Zalman Reserator 2 Fanless Water Cooling System Review

System Testing

The Reserator 2 was tested on a red-hot Presler 955 CPU and nVIDIA 7800 GTX video card.  The ambient room air temperature was maintained at 23°C ±0.5°C.  The CPU was loaded by running multiple instances of CPUBurn and the GPU was loaded by running rthdribl.exe.

• Zalamn Reserator 2 water cooling system
• Asus P5N32-SLI Deluxe nForce4 SLI Intel edition motherboard
• Pentium Extreme Edition dual core 955 (3.46 GHz at 1.22 Vcore)
• SilverStone ST75ZF 750 watt PSU
• (2) Corsair CM2X512-8000UL  DDR RAM
• nVIDIA 7800GTX 512 MB 550/850 video card
• WD1200JD SATA HDD
• Sony 16X DVD
• Windows XP Pro with SP2
• nForce 91.31 drivers

For comparison, I have included the results from testing with the stock Intel and nVIDIA coolers along with the very capable (but far from silent) Koolance PC4-1025 liquid cooling system.  (Note: the Koolance system was tested with two 7800 GTX video cards/VGA waterblocks, which of course placed a higher heat load on that system.)  The following data is presented for comparative purposes only.  Your actual results may be different depending on the variables unique to your system (CPU, GPU, overclock, ambient temperature, case air flow, temperature monitoring, etc). 

Amb — Ambient air temperature measured with a thermocouple

CPU — Temperature reported by Everest utility using onboard sensor

Tc — Temperature obtained with calibrated thermocouple attached to IHS

Delta T — Fully loaded Tc temperature rise above Internal air temperature

dBA — Sound pressure level recorded 3′ away (background ~30 dBA)

Amb — Ambient air temperature measured with a thermocouple

GPU — GPU temperature reported by Everest utility using onboard sensor

Mem — Video RAM temperature reported by Everest utility using onboard sensor

Env — Video card environmental temperature reported by Everest

Loading both Presler cores with multiple instances of CPUBurn, while using the stock Intel HSF, resulted in significant thermal throttling of the CPU to prevent core meltdown.  However, with the Reserator 2, the CPU cores ran much cooler, so no thermal throttling was necessary and the processors were able to run at a constant 100% load. 

The Reserator 2 silently lowered full load CPU temperatures by 10°C.  I have to admit I was pleasantly surprised to see just how well the Reserator 2 could cope with a fully loaded Presler 955!  The GPU and V-RAM also ran significantly cooler with the Reserator 2 as compared to the stock air coolers.

With an ambient room temperature of 23°C the average water temperature (measured inside the Reserator 2’s reservoir) rose to approximately 32°C at idle and 44°C with the CPU and GPU loaded.  This is obviously a little warm by traditional water-cooling standards and is a consequence of passive cooling.

The most obvious difference when using the Reserator 2 liquid cooling system was the lack of noise.  Both the CPU heatsink fan and video card cooler fan are eliminated.  The only potential source of noise is the small Eheim pump submerged inside the reservoir.  For many, the Reserator 2 will be considered a silent cooling solution, but if you are particularly sensitive to noise, the quiet hum of the pump may be noticeable.