Power of water and air combine to form new CPU cooler

WHEN PUSHING YOUR CPU to the limit there are two choices usually, get the best possible air cooling with a top heat sink / fan combo or go for the broke and switch to water cooling. The former are simple to install, but noisy and limited in heat / power capacity, especially with 130W+ CPUs like Intel's Kentsfield when overclocked, even the top ones like Zalman 9700, hit the ceiling with Kentsfield quickly. The latter have substantially greater cooling capacity, but at the cost of installation complexity of pumps, radiators and a zillion pipes, not to mention leakage scares and and, of course, higher cost. Also, since there is no fan present at the CPU socket location, the VRM, North Bridge and memory areas have to be ventilated via additional fans.

Evercool's Silver Knight tries to bridge the gap. It's the first heat sink & water cooler combo for a CPU that I know of. The package box is a bit larger than the largest standard cooler, the afore mentioned Zalman, and much larger than the similarly named Silent Knight from Asus, which is a normal copper heat sink as well. The device itself looks bulky & boxy, but surprisingly light. While the four heat pipes are copper-based, the fins are made of aluminum, and the water cooling side part is, well, plastic.

The combo could function as a standard heat sink even if, for some reason, the water cooling portion fails - the heat pipes and fins are ventilated by a large side fan, which channels the air towards the outflow case fan above the I/O shield. That heat sink functionality is augmented by water cooling tubes which circulate the fluid to and from the heat pipes, providing a 'self-contained water cooling' as Evercool calls it. So, in theory, you'd have a combined air and water cooling system.

The reddish coolant is pre-filled, and the cooling tubes going to the ends of the heat sink's heat pipes are all pre-fitted and set. All you need to do is to fit it on the Intel or AMD CPU socket through an adapter, just like any large standard heat sink, and connect the 3-pin CPU fan cable, that's all.

Is the new cooler more efficient than the usual suspects? I set it up on a challenging platform, an 130 W+ Intel Pentium XE P965, the very last OutBurst of the NetBurst. It's a hot dual-core dual-die 3.73 GHz 1066 FSB monster, running on the Intel D975XBX board, and from the very start I set it overclocked to 4 GHz with 1333 FSB and 12X multiplier, not an easy feat in any case for Intel's Presler series CPUs. The same ran with Thermaltake Golden Orb II just before that, with CPU reaching 67 C even in the BIOS hardware monitor. With Evercool's Silver Knight, the temperature at the same settings went down to 49 C, not bad, but not that much better then the Zalman 9700, which was at 52 C. On the other hand, Zalman's air cooler costs as much as many water cooler, so I can't complain here.

While keeping the same 1.275v CPU input voltage, I managed to bring the speed up to 4.28 GHz with a 1428 GHz FSB - the CPU still ran at around 54 C in the hardware monitor, but Windows couldn't boot at all. After I replaced Intel's lacking North Bridge heat sink with Cooler Master Blue Ice II, an all-copper thingie with a fast fan, the system proceeded to boot, but Windows boot success was truly erratic, by this I mean you're lucky if you get it up every other time.

When I changed the FSB back to 1066 and left the CPU running at 4.27 GHz using a 16X multiplier, the system was fully stable in running Windows, and the CPU was showing around 53 C in the hardware monitor - not bad at all, compared to 51 C from the Corsair COOL high end cooler, and 59 C from the Zalman 9500 at the same CPU and speed. With the integrated fan speed switch, I could reach near-silent operation, which didn't matter to me as I don't play music on benchmark systems, but may be important for the MP3 buffs. Also, the performance on the P965 can give you a good indication of how the thing will perform on the quad-core Kentsfield, since that chip has similar thermal and power demands.

Conclusion
Overall, this new kid on the block has got some interesting technology, decent performance, very quick installation, 10 minutes plus 5 minutes for taking the mobo in and out to mount the bottom supports, and fits well to the board. A full-copper version with a faster fan and a bit more coolant would be welcome as well.

Now, if they could just improve the screw tightening system, the screw locations are hidden deep under the heat sink, and on mainboards with arrays of tall power circuitry around the CPU sockets it is nearly impossible to make use of that hexagonal driver they provide to actually mount and tighten the screws. The fingers got to do the job - small enough to fit in, and thick-skinned enough not to be shredded by sharp VRM heat sinks. I managed it anyway and could still type this story. µ