Dynatron DC1U-B02

February 28, 2003 admin Uncategorized 0

Copper heatsink for 1U cooling – Joe

SUMMARY: An interesting design for 1U cooling.

P4 1U

Size: 88.5 x 62 x 29.5 mm high; Weight 345 grams.

The good guys at Dynatron were nice enough to send a sample of their 1U heatsink, model # DC1U-B02 to test out. In contrast to most heatsinks, this one features a blower rather than an axial fan. The heatsink is a copper skive design, which means that the fins are literally peeled out of the copper base – there are no solder joints with this technique.

The blower is a YS Tech Model #BD125015BB-2F – an 50 x 15mm squirrel cage fan rated at 6.1 cfm @ 7800 rpm, 50 dBA¹ (my noise estimate). I found it to be noisy – I measured its noise at 70 dBA with a Radio Shack sound meter 8″ above the fan, about the same as a Delta 38 (about 69 dBA). It’s safe to use a motherboard fan header (3.6 watts).

The base is a copper baseplate:

Base

I found that when running a fingernail over it, you could feel and hear the polishing marks on its copper base.

The mounting bracket is a good one:

Bracketp

Mounting requires removal of the motherboard; the back plate is held in place with four screws. Once in place, the system is very secure and clipping the heatsink in place is very easy.

THE TEST

I tested the Dynatron DC1U-B02 on an Acorp 4S845A motherboard with a modified P4 1500 to read CPU case temps.

TEST RESULTS – Motherboard
Motherboard

CPU Case Temp

Ambient Temp

Delta

C/W

MBM Temp

Acorp 4S845A

41.4 C

21.2 C

20.2

0.35

35 C¹

Delta = CPU temp – Ambient Temp
C/W = Delta / CPU Watts

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.

Motherboard results place the Dynatron DC1U-B02 in the low rank of heatsinks (Heatsink Ranking) tested to date.

CONCLUSIONS

Cooling in the restricted space of a 1U rack is a challenge, and one that will be increasingly difficult as CPUs increase in power. Heatsinks for 1U cooling are among the most difficult to design, considering the limited footprint available.

Considering its diminutive size, the Dynatron DC1U-B02 does OK, but it is noisy – maybe OK in server racks.

Thanks again to Dynatron for sending this our way – an interesting approach to 1U cooling.

¹Note that manufacturers measure fan noise usually 3 feet from the fan.

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