Review: 3aCooler's Zebra AlCu1 heatsink

Cooling

Oct 1, 2003 by Russ Kinder

Product: Zebra AlCu1 CPU Cooler
Manufacturer / Supplier: 3aCooler
MSRP: ????????

Specifications
Weight: 390g (Heat sink only)
Dimension: L84 x W68 x H41,5(mm), without fan
Materials: Aluminum with Copper center section.

The Design

The 3aCooler Zebra AlCu1 is a heatsink for Socket-A (AMD) consisting of 25 aluminum and 13 central copper fins with a solid triangular core. One might guess that the name Zebra comes from its striped Al / Cu look. The material for the fins is fairly thick, with greater than average spacing between them. Both characteristics bode well for low airflow cooling. The fins are sandwiched together by three protruding bolts, in a way that immediately brings to mind the construction method of the Zalman flower coolers. As with the Zalmans, the individual pieces are squeezed together and then the bottom is machined flat and polished.

In a departure from most heatsink designs, the base of the AlCu1 is rectangular, and narrower than the socket, much like the Thermalright SLK800. The narrow sides are just wide enough to rest on the rubber pads on an XP. The cooling fins curve upwards in a quarter circle to the flat top of the heat sink. The unit is topped by a plastic mounting that is drilled for a 60mm fan.

The curved fins do a couple of things: they ensure that the heatsink will clear any motherboard obstructions, and they allow air from the fan to cool the voltage regulators next to the socket. The HS is quite modest in size, compared to many of the models SPCR has tested in the past.

In order to keep within the SPCR heatsink testing methodology, a 60 to 80mm fan adaptor was used to mount an 80mm L1A fan. Some sample tests were run with a couple of the 60mm fans that I have on hand, but it was instantly obvious that from a noise perspective, none of them would acceptable. The 80mm fan simply has a much better airflow-to-noise ratio.

The attachment mechanism is a 6-lug clip that is captive within the triangular core, again, much like the Thermalright SLK series. It is a tool-less design with a thumb catch on the cam side. I found the thumb catch to be only marginally successful. It made putting the heatsink on easier, but getting the leverage required to free it for removal for more work than it would be with a conventional clip. Putting the clip on the cam side of the socket also makes it more likely that it will be crammed in a small space between the motherboard and the PSU in some cases, making removal even more difficult.

The Finish

While not mirror smooth, it's smooth to the touch and polished enough to read text in its reflection. Some machining marks are visible but are very minor.

Testing

The testing was done in accordance with the SPCR heatsink testing methodology. Each test was repeated three times and the results shown are averages. Overall the variance between any of the test results was less then 5%. For idle temperatures the machine was booted from cold and allowed to come to a stable temperature. The load results were obtained by running CPUBurn continuously until the temperature stabilized, generally at least 30 minutes.

The test bed

  • Abit NF7 motherboard, with latest BIOS revisions. Modified with passively cooled NB.
  • XP2100 Thoroughbred B, at stock speed and voltage (1.65v, 62.1 Watts max)
  • 1Gig of PC2100 RAM.
  • ATI 9500 graphics card, passively cooled with Zalman Hp-80A heatpipe cooler.
  • Seagate barracuda IV Harddrive.
  • Enermax 365 PSU, modded with an L1A @7 volts.
  • 80mm Panaflo L1A reference fan.
  • Temperatures are read from the internal thermal diode of the CPU with Motherboard Monitor 5.


The setup looks something like this, but with the ABIT board.

With the motherboard setting alone on top of the upper level and the PSU and HDD mounted on a layer of foam on the lower.The same tests were also run with an SLK-800 heatsink as a control. This was done to provide a reference for the performance of the AlCu1 as well as to allow easier comparisons with the other HSF reviews here at SPCR.

Test results: In a break from heatsink manufacturer convention, 3aCooler recommends that the AlCu1 be used with the fan blowing upwards, away from the heatsink. Since most finned heatsinks perform less efficiently this way this instruction is a bit unusual. For that reason the AlCu1 was tested with the fan blowing in both directions. The results are tabulated below.

The Thermalright SLK800 data is included as a check against a known reference. It was measured on the same test bed under the same conditions. The room ambient temperature was a constant 22 degrees C.

HeatSink
Temp C - Idle
Temp C - Load
Delta T
°C/W
Fan voltage
12V
7V
5V
12V
7V
 5V
12 V
7V
5V
12V
7V
5V
Z-Bra Blowing
36
38
42.5
48
59
74
26
37
52
0.41
0.6
0.84
Z-Bra Sucking
38
46.5
54
51
66
>79
29
44
>57
0.49
0.71
>.92
SLK-800
32
41
47.5
40.5
57.5
70
18.5
35.5
48
0.3
0.57
0.77

The AlCu1 in this configuration performs better with the Panaflo 80L in the conventional down blowing direction. Since the heatsink is being tested in a modified form (with a 60-to-80mm adaptor and 80mm fan) its possible that the results would be different with a 60mm fan mounted directly to the heatsink, perhaps a bit better. But for the same airflow, we know it would be louder.

In comparison to the SLK-800, it's clear that the ALCu1 is no new king of the hill. But it's important to remember that it is nearly 25% lighter, and probably half the cost (the cost is a total shot-in-the-dark. I'm guessing a $20 price tag, which seems to be inline with what a couple of the other online reviews were suggesting.)

Particularly at the 7 volt range it runs fairly close to the Thermalright, only 1.5° behind. With the Panaflo at 5 volts it has clearly passed its useful cooling point with a processor of this wattage. But even at this limit its only 4°C behind the SLK.

Conclusion

Overall the AlCu1 is a pretty nice effort for being the very first product from a brand-new company. If priced right it could be an excellent value contender. I would like to see an upgraded version, scaled to fit an 80mm fan stock. Only time will tell if one of those is in the works.

Much thanks to 3aCooler for the Zebra AlCu1 samples. As far as we know, the unit does not appear to be available yet in North America. We'll let you know when it is.

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