TennMax Stealth Review

This little heatsink is marketed as a video chip cooler for Voodoo 3 boards. It consists of 11 layers of aluminum plates, 1 9/16″ square, cooled by a small ball-bearing fan which sits in a hole in the middle of these plates. This design enables the Stealth to maintain a low 10 mm profile which is what is needed for cooling chips on video cards; too high and you lose a slot (BTW: does anyone know why a lot of peripheral cards are made “upside down”? You would think that all the components would be on the other side to aid in heat dissipation.)

I tested the Stealth using my peltier cooler test rig but only running it at 5 volts – at 12 volts, 40 watts of heat is too much for the Stealth. The first thing I did is scrape off the thermal pad – IMHO grease is better. At 5 volts the peltier is putting out about 15-20 watts of heat so it is a good test of cooling capacity. As a reference point, I tested the Stealth against an ARX heatsink which is a little larger and used for individual chip cooling. It is about the same height but almost 2″ square and uses a cast aluminum base with a fan sunk in the middle, similar in concept to the Stealth.

Interestingly both the Stealth and ARX maintained the peltier at 45.5 degrees F with ambient temperature of 73 F – not bad considering the heat load. I use the ARX to actively cool AGP chips on BX boards – the “greeny” that you see on BX boards is a joke (Please don’t call ARX asking for these – they are wholesalers only). At a minimum, if you don’t pull the thing off and use thermal grease, you are running the AGP chip on the hot side. Why a board manufacturer can’t slap on a little grease is beyond me.

Anyhow I have to modify the ARX because it is too big to fit exactly in the mounting holes to replace the useless greeny – I drill some holes, use thin nylon ties to hold it in place etc. Now the great thing about the Stealth is that it’s a direct fit to replace the greeny – either you drill out the mounting holes on the Stealth a little bit to use the mounting pins from the greeny or just use the plastic push-pins that come with the Stealth (easier). Voila – you have an actively cooled AGP chip. It is low enough that it does not interfere with most CPU heatsinks (it is about 3/32″ below the top of the Slot 1 connector and about 1/8″ wider than the greeny) so I think this is a neat application for the Stealth (it also looks really cool!)

The one concern I do have is a pragmatic one – if you look at the Stealth’s fins, you will notice they are very close together. They are close enough so that you can barely fit an index card between the fins. Hmm – I wonder what happens when dust builds up and starts to clog these fins.

My first thought was to go to the dryer’s lint filter and start to sprinkle it on the heatsink and see what happens. I then thought about my wife’s reaction to scattering lint all over the house and quickly abandoned that approach. So what I did was to take a little piece of scotch tape and begin to cover up a section at a time of the fan’s exit slots. There are 8 of these, so the results which follow show the rise in temperature as the slots become more “clogged’:

No clogs: 45.5 degrees F
1 clogged: 46.2
2 clogged: 47.7
3 clogged: 49.8
4 clogged: 52.9
5 clogged: 57.4
6 clogged: 61.3
7 clogged: 66.0
8 clogged: 76.6

Results are about what I’d expect – little degradation initially, then escalating as more get clogged. This clearly suggests some diligence on fan cleaning.

I then tested it unclogged and with the fan off, and this is peltier meltdown – the Stealth would be improved greatly with a tach output and a 3 pin connector/adapter for direct attachment to a motherboard fan pin – fan failure would not be pretty for a hot video chip.

CONCLUSIONS:

The Stealth is a very nicely designed mini-cooler, good looking and able to do some real cooling. However, dust buildup could be a real problem over time so I would suggest a monthly vacuuming to keep the Stealth at peak performance. Whether this is worth almost $24 to you is your decision – a little pricey, but active cooling of all heat sources is not a bad thing and it really looks cool. TennMax makes some efficient coolers and this is no exception.

Skip will do a test with the Stealth on a Voodoo board so stay tuned.

Additional reviews with nice pictures:

BX Boards
Tweak 3D

TennMax

After I posted this review, I received the following Email from TennMax:

“I can see you are a creative person, just as many of us at TennMax. We are a bunch of scientists and engineers with accumulated hundreds of years of thermal management experience. Experience covers materials development (inventions), metallurgy (metal extrusion), thermal testing and others. BTW, Lasagna Multileaf design is a world-wide patented idea owned by TennMax.

I appreciate your comment posted. However, I have to say that you have misused the Stealth V3 Fighter Cooler which is specifically designed for cooling the Voodoo3 boards. Please tell the reader this fact – Stealth V3 Fighter is designed only for Voodoo3 cards.

The mounting holes and push pins, the thermal phase change interface pad, and the size of cooler is all specifically designed to fit perfectly for the Voodoo3 cards. If you or others plan to use the cooler for other applications, including use with Peltier element or on a AGP chipset. We have other approaches. We also have other designs which can fit on many TnT2 cards, including Hercules Dynamite TnT2 Ultra.

Let us know what you need or want to do, we may create the exact cooling solutions for the specific applications. TennMax provides consolidated thermal solutions for electronics, not just another company merely marketing fans! BTW, the phase change thermal pad is an excellent and exceptional material to be used under high pressure and at very high temperature (over 100 C!). It is a new class of thermal phase change interface material. Unlike the grease and waxy compounds, TennMax T-Pad is consistent, will not flow or dry up under all conditions. It is also very different from other grayish graphite pad you have seen in the market.

Lasagna has lots of great usage beyond cooling graphics chipsets or AGP chipset, including for industrial computers, laser generators, power chipsets, and many many others.

Keep in touch and you are welcome to explore new use of our innovative coolers.

Vincent Tzeng”


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