Japanese Dragon

by Guest Tue Jun 10, 2008 10:30 am

Giant Passive Scythe Orochi Cooler

“Orochi” in Japanese mythology means a snake-like creature with several heads (eight, to be more exact). There is a similar dragon in Russian folklore fairy-tales, too. However, The Russian monster belches smoke and fire and has nothing to do with cooling.

Anyway, I am sure not the mythic dragons belch fire, and maybe there is something we don’t know about Japanese dragons. So, let’s leave myths and fairly-tales aside and check out this interesting product.

The Scythe Orochi package is exactly what is should be for a cooler of this size. It is large enough for a compact liquid-cooling system and is covered in all sorts of useful info:

There you can find cooler key features, the list of bundled accessories, technical specifications and a list of supported platforms:

In other words, everything that could have been written and posted on the package is there. The only thing missing to complete the cooler description is the benchmark results, however, it is good they are not there, because we wouldn’t believe these numbers anyway Smile

The accessories bundled with Scythe Orochi are quite typical for the coolers from this Japanese manufacturer:

Among the included items there are:

Retention bracket for Socket 754/939/940 and Socket AM2 mainboards;
Retention bracket for Socket 478 and LGA 775 mainboards;
Two clips for Socket 478 and LGA 775 retention;
Backplate for Socket 478 and LGA 775 mainboards;
A set of screws and washer-pads;
Two wire clips for attaching the fan to the heatsink;
A 1g pack of SilMORE thermal compound;
Installation manual in four languages.

You can easily notice that the accessories bundle includes everything you might need for proper cooler installation and use. I wish they had included more wire clips for the fans, four instead of two, because it could have saved overclockers a few seconds of precious time trying to figure out how to attach a second fan.

Scythe Orochi cooler is not just big, it is really BIG! It measures 120 x 194 x 155mm and weighs 1285g with one fan. At the same time, its design can hardly be considered unique:

Ten copper heatpipes come out of the copper nickel-plated base and pierce a large aluminum heatsink. There are 35 aluminum plates in the heatsink array plus three smaller plates in the upper part of the heatsink. Large plates measure 120 x 100 mm and are about 0.5mm thick. They are spaced out at 4mm from one another. Three smaller plates are 120 x 48 mm and are placed at the top, where the heatpipes enter the heatsink:

So, the size of Scythe Orochi’s heat dissipating surface it will make about 8702cm², which is a today’s record among contemporary cooling systems. For example, if we take the manufacturers’ claimed specifications for granted, then the heat dissipting surface of Zalman CNPS9700 LED cooler heatsink makes 5490cm², and ZEROtherm NV120 Premium can boast 6748cm².

There is another relatively small aluminum heatsink (82 x 44 x 48 mm) installed at the bottom of the cooler, right above the heatpipes. Its ribs do not touch the main heatsink, so all aluminum plates are actually hanging on the heatpipes. All 10 heatpipes are spread out in four alternating rows featuring two or three heatpipes per row:

This construction solution seems quite logical and results from the engineers’ intention to distribute the heat as evenly over the heatsink as possible.

The heatpipes in the base of the cooler are flattened and placed in two rows one above the other. The heatpipes in the bottom row that bear the major thermal load go into the upper part of the heatsink array, while the heatpipes from the upper row pierce the lower part of the aluminum heatsink.

I don’t think they could have thought of another way of fitting 10 heatpipes into such a small area. I would like to add that the heatpipes seem to be soldered to the base, not glued.

by Guest Tue Jun 10, 2008 10:31 am

You can find the detailed installation instructions for Scythe Orochi in the enclosed manual in four languages (PDF file, 4.23MB). In fact, there is nothing new we could tell you about it, because the only thing you have to do is mount the appropriate retention frame to the cooler base:

Socket 754/939/940/AM2

Socket 438 & LGA 775

After that you apply thermal interface to the processor heat-spreader. For K8 platform you lock the cooler retention to the standard plastic socket frame, and for Intel platform you attach the retention clips to the PCB with bundled screws and then lock the Orochi retention frame on to these clips:

So, the retention shouldn’t cause you any problems with cooler positioning on an Intel processor, because you can actually turn it in any direction. The new cooler can also be installed four different ways on a Socket 754/939/940/AM2 platform thanks to a square base and the opportunity to attach the retention frame in any way. Looks like everything is just perfect, however, I would like to draw your attention to one fact (quoted from the manual):
<BLOCKQUOTE>Important Notice:
Due to the large dimension of this CPU Cooler, this product may not fit into all PC cases. Please check the dimension of your PC case and surrounding components to make sure this CPU cooler can fit into your system.</BLOCKQUOTE>
As you may have already guessed, from the first cooler photos, it is important not only to position the cooler facing the correct direction, but primarily to fit it into the system case. The photo below illustrates this major difficulty: Scythe Orochi is installed onto ASUS P5K Deluxe mainboard inside ASUS ASCOT 6AR2-B system case:

Looks like the cooler heatsink did fit into the case, but unfortunately, without the fan. If we put a fan on top of the heatsink, the side panel of the system case will not close (we moved the side panel case fan outside):

However, I did find a way out. I attached the 140mm fan to the heatsink side facing the mainboard chipset. So, Scythe Orochi was cooled with two fans: a standard 140-mm fan on the heatsink side and a 120-mm fan on the case side panel facing the top pf the heatsink. Here I would like to point out that in this case the CPU temperature was 7ºC lower than in passive mode but in an open testbed. I’d like to add that the distance from the cooler base to the lower edge of aluminum heatsink plates measures 55mm, so Scythe Orochi will not be in the way of any electronic components around the processor socket including memory modules with tall heat-spreaders.
As for the most optimal positioning of this cooler, the manufacturer recommends the following in the manual:

In other words, this gigantic cooler has to be installed with the ends of its heatpipes facing down to ensure maximum cooling efficiency. However, most standard ATX cases do not allow this, because when the heatpipes of Scythe Orochi are facing up, its top part goes ~70mm past the top of the mainboard. In this case even if your system case has a PSU at the bottom, Orochi heatpipes will hit against the top case panel or fans installed on it. So, looks like the happy Scythe Orochi owners will be able to install it only one way in most cases: with heatpipes positioned horizontally.