Test Setup and Methodology

Using the CPU stress-test utility S&M v1.90 the processor was run under 100% LOAD. Temperatures were monitored using both Core Temp 0.95 and Intel's TAT or Thermal Analysis Tool (zipfile). The processor was tested at it's default speed 8x266FSB = 2130MHz, then at the highest overclock attained at default Vcore; 8x400FSB = 3200MHz and finally the highest stable overclock under S&M, which was 8x450FSB = 3600MHz at 1.40Vcore. Thermal Throttling, Speed Step and EIST were disabled in the BIOS. These exact conditions were then repeated with the Alphaool NexXxos XP WB and the stock air-cooler provided by Intel with the Retail E6400

Intel Socket-T Test System
CPU	Intel Conroe 6400 SL9S9 L624A851
Mainboard	1.) Asus P5W DH Deluxe/WiFi (BIOS 1901) 2.) Gigabyte P965-DS3 (BIOS F12)
Memory	1.) Crucial Ballistix Tracer PC2-5300 (2x1GB) 2.) Mushkin X8500 DDR2 (2x1GB)
Graphics	Leadtek 7950GX2
Power Supply	PCPower&Cooling 1KW
Cooling	1.) Sub Zero CPU waterblock 2.) Alphacool NexXxos XP 3.) Stock Air cooler Alphacool NexXxos Pro II Radiator 2x PABST 4412 FG/4L fans 73CFM OASE 1500 12V ~ 24V DC-pump with Adjustable DC box 10mm ID tubing
Storage	2x Seagate Barracuda 80GB SATA Perpendicular
Optical	Plextor PX755-SA DVD/RW SATA
Video Monitor	Samsung 930b 19"
Operating System	Windows XP

Clicking on the thumbnails below will show screenshots taken to record processor temp, speed and voltage during LOAD tests with the Sub-Zero installed.

8x266FSB 1.320Vcore | 8x400FSB 1.320Vcore | 8x450FSB 1.40Vcore


In the charts below IDLE essentially describes the system with very few active programs running. Although just snapping the screenshot with Mirek's freeware utility MWSnap will load the CPU slightly. I had to repeat the step five or six times to capture the lowest temp. Again this is indicative of the accuracy of internal thermal diodes. While many criticize their accuracy and the accuracy of the software reporting temps, as chip-makers rely on such devices for TM2 and other features their reliability is critical.



LOAD is arguably a difficult concept to measure since no-one can really say what a full-load should look like to the processor. Stressing the processor with Orthos and similar programs does raise the temp although in most cases it exceeds what your processor will ever see. In that respect such programs are similar to synthetic benchmarks since very few people would continuously run that program on their PC. Where crashes normally appear in the "real world" usually occurs during heavy 3D applications/games. I used to run Seti@Home and S&M to mix things up, however; I've found S&M which targets specific processor areas is the most rounded and certainly able to raise temps as high as any other software. Except for the 8x450FSB level of testing where 87% was the highest the processor could endure without crashing, all other tests were run at 100%.



Conclusive Thoughts

Sub-Zero represents a new level of excellence among Watercooling.de’s catalog. The block competed with and even out-performed the NexXxos XP which is considered to be one of, if not the best 10mm based water block on the market. Watercooling.de will integrate the Sub-Zero into a single 120, dual 120 or triple 120-radiator based ExodusFlow kits with a LAING DDC-pump. At this point the only other water block I might recommend to compare against the Sub-Zero would be the Masterfrezzer M-II. Today, the Sub-Zero takes the "Brass O-Ring."

PRO
Excellent performance.
Great Ergonomics.
Design improves slightly from high flow.
Works with all current and older platforms.

CON
Not available in the USA

Sub-Zero can be found at the Sub-Zero Shop Watercooling.de

I would like to thank Florian J. for the sample and his patience.