Water vs. Air cooling: Corsair Hydrocool 200 EX and Koolance EXOS
Since I've been descending into geekdom, might as well go all the way, the current rage is to water-cool your CPU. Since heat is the biggest enemy when overclocking, folks have been using exotic cooling to get much better performance. If you nitrogen cool your Pentium for instance, you can get to 4GHz from a stock 2.4GHz part. Pretty neat. Some interesting sites to study:
* "Overclocking.com Reviews":http://www.overclockers.com/articles373/. An interesting set of reviews that compares performance of air-cooled vs. water-cooled. Most interesting result is that water cooled systems aren't orders of magnitude more efficient. For instance, the Corsair "Hydrocool":http://www.overclockers.com/articles373/waterkit.asp is the current watercooling kit leader at $215 for the kit. It cools at 0.22C/Watt (that is for every 1 watt of CPU power, temperature rises 0.22 degrees Centigrade) at 57dBA, in comparison, the Thermalright "SLK900":http://www.overclockers.com/articles373/socketA.asp which is the current leader in air colling for AMD is the same 0.22C/W. Now it is very loud at 74dBA (for comparison, really quiet is the Thermaltake Silentboost at 21dBA). The big benefit is really that it is more efficient and quieter but at a higher price and complexity. With a reasonable noise level of say 50 dBA, for instance the Volcano 11+ runs at 0.44C/W, so it is half the efficiency at equal noise levels.
* They also point out that the higher the case temperature, the hotter the unit. My case is about 30-35 degrees C, so that's why people put in case fans, to try to get the temperature down, so its all about differentials. Most folks though won't run their CPUs absolute maxed out at 100 percent CPU utllization even when playing games, so even a quiet fan isn't too bad as long as the machine isn't stressed.
Looking in more depth at the Corsair, here are some reviews:
* "Corsair Hydrocool 200":http://www.overclockers.com/articles746/. This seems to be a good compromise kit. Made by corsair, so you don't home brew it. Nice interface system and its self contained, plus good performance.
* "Fast Lane":http://www.fastlanehw.com/reviews.php?action=view&revid=89. Main note is that it won't work with Athlon 64 yet (:-(). good performance.
* "Nordic Hardware":http://www.nordichardware.com/reviews/cooling/2003/CorsairHydrocool/. Similar review and evaluation. Pricier than DIY, but works well and easy to install.
* "Mod The Box":http://www.modthebox.com/review264_1.shtml. Review from Canada, they basically like the installation ease of the unit and it was decent at temperature, but loud for a watercooled system.
* "HardOCP":http://www.hardocp.com/article.html?art=NDUxLDM=. They tested it against the EXOS and like the EXOS better. Better cooling and better waterblock apparently.
For the Koolance, these folks have been around for a while:
* "Mod The Box":http://www.modthebox.com/review200_1.shtml. Liked the unit better than the Corsair. You do need to buy the waterblock extra and the waterblock from Koolance was flat and hard to fit. Good performance.
* "HardOCP":http://www.hardocp.com/article.html?art=Mzc2. They liked this much better than the Corsair. Cooled about 4 degrees Celsius better.
* "Pimprig":http://reviews.pimprig.com/cooling/koolance_exos_alum_and_blocks.php. He does a nice comparison test vs. the Corsair, a ThermalRight SK7 aircool and a home-brew system. Unlike HardOCP, he found the EXOS and Corsair have about the same performance. But it is much quieter and it has two pumps so it is more fail-safe.
* "Monkey Review":http://www.monkeyreview.com/reviews/review.php?num=238. Yet another review. He found the setup easy, One point he makes is that the diode in the CPU is up to 30 degrees C higher than the socket diodes normally used for testing. [For instance, my own machine runs at about 47 degrees at maximum from the CPU socket while the CPU diode is reading nearly 77 degrees, so there's your 30 degree difference]. Most of the benchmarks on this page are run against the CPU socket not the actual on-die thermister (only late model Barton Athlons have it apparently).
* "The Wizards":http://www.the-wizards.com/catalog/. They sell the EXOS for $199 plus another $35 for a CPU-200G cooling block