Cooljag OAK-H heatsink is identical to the Cooljag OAK-H2 model
in all ways, except for its internally illuminated blue LED fan. Both heatsinks offer a unique approach, largely due to the construction method
which utilizes a ring of skived copper fins wrapped around a central copper column.
CoolJag's OAK-H heatsink adapts the skived
fin technique by turning everything on its side. The end solution is nearly
identical in proportion to the powerful stock Intel
Pentium D heatsink, yet because of the
fan choice selected here thermal results are dramatically different. You'll have to wait until
we dive into the thermal test results to see how much the tangential airflow helps or hinders the
Cooljag OAK-H... On the plus side, the central copper column makes direct
contact with the CPU core, and the skived component which is soldered on to it
radiates the heat out into the surroundings so the thermal pathway is pretty
OAK-H heatsink is equipped with a 93mm 12VDC fan (4-pin pulse width modulation
scales its speed between 1800-3500RPM, generating ~66CFM according the CoolJag's tech specs. The
fan has three blue LEDs which illuminate the frame and impeller brightly. The Cooljag OAK-H heatsink
weighs a hefty 714 grams, necessitating a fixed mounting clip that screws into a metal motherboard rear
support plate (supplied) via four
spring-tensioned screws. Installation and removal of this heatsink requires the motherboard to be taken
out of the chassis. As always, that's never a fun task.
The 93mm diameter fan is controlled by the BIOS on PWM compatible motherboards. Unfortunately like
the OAK-H2 model, when used on legacy motherboards the OAK-H's fan defaults to its lowest possible speed. That speed
is something on the order of 600-1800RPM.... woefully inadequate.
| Model No.: OAK-H|
|Materials: C1000 Copper Skived fins, copper
|Fan Mfg: Everflow F128025DU|
|Fan Spec: 1800-3500RPM, 12V, 0.24A|
|Fan Dim: 25x93x93mm, PWM|
|Heatsink & Fan Dim: 68x96x96mm |
| Weight: 714 grams|
|Includes: mounting hardware,
thermal compound, rear support bracket|
Compatible with Sockets: LGA775
|Est. Pricing: $39USD
Since this is Frostytech,
we're giving you a closer look at what makes the Cooljag OAK-H heatsink
interesting from a technical standpoint. The basic principles on which
it is built appear sound, and with the right kind of fan thermal
performance could certainly improve.
The Cooljag OAK-H heatsink
has an outer ring of skived copper fins as you can
see above, and a central copper cylinder 33mm in diameter which is
partially hollowed out.
This is done to reduce the amount of heat this
center of the heatsink stores, so it acts more like a highway for heat rather
than a parking lot. The processor makes direct contact with that copper block,
and it in turn spreads the energy so the copper fins can work more efficiently
at transferring it to the surrounding environment.
This is the same basic design principle used by
Intel RCBFH-3 reference thermal solution.
The Cooljag OAK-H heatsink will be tested on
FrostyTech's new Intel LGA775 version of the Mk.II synthetic
thermal temperature test platform, and compared against several reference LGA775
heatsinks. The whole test methodology is outlined in detail
here if you care to know what equipment is used, and the parameters under
which the tests are conducted. Now let's move forward and take a closer look at
this heatsink, its acoustic characteristics, and of course it performance in the