Presentation of the "DoomsDay" fanless cooling heatsink

[ Index ]

Picture of the element >> .

DATA :

Dimension : L50 x W80 x H80 (mm) ; Where length is measured in parallel with the retainer clip.

Weight : 227 grams (0.227 kg), 8 % lighter than the Q4 element.

Material : Copper

Made for socket 370, Intel Celeron / P3 FC-PGA

Cooling capabilities (verified) :

• Intel Celeron II 700 ( Optimized w.r.t. HW acceleration & power consumption )
  CPU peak temperature : 47.0 C @ 26.5 C MB/cabinet temperature.
  CPU extreme temperature : 49.0 C After 1 hrs 20 min. of testing.
  CPU Typical temperature : 30.0 C @ 25 % average load
  CPU Idle temperature :  27.0 C About 0.5 C above MB/Cab temp.
  CPU settings : 1.4 Vcore, 3.5 Vio, 66 MHz FSB
• Intel Celeron II 700 ( Standard settings )
  CPU peak temperature : 59.0 @ 26.5 C MB/cabinet temperature.
  CPU extreme temperature : 62.5 After 1 hrs 20 min. of testing.
  CPU Typical temperature : 33.0 C @ 25 % average load
  CPU Idle temperature :  28.0 C
  CPU settings : 1.70 Vcore, 3.5 Vio, 66 MHz FSB
• Intel Celeron II 700 ( Optimized w.r.t performance )
  Limited overclocking abilities. System might fail without thermal control/management software or hardware.

Estimated time to create : 2 weeks.

Measurement & Environment factors :

All temperature data are normalized to an ambient room temperature of 20 C.
Air humidity : Normal. Standard livingroom.
All measurements are done in a closed cabinet ( AOpen HQ-45 ), with slightly improved and optimized natural ventilation.
PSU used in all measurements are the "Tranquilizer" PSU(4) or PSU(5), i.e. purely passive cooling and no ventilation fans of any sort; except if otherwise explicitly stated.
The maximal operating temperature for a Celeron 700 FC-PGA CPU is 80 C, with 2.7 C measurment offset. Max Vcore is 2.1 Volts, and Max powerconsumption is 18.3 Watts. The processor is of (6-8-6)stepping with a default Vcore of 1.70 Volts, i.e. not the best version available.

Verified Test results and details :

- Reality testing started on 23. February 2001. [ read ]

- Test of the standard boxed element for Celeron 700 [ read ]

[ Index ]

Testing of the DD element :

After completing the creation of the DD element, it was mounted on top of the CPU with some excitement. Performed different tests to find the characteristics of it. First some standard measurements to see if it holds under normal settings. Then the overclocking possibilities where explored.

All testing done with cabinet cover on.

Testing of standard settings :

CPU clocked at 700 MHz @ 66 MHz FSB.

Results for 1.35 Vcore, 3.4 Vio settings : ( Minimal stable setting )

• Intel Celeron II 700 ( Optimized w.r.t. power consumption )
  CPU peak temperature : 49 C @ 26.5 C MB/cabinet temperature.
  CPU extreme temperature : 54 C (estimate, not measured, not verified)
  CPU Typical temperature : 30 C
  CPU Idle temperature : Same as MB/cabinet temperature (estimate, not verified)
  CPU settings : 1.35 Vcore, 3.4 Vio, 66 MHz FSB

Some performance reducing settings (chipset & cache latency) necessary where necessary for stability.

Temperature data are normalized to an ambient room temperature of 20 C.

Results for 1.4 Vcore, 3.5 Vio settings :

• Intel Celeron II 700 ( Optimized w.r.t. HW acceleration & power consumption )
  CPU peak temperature : 50 C @ 26.5 C MB/cabinet temperature. CPU S.T. (v6.0) mode : Normal Testing.
  CPU extreme temperature : 55 C after 2 hours of CPU Warming. ( Note ! PSU temp 65.8 C.)
  CPU Typical temperature : 31 C
  CPU Idle temperature : 27.5 C ( +1 C of MB/Cab temperature )
  CPU settings : 1.4 Vcore, 3.5 Vio, 66 MHz FSB

Full performance and hardware acceleration settings possible.

Temperature data are normalized to an ambient room temperature of 20 C.

Results for 1.7 Vcore, 3.5 Vio settings : ( Default standard settings )

• Intel Celeron II 700 ( Standard settings )
  CPU peak temperature : 59.0 @ 26.5 C MB/cabinet temperature.
  CPU extreme temperature : 62.5 After 1 hrs 20 min. of testing.
  CPU Typical temperature : 33.0 C @ 25 % average load
  CPU Idle temperature :  28.0 C
  CPU settings : 1.70 Vcore, 3.5 Vio, 66 MHz FSB

Temperature data are normalized to an ambient room temperature of 20 C.

Testing of overclocking possibilities :

Exploring the possibilities for overclocking, showed that they where limited. There is nothing to balance but Vcore levels on the 75 MHz FSB setting. Used together with a large slow moving fan  it might be a "killer" cooling element though. This is outside the scope of the project at the moment. Update sometime I need more speed.

Vio setting for all measures below are standard (3.5 V), closed cabinet. Initial testing using a default Vcore setting of 1.7 volts.

Started out freshly with a 100 MHz FSB setting. This totally failed.

Tried with a 83 MHz FSB setting. This flopped as well. (look futher down for an update on this)

Clutching at the last straw, different settings for a 75 MHz FSB setting where explored.

Testing at 75 MHz FSB : Different Vcore settings

1.7 Vcore : System boots, everything fine. High temperature, but usable.No data recorded.

1.6 Vcore : System boots. Optimized system performance settings are fully possible.
But given the failure because of temperature exceeding specs. this mode is not stable in it self. and would need a guard program to pull the break when the system gets too hot,  or an overheating fan of some-sort for safety.

• CPU peak temperature : n/a, will exceeds 70 C @ 26 C MB/cabinet temperature.
  CPU Typical temperature :  35 C
  CPU Idle temperature : 28 C
  CPU settings : 1.60 Vcore, 3.5 Vio, 75 MHz FSB

1.55 Vcore : System boots, fairly stable, but system Chipset performance settings had to be tuned down to achieve stability. Works under normal circumstances, but system failed on CPU stab test (v.6.0) : Left unattended. Windows crashed. Temperature exceeded 70 C but below 75 C (auto-shutdown).

• CPU peak temperature : exceeds 70 C @ 26 C MB/cabinet temperature. Windows fails.
  CPU Typical temperature :  32 C
  CPU Idle temperature : 27.5 C
  CPU settings : 1.55 Vcore, 3.5 Vio, 75 MHz FSB

1.50 Vcore : Fails after a couple of re-boots. Not stable. Temperature within specs. Don't handle lowered Vcore voltage in this temperature range.

1.45 Vcore : Totally screws up at this setting. Even at most stable settings. Memory problems. etc.etc.

Conclusion :

Element handles the processor (C-700) at it's standard setting. A Lower Vcore voltage is preferred.  An improvement in the processor-element fitting would probably improve the performance of the element. See what can be done.

Adjustments :

Surface treatment : The element looks pretty cool at the moment. Will a surface polish improve cooling capabilities ?

CPU/Element junction : Flatten & polish contact area. More careful mounting of element (no twisting, just downward pressure). Checkout the silver based heat-transfer compound.

Clip pressure : Increase fastening clip pressure. (Feather weight at the moment).

Customize base spacer fitting. ( Dropped this, to much effort & not enough to gain )

#1 : Updated test results : ( after above adjustments )

• Intel Celeron II 700 ( Optimized w.r.t. HW acceleration & power consumption )
  CPU peak temperature : 48.0 C @ 27.5 C MB/cabinet temperature. Ambient temp. 21.3 C
  CPU extreme temperature : 50.0 C @ 21.4 Ambient., 27.5 C MB/Cab temp.  After 1 hrs 20 min. of testing.
  CPU Typical temperature : 31.0 C @ Ambient 21.4 C
  CPU Idle temperature :  28.0 C @ 27.0 MB : Amb temp 21.1 C
  CPU settings : 1.4 Vcore, 3.5 Vio, 66 MHz FSB

Temperature data is not normalized, above.

Normalizing temperature data to 20 C ambient gives :

• Intel Celeron II 700 ( Optimized w.r.t. HW acceleration & power consumption )
  CPU peak temperature : 47.0 C @ 26.5 C MB/cabinet temperature.
  CPU extreme temperature : 49.0 C After 1 hrs 20 min. of testing.
  CPU Typical temperature : 30.0 C @ 25 % average load
  CPU Idle temperature :  27.0 C
  CPU settings : 1.4 Vcore, 3.5 Vio, 66 MHz FSB

> A noticeable drop in peak temperature. More so at higher temperatures. It is likely that Thermal Junction efficiency becomes more critical at higher temperatures. Results still not optimal, got into some trouble with the base spacer fitting. To thick. Mess. The thermal connection couldn't be made in one go. Wiggling. Not optimal, but better than before.

Redoing measurement for the standard settings as well :

• Intel Celeron II 700 ( Standard settings i.e. default Vcore of 1.7 V)
  CPU peak temperature : above 60.5 C ( after 1 hrs 30 min)  temperature. @ 28 C MB/Cab. 21.7 C Amb.temp. PSU melting away at 69.8 ........... 59 Cn
  CPU extreme temperature : ** stab test measure ... use cooler on PSU. guess ... 63 C after hours.
  test starts at 10:49  ... 64 C @ 27.5 C MB and 21.4 C ambient.
  CPU Typical temperature :  34.5 C @ 28 C MB @ 21.5 Amb.    33 Cn
  CPU Idle temperature : 29.5 @ 27.5 MB/Cab @ 21.5 Ambient : PSU (64 C)    28 Cn
  CPU settings : 1.70 Vcore, 3.5 Vio, 66 MHz FSB

Normalizing temperature data to 20 C ambient gives :

• Intel Celeron II 700 ( Standard settings i.e. default Vcore of 1.7 V)
  CPU peak temperature : 59.0 @ 26.5 C MB/cabinet temperature.
  CPU extreme temperature : 62.5 After 1 hrs 20 min. of testing.
  CPU Typical temperature : 33.0 C @ 25 % average load
  CPU Idle temperature :  28.0 C
  CPU settings : 1.70 Vcore, 3.5 Vio, 66 MHz FSB

#2 : Updated test results : ( whenever element fitting is done in one go ... )

Remeasurment of the CPU extreme temperature : Vcore 1.70 FSB 66 MHz Celeron II 700

Testing at 83 MHz FSB : Different Vcore settings

I Later on discovered that by increasing the Vcore by (+0.15 V) to 1.85 volts, it was possible to boot into windows without problems. Any lower settings where unstable. The problem was of course instability at higer temperatures. Have yet not found the temperature limit at which the CPU becomes unstable, but there is a tool available that can stall the processor at this critical temperature limit (Hardware monitor). Will experiment with this later on. Ran at a speed of 875 MHz.