Zalman VF1000 LED Graphics Card Cooler

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Our test procedure is an in-system test, designed to determine whether the cooler is adequate for use in a low-noise system. By adequately cooled, we mean cooled well enough that no misbehavior related to thermal overload is exhibited. Thermal misbehavior in a graphics card can show up in a variety of ways, including...

  • Sudden system shutdown or reboot without warning.
  • Jaggies and other visual artifacts on the screen.
  • Motion slowing and/or screen freezing.

Any of these misbehaviors are annoying at best and dangerous at worst — dangerous to the health and lifespan of the graphics card, and sometimes to the system OS.

This sturdy modified LX-6A19 (D8000) case from Cool Cases became our test system housing.

Test Platform

Measurement and Analysis Tools

  • ATI Tool version 0.26 as a tool for stressing the GPU and to show GPU temperature
  • SpeedFan version 4.33 to show CPU temperature
  • Seasonic Power Angel AC power meter, used to measure the power consumption of the system
  • A custom-built variable DC power supply to power the system fan and VGA heatsink fan
  • Bruel & Kjaer (B&K) model 2203 Sound Level Meter. Used to accurately measure SPL (sound pressure level) down to 20 dBA and below.

System airflow is quite good, allowing the CPU and system fans to run at close to inaudible speeds (~21 dBA @ 1m with no GPU cooling fan) without compromising system cooling. The intake is about the size of a 120mm fan. The only restriction is an air filter. A much more restrictive cover for the filter was removed because it impeded the airflow too much.

The one and only intake...

...and the same view, with the bezel removed.

There is only one point of exhaust: The 120mm case fan running at 7V. The 80mm fan in the Neo HE power supply was taken out of the picture by using a custom-built duct and vent that supplies airflow only to the PSU — this helps prevent/delay the fan from ramping up.

A fresh air duct isolates the power supply from the rest of the system.

Only one possible point of exhaust: The orange case fan. The fan in the power supply draws its air from a duct that does not interact with the rest of the system airflow.

The airflow in our test rig is typical of an ATX case. Air flows in through the intake near the bottom of the front panel, and is pulled up to the top rear corner. Most of this air will bypass the expansion cards altogether, but a small amount will be pulled across the rear of the card as it is pulled towards the CPU heatsink and the case fan. All of the air will exit the case via the exhaust fan.

The air will flow from the lower right to the upper left, drawing a small amount of air across the VGA card.

The heatsink was installed on a Radeon X1950XTX — a high-powered video card that features a thermal sensor built into the GPU core. The accuracy of the sensor is unknown but we can use it as a point of reference for comparing other VGA coolers in the future (this is the first time we are using this card).

The test procedure was simple. ATI Tool's artifact scanner was run to stress the graphics card with the GPU temperatures monitored by ATI Tool and CPU temperature by SpeedFan. ATI Tool was left running until the GPU temperatures stabilized at which point, readings were recorded. The procedure was repeated at various fan speeds.

Ambient conditions during testing were 18 dBA and 21°C.

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