Thermalright HR-01

Heatsink Test – Joe

SUMMARY: An excellent heatsink when used with a 120 mm fan placed directly on its fins; fanless peformance will vary widely based on case conditions.


110 x 60 x 160 mm high; Weight 525 grams.

The good guys at Thermalright were nice enough to send their latest Thermalright heatpipe, the HR-01 for a test spin.

This heatsink is a fanless design, using four heatpipes in a “U” shaped configuration through a very large aluminum fin array. The HR-01 is designed for AMD’s Athlon64 FX 3200+ (socket 939/940) / Athlon64 3200+ (socket 754) and above, Intel’s Pentium-4 socket 478 up to 3.2 GHz and Pentium-4 LGA775 3.2 GHz and above.

This is the first fanless heatsink from Thermalright, and the heatsink’s height and number of fins (31) attest to this design.


In addition, each fin features an interesting hole pattern


which is designed to improve airflow. Note that the spacing between the fins is generous, so that air can easily circulate through the fin array. The base


is nickel plated copper and fairly smooth – no polishing ridges apparent.

Parts are available for K8 or P4 mounting:



The Thermalright HR-01 was tested on an Acorp 4S845A motherboard with a modified P4 1500 to read CPU case temps. I have a problem testing fanless heatsinks, as performance will clearly depend upon airflow through the case. Since this is so case dependent, users mounting fanless heatsinks will experience varying performance levels; the single most telling variable for any user will be airflow through the heatsink and air temp at the heatsink.

Considering these issues, I decided to test the HR-01 with a Delta 120 x 25 mm fan (Delta WFB1212M, 72 cfm) placed directly on its fins in addition to still air testing – no airflow through the heatsink. Testing in this manner shows what the HR-01 is capable of delivering with enhanced airflow.


Case Temp
Ambient Temp
Die Temp¹
HR-01, 72 cfm
26.9 C
19.4 C
HR-01, Still Air
68.5 C
19.8 C

¹Die Temp as measured by the P4 on-die diode, per MBM.

Interpreting C/W: For every watt (CPUw) that the CPU
consumes, the HSF will limit the CPU’s temperature rise to (C/W x CPUw)
plus the temperature at the HSF’s fan inlet. For example, at an ambient temp of 25 C, a C/W of 0.25 with a CPU radiating 50 watts means that CPU temp will increase 50 x 0.25 = 12.5 C over ambient temp, or 37.5 C. The lower the C/W, the better.

Results place the HR-01 in the topmost rank of P4 heatsinks tested to date (Heatsink Ranking) using a fan directly on the heatsink’s fins. Performance as a fanless heatsink will depend greatly on individual usage patterns and airflow through the case.


Thermalright’s HR-01 is an excellent heatsink when used with a 120 mm fan placed directly on its fins. Users mounting this heatsink in a fanless mode will experience performance dependent upon airflow though the case and air temps at the heatsink. Frankly, considering its excellent performance with a fan, I would opt for a quiet 120 mm fan rather than fanless operation.

Thanks again to Thermalright for sending this our way. The HR-01 is available now from The Heatsink Factory.

Disclosure: Joe Citarella has a financial interest in a company developing thermosyphon products for electronic chip cooling.

Email Joe