page
Feature & Brief
Our Comment
Minimal air resistance between fins allowing
best balance between noise and performance in range of 800-1200RPM
This is a critical issue. Only testing will tell if they got it right.
Heatpipes are lined up in a straight line
to prevent air back draft allowing air to easily pass through the heatsink
It seems logical to stagger heatpipes
to maximize their exposure to airflow, but at lower fan speeds it may do
more harm than good.
Wide fins with mathematically calculated
thickness to maximize best air-to-surface cooling rate
The more surface area the better.
Uniquely designed, easy-to-install socket
775 and 1366 retention mechanism to increase cooling ability.
The Megahalems is an Intel-only CPU
cooler for LGA775/1366.
Easy to apply, high grade thermal compound,
a perfect sidekick to all Prolimatech heatsinks
To make a proper comparison to other
heatsinks our own reference thermal compound will be used.


Prolimatech Megahalems: Specifications
(from the product
web page
Heatsink Dimension (L)130mm X (W)74mmX (H)158.7mm
Heatsink Weight 790g
Heatpipe Ø 6mm X 6pcs
Suggest Fan 120mm X 120mm X25mm
Suggest Fan Speed 800~1200rpm
Suggest Noise Level (dBA) Below 26dBA
Air Flow 57CFM
Direction of heatsink Faces the rear exhaust system fan


When you think of “mega” sized aluminum CPU cooler,
the Thermalright Ultra-120 eXtreme
comes to mind. In both size and appearance the two coolers are similar, though
the Megahalems has a noticeable gap in the center. The heatpipes are
also aligned in straight rows rather than staggered — this may help in low
airflow situations.

Ultra-120 eXtreme on the left, Megahalems on the right.


Up close. The fins are approximately 0.50 mm thick with 2.00 mm separation.
Fin spacing is about 0.60 mm wider than the Ultra-120 eXtreme and 0.60
mm narrower than the Noctua NH-U12P.


On its side.


The fins are actually composed of four sections — a separating
line can be seen on each side running down the length of the heatpipes. At first blush, this multi-section fin design does not seem promising, as the break in the fin is alother thermal transition point where losses could occur. However, the proof is always in the cooling results.


The heatpipes packed together tightly at the bottom. They are soldered
to the base for better thermal conduction.


The base was flat and had a very dull shine.


The most critical aspect of installation is for the heatsink
to be securely mounted. The more firmly it is installed, the better the contact
between the heatsink’s base and the CPU itself. It’s also less likely to fall
off. Ease of installation is also important — a simple mounting scheme
means less time spent installing, and a reduced likelihood of screwing up.

The mounting assembly demonstrated.


A backplate is placed beneath the CPU socket and bolts with threads
on both sides are secured to it.


Two aluminum side bars are placed over the bolts and nuts are used to
tighten them. There are a second set of holes on these bars for use
with the LGA1366 backplate.


The heatsink is then placed on top of the CPU and a crossbar is fitted
above the mounting plate. Large spring-loaded bolts are then screwed
into the side bars. This is the only step that requires any tools —
the rest is done by hand.


The supplied fan clips are designed to latch onto the outside mounting
holes of a 120mm fan. The Megahalems does not come with a fan, but Prolimatech
provided us with one of their own 120mm fans.


The fan does not sit flush with the entire edge of the heatsink —
there is some separation at the center. This will result in quieter
operation, but will likely cost the Megahalems some performance.


Before thermal testing, we took some basic physical measurements.

Prolimatech Megahalems: Approximate Physical Measurements
790 g (heatsink alone)
820 g (including crossbar, bolts, and fan clips)
Fin thickness
0.50 mm
Fin spacing
2.00 mm
Vertical Clearance
45 mm (measured from the
motherboard PCB to the heatsink’s bottom fin)
Horizontal Overhang
3 mm (measured from the
edge of the heatsink to the top edge of our test motherboard’s PCB)


Comparison: Approximate Fin Thickness & Spacing
Fin Thickness
Fin Spacing
Scythe Ninja 2
0.39 mm
3.68 mm
Thermalright HR-01 Plus
0.45 mm
3.15 mm
Noctua NH-U12P
0.44 mm
2.63 mm
Noctua NH-C12P
0.47 mm
2.54 mm
Prolimatech Megahalems
0.50 mm
2.00 mm
Xigmatek HDT-S1283
0.33 mm
1.96 mm
Thermalright Ultra-120
0.45 mm
1.42 mm

Testing was done according to our
unique heatsink testing methodology
, and the included fan was profiled
using our standard fan testing
. A quick summary of the components, tools, and procedures
follows below.

Key Components in Heatsink Test Platform

  • Intel
    Pentium D 950
    Presler core. TDP of 130W; under our test load, it measures
    78W including efficiency losses in the VRMs.
  • Asus P5Q-EM motherboard. A microATX board with integrated graphics
    and short solid-state capacitors around the CPU socket, and a diminutive northbridge heatsink for maximum compatibility.
  • Intel X25-M
    80GB 2.5″ solid-state drive.
  • 1GB of Corsair XMS2 DDR2 memory. 2 x 512MB PC2-8500.
  • FSP Zen 300W
    fanless power supply.
  • Arctic Silver
    : Special fast-curing thermal interface material, designed
    specifically for test labs.
  • Nexus 120 fan (part of our standard testing methodology; used when
    possible with heatsinks that fit 120x25mm fans)
Nexus 120 fan measurements
16 dBA@1m
1100 RPM
13 dBA@1m
890 RPM
12 dBA@1m
720 RPM
11 dBA@1m
530 RPM

Measurement and Analysis Tools

  • Seasonic
    Power Angel
    for measuring AC power at the wall to ensure that the
    heat output remains consistent.
  • Custom-built, four-channel variable DC power supply, used to regulate
    the fan speed during the test.
  • PC-based spectrum analyzer:
    SpectraPlus with ACO Pacific mic and M-Audio digital
    audio interfaces.
  • Anechoic chamber
    with ambient level of 11 dBA or lower
  • Various other tools for testing fans, as documented in our
    standard fan testing methodology
  • SpeedFan, used to monitor the on-chip thermal sensor. This sensor is not
    calibrated, so results are not universally applicable.
  • CPUBurn
    , used to stress the CPU heavily, generating more heat than most
    real applications. Two instances are used to ensure that both cores are stressed.
  • Throttlewatch
    , used to monitor the throttling feature of the CPU to determine
    when overheating occurs.

Load testing was accomplished using CPUBurn to stress the processor, and the
graph function in SpeedFan was used to make sure that the load temperature was
stable for at least ten minutes. The stock fan was tested at various voltages
to represent a good cross-section of its airflow and noise performance.


Provided Fan Testing

The fan provided by Prolimatech looks like a typical seven-bladed 120mm case
fan. It was a bit mysterious though as there were no identifying marks and no
case fans are listed on the Prolimatech website. It is possible that the “suggested” fan specifications on the main Megahalems product page describe this fan, but this is just a guess.

Brand Prolimatech Power Rating Unknown
Model Number Unknown Airflow Rating Unknown
Bearing Type Unknown RPM Rating Unknown
Hub Size 1.54″ Noise Rating Unknown
Frame Size 120 x 120 x 25 mm Header Type 3-pin
Weight 110 grams Start Voltage 2.4V


SPL @ 1m
20 dBA
1120 RPM
16 dBA
920 RPM
13 dBA
780 RPM
12 dBA
590 RPM

Fan @ 12V: At full speed, the fan was turbulent and had a bit of drone. The measured sound pressure level was 20 dBA, low, at least compared to the average
case fan.

Fan @ 9V: Much of the turblence disappeared, resulting in a 4 dBA decrease. With the airflow turbulence lowered, we noticed a high degree of clicking coming from
the fan’s motor.

Fan @ 7V: The fan sounded very much like the 9V level. The clicking
of the fan’s motor/bearings became more noticeable despite it being quieter

Fan @ 5V: Smooth at a distance, but up close the clicking sounded
more like a rattle.

Overall the fan is fairly quiet, but it is far cry from the much smoother,
high quality fans we prefer. It’s an average low/mid airflow fan with unremarkable

Cooling Results

Prolimatech Megahalems w/ provided 120mm fan
Fan Voltage
°C Rise
20 dBA
16 dBA
13 dBA
12 dBA
Prolimatech Megahalems w/ reference 120mm fan
16 dBA
13 dBA
12 dBA
11 dBA
Load Temp: CPUBurn for ~10 mins.
°C Rise: Temperature rise above ambient (20°C) at load.
°C/W: based on the amount of heat dissipated by the CPU (measured
78W); lower is better.

Overall the Megahalems was a very impressive performer, delivering some of
the best results we’ve ever seen. Both fans kept thermal rise above ambient
below 20°C, even at 5V. The provided fan’s sweet spot seemed to be 7V, while
our reference Nexus fan performed proportionally depending on the fan voltage.
The Nexus fan delivered slightly improved results at equivalent noise levels,
but only by a single degree on average — nothing to write home about.

°C rise Comparison: Prolimatech Megahalems vs.
Nexus 120 fan voltage / SPL @1m
16 dBA
13 dBA
12 dBA
11 dBA
Scythe Ninja 2
Xigmatek HDT-S1283
Thermalright U120E
Noctua NH-U12P
Thermalright HR-01+
Prolimatech Megahalems
All results generated with our reference Nexus 120mm

The Prolimatech Megahalems’s performance was top-notch across the board. It
posted similar results to the Thermalright
HR-01 Plus
and Noctua NH-U12P
with low airflow, and bested the entire field, even the Thermalright
Ultra-120 eXtreme
, when our Nexus fan was set to 12V.


These recordings were made with a high
resolution, lab quality, digital recording system
inside SPCR’s
own 11 dBA ambient anechoic chamber
, then converted to LAME 128kbps
encoded MP3s. We’ve listened long and hard to ensure there is no audible degradation
from the original WAV files to these MP3s. They represent a quick snapshot of
what we heard during the review.

These recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The recording starts with 10 second segments of room ambiance, then the fan
at various levels. For the most realistic results, set the volume so that
the starting ambient level is just barely audible, then don’t change the volume
setting again.


The Prolimatech Megahalems delivered a championship performance, no matter
how much airflow was supplied by the fan. It performed similarly to the Thermalright
HR-01 Plus
in a low airflow environment, but did 3°C better with high
airflow, making it an all-around superior cooler.

We were unsure whether a heatsink with tight fin spacing would do as well with
low airflow, but the Megahalems had just the right design to make it work. There’s little
doubt that the extremely secure mounting system also plays a big role in its
success. We appreciate its simplicity as well — most of the process is
tool-less except for the final step which requires a screwdriver. The mounting
components are also rather large making them harder to misplace. Only the lack of support for AMD processors is a bit disappointing, though this may come in the future.

The Megahalems is a first class heatsink, but availability and
price seem a bit problematic at the moment. The Prolimatech site refers us
to two retailers currently selling the Megahalems, with only the German site
actually having the cooler listed, priced at just under 60 Euros which is about
$77 USD at today’s exhange rate. While that’s fine if you want the latest and
greatest, it really needs to be at most, about $60 (without fan) to truly make it competitive
with a similar performing cooler like the Thermalright HR-01 Plus. That may
not happen until more resellers get their hands on some stock.
Perhaps its part of their marketing strategy to drum up excitement and anticipation.
In any case, the Megahalems joins the Thermalright HR-01 Plus at the very top of our quiet, high performance heatsink list.

Prolimatech Megahalems

* Top-notch performance with both low and high airflow
* Easy, secure mounting system
* LGA1366 compatibility


* Price, availability
* Lack of AMD compatibility

Our thanks to Prolimatech
for the Megahalems heatsink sample.

* * *

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