Neat -- an under-slung fan! Who woulda' thunk it?

I've been looking forward to this review. Thanks

Would the cooler also work if the fan blew upward through the fins? This would be ideal for mini-itx in low-profile cases, as the CPU cooler can double up as the case exhaust. Are you able to test this please?

Thanks for the excellent review. This will definitely be on my list of CPU coolers when I build my itx rig

You mentioned in your review that the fan was sleeve-bearing. Considering some mini-itx cases have the motherboard mounted horizontally, would the fan positioning cause a problem (since sleeve-bearing fans aren't the best for horizontal mounting?)



This is exactly of what I was thinking. For this reason and another. Generally, pushing through fins is more efficient than pulling through fins. The purpose of this under-slung fan is to save height. Since top-down blowers generally push air into fins, it would make more sense for the fan to blow push air into the fins.

Thank you for the review, I've been waiting for this one.

This.

Could anyone list examples of smaller mini ITX cases that the Kozuti would fit in but would be too big for other aftermarket coolers?
Thanks!

This = What she/he said = +1

Thanks Mats


May be worth asking them over on THIS THREAD.

Ditto on both points.

Although I don't think it was tested with the fan blowing up, given the very close proximity of all the components (of the heatsink), I doubt there would be much difference in cooling efficacy with the fan blowing either way. I suppose this depends partly on just how tight the space is; in some cases, it might be possible that upflow/exhaust is somehow more restricted than downflow/exhaust... but I doubt it. Bottom line: Easy enough to try once you have it, and if its small/low profile is what you need, there are very few choices anyway.

If the case has vents above the HSF it could make a decent difference.

But this means either the intake will be improved or the exhaust will be improved (depending on which way the fan is mounted). 6 or half a dozen...

There are three potential outcomes: no change, better and worse. My understanding is that with a top mounted fan, a down blowing orientation has been found (through testing) to be the preferred approach in most situations. AFAIK, that analysis has not been conducted for these types of HSF.

Well only way is to buy one, test it and find out

Yes it would be more effective if there was a vent above the cooling fins, or if not then some space for the warm air to move away. And looking at the profile pics, seems there's say 12-13mm space beneath the fan to draw the air up, which should be enough.

I'm pondering a DIY case and using the Kozuti with the cooling fins hard up against the case vent cut to size. The case/cooler will be horizontal, and the convection will help draw heat through the case. Given this, the fan could run at very low speeds, or even switch off at idle. In fact you could ditch the 80mm fan if need be and have an air intake fan on the case, pushing air out of the vent past the Kozuti fins.

The point of a review is so I don't have to buy one, test it and find out.

Nice little thing!

May have to go with one for the next ITX build, which btw, I can't seem to find a more "definitive" choice as far as sandy bridge ITX boards go, they all seem a bit "just ok" right now. Let's get more board reviews! =P

I agree re the 3 possible outcomes, but the point I make is that the differences will be very small. With larger heatsinks where the fins are thicker and there is a larger gap between fan/fins and the base, bigger differences could arise, but I'd be totally surprised if it made any qualitative difference. I mean if it works well for a system w/ the fan one way, I just can't see it not working just about the same way w/ the fan the other way.

You said at the end of the review: "pound-for-pound, and inch-for-inch, the most efficient model yet" and "impressive little heatsink that performs better than we could've imagined." Given that, I was expecting at least a SPCR Recommended tag at the end - what made you hold off? Just the price?

Before such awards are given, there's usually a discussion -- we haven't had a chance to have that discussion yet. But it will get at least a Recommendation.

What's missing from the current generation in your opinion? Have you seen the DH61AG?

Hi,



Generally, air is easier and more efficiently moved by lowering the pressure. The Alpha heatsinks of old did this, and this is how whole-house fans work. A single fan in the attic of a house exhausting air out, can pull air in through any and all open windows anywhere in the house; even the basement. If you turned the fan around and had it blowing into the attic, there is no way that the air would flow out of the windows in the basement.

So, having it blow upward instead of downward would not be any better, I think and might be worse, and it would not cool the motherboard components as well, either.

Which is also why most case fan are used in a negative pressure setup. But cooling a heatsink is quite a bit different, because you don't just want to move as much air as possible - you also want to improve the heat transfer between the heatsink and the fan, which can be done by having a more turbulent air flow. When you have a fan blowing on a heatsink, the air flow through the heatsink will likely be more turbulent, so it can perfectly well be more efficient than having the fan suck air through the fan, even if it moves a little less air.

Now, as for whether this is an important factor here... I frankly have no idea. Not to mention that, in the real world, it will depend on the air flow through the case too. But I definitely recall reading some tests, a looooong time ago, which showed that a fan blowing on a heatsink was a little more efficient than doing it the other way around (in the test conditions considered, of course) - so I'd say it's not completely silly to want to test it.

so this is like 10 degrees hotter than big shuriken

Neil, please explain further what you mean. All fans work by lowering the pressure on one side and increasing it on the other.

Two questions:

1) Is it possible to mount the fan on top of the cooler?

2) Is the cooler compatible with Intel DH67CF?

What he means is that, in practice, when you want to move air through something restrictive, it's more efficient to put a fan at the exhaust rather than at the intake. But AFAICT, that rule of thumbs only makes sense if your only goal is to move as much air as possible (for a given fan speed), for instance for a case fan - if you want to cool down a heatsink, you also have to consider the flow regime, not just the flow rate.

I have a mini itx case M-350.

I would like to mount this cpu fan in my case. Is it ok to let this cpu run on 7v all the time and how is that possible with a PWM (4pin header fan)?

Regards

I just installed a Kozuti this morning. I built a 2500k HTPC in a GD-05 and here were the considerations for a heatsink:

All towers - no chance, 70mm clearance
Big Shuriken - out because I'm using low-latency Ripjaws with a heatspreader
Shuriken - out because it only leaves 5mm above the fan
NT-01 - started with this, but unable to passively cool a 2500k, even with high ambient flow (SST did not rate it for 95w, so not surprised or upset)

So, when I saw the Kozuti, I went for it. The installation was delightfully straighforward, though the heatpipes had to be oriented parallel to the RAM, otherwise the tips or bends would bump the heatspreader. Even in the orientation where it fits, the edge of the Kozuti is touching the heatspreader, enough that I was concerned about making it fit. It keeps the CPU under 70c, quietly, while running 4xPrime95 + Furmark for several hours. Mind you, when I say "quiet", I live next to a busy street in Boulder, so there's definitely ambient noise. I can hear the PC, but I have all three of the 120mm fans in the GD-05 at full power, and the total is a very low, pleasant whoosh that disappears if I watch TV, play a game, or the refrigerator is running.

My main concern is the life of the 80x80x10mm sleeve bearing fan, since replacements that size are almost impossible to find, and in an HTPC the sleeve bearing is in the death-inducing horizontal position. However, the heatsink is bigger than 80mm, and if the fan dies and a replacement is not available, I'll put a 12mm deep 100mm or 120mm fan on top, which will keep the total height to 52mm and allow 18mm of breathing room above the fan. I did email Scythe USA about whether they'll make the Kozuti fan available as a replacement, but that was only a little earlier this afternoon and I haven't heard back.

In the end, if I'd known when I built this machine what I know now, I probably would have used low-profile RAM and a Big Shuriken for easy compatibility with countless 120mm fans. However, I'm very happy with the way the machine is set up now, and am just waiting for Diablo3 to come out before I get a real graphics card. A Ceton will be added shortly.

I installed it last night on my ultra low power i3-2100t in the Antec ISK-100 mini ITX enclosure. That enclosure allows max 40 mm space for CPU cooling in vertical direction. It fitted exactly in the ISK-100.

Findings:easy to install, the Kozuti keeps my i3-2100t 20 degrees cooler than the stock intel cooler, and at much less noise than the stock cooler. As the machine is placed in vertical position I'm curious to find out how well the non-standard fan is doing.. so far it runs extremely smooth.

System idle temperature is now ~40 'C, it was ~60'C before.