SUMMARY: Intel goes massive to control Prescot’s heat.
One of our readers in Intel’s Advanced Thermal Design Division took a chance and sent me a pre-production copy of Intel’s latest Prescot Retail heatsink. As many of our readers know, the Prescot runs very hot under “normal” conditions. Intel’s latest answer does not lack for weight – it weighs a mind-boggling 3.8 pounds, most accounted for by the copper base:
The base measures 1½” x 2½” and by itself weighs in at 3.18 pounds. The aluminum fin assembly is flow-soldered to the copper base after a thin nickel coating is plated onto the aluminum fin assembly.
Intel believes that for most users, the massive copper base will absorb enough heat during normal¹ use such that the buffering effect of the base will effectively moderate CPU heat.
The fan is an 80 x 38 mm rated at 213 cfm at 8500 rpm:
It features vanes in the base to straighten air flow. To moderate noise, the fan includes a thermistor mounted to the heatsink’s base; under non-stressed use², the fan turns 2000 rpm and is almost noiseless.
The mounting system is for on-board mounting and includes a backing plate and spring loaded bolts:
In this version, mounting pressure is spec’d at 238 pounds – Intel recommends using a valve-spring compression tool to de-tension the springs for mounting.
Intel includes this in the Retail Upgrade Package:
The Prescot Retail was tested on an Acorp 4S845A motherboard with a modified P4 1500 to read CPU case temps. I varied rpms to give a range so users can match performance to noise tolerance.
| Motherboard | CPU Case Temp | Ambient Temp | Delta | C/W | MBM Temp |
| Acorp 4S845A, 8538 rpm, 103 dBA | 34.4 C | 26.8 C | 7.8 | 0.14 | 31 C |
| Acorp 4S845A, 7503 rpm, 92 dBA | 36.0 C | 27.5 C | 8.5 | 0.15 | 32 C |
| Acorp 4S845A, 6003 rpm, 78 dBA | 36.6 C | 27.8 C | 8.8 | 0.15 | 33 C |
| Acorp 4S845A, 4012 rpm, 62 dBA | 39.1 C | 28.6 C | 10.5 | 0.18 | 36 C |
| Acorp 4S845A, 2001 rpm, 43 dBA | 43.9 C | 29.5 C | 14.4 | 0.25 | 40 C |
Die Simulator results place the Prescot Retail heatsink, at an ear-splitting 8538 rpm, in the topmost rank of P4 heatsinks tested to date (Heatsink Ranking).
Intel’s skunk works has developed an interesting answer to Prescot’s heat profile, although users are warned that there is a potential for long-lasting damage to hearing; in fact, Intel plans to include health warnings on the heatsink’s packaging to comply with relevant OSHA standards.
¹Intel defines “normal use” as “…user activity states as expressed during REM cycles.”
²Intel defines “non-stressed use” as “…conditional states during which Vcore is 0.”
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