Gainward CoolFX PowerPack! review

No-one's denying that they're a headache to install, but if you're going to try and overclock your components to the limit, water-cooling systems are one of the best ways: witness the Waterchill CPU cooler (see issue 107, p283). Where the Waterchill was a processor-cooling system, Gainward's CoolFX PowerPack! goes for your graphics card's jugular instead.

To avoid all the mucking about from retro-fitting graphics coolers - the Zalman and Thermaltake devices we looked at last month (see issue 110, p297) are prime examples of this - the CoolFX system comes with a graphics card pre-fitted: a Gainward GeForce FX 5900 Ultra. The immediately apparent thing about this, of course, is that the FX 5900 is no longer the most current nVidia chipset, having been superseded by the FX 5950 Ultra last month (see issue 110, p86). However, given that the 5950 is a relatively minor revision to the 5900, the CoolFX isn't necessarily a dead duck.

Effective though the Waterchill was, the whole thing was a bit rough around the edges, all sorts of hoopla and extra mains cables being required to make it go. The CoolFX is more refined and doesn't rely on being directly connected to mains electricity: both the pump and radiator fan simply take 12V power from the PC's power supply via standard molex power connectors. This also eliminates the need for the control box of the Waterchill, giving you one less thing to worry about.

And finding space will definitely require some worrying. The radiator will fit into the space normally used by front-panel 5.25in devices, but you'll need four bays free to accommodate its height. Likewise, the pump will sit on the floor of your case, but unless you've got a lot of space you'll be in trouble, since the water tubes need ample room to avoid kinks or folds.

The process of putting it all together is pretty easy. All that's required is to cut the single length of tubing supplied into three appropriate-length pieces for connecting the pump, radiator and card-mounted heatsink together in a closed circuit, push it all together and prime the pump. The pump itself is an Eheim unit, normally used for aquariums. They have a good reputation for reliability among the leagues of fish-fanciers, so there shouldn't be any worries on that score. This is just as well, since there's no mechanism for detecting a pump failure.

One thing that becomes apparent when installing the graphics card is that not all the components are water-cooled: the layout of a 5900 Ultra is such that the GPU and half the RAM chips are on one side and the rest of the RAM is on the other. The second lot of RAM has no direct connection to the water-cooling system, relying purely on a standard passive heatsink, meaning the memory can't be clocked as high as might otherwise have been managed.

The default clock speed settings for the CoolFX are higher than a standard 5900 Ultra, with a 500MHz core clock speed and 450MHz (900MHz effective) DDR memory clock. Results from overclocking were initially interesting and show that it's not always straightforward. Upping the GPU/memory clocks from 500/900 to 515/980 resulted in a decrease in performance in some tests, with the 3DMark03 Mother Nature test dropping from 3,752 to 3,705. Altering the settings down to 515/975 gave a boost of around 200. In the end, the fastest setting overall was 520/975. The erroneous results probably stem from asynchrony between the clock speeds, resulting in GPU wait states.

In comparison with the Creative 3D Blaster 5 FX5950 Ultra, the CoolFX performs better in some non-DirectX 9 tests, both at 500/900 default settings and overclocked to 515/975. But in the areas that really matter - namely, the DirectX 9 tests performed by 3DMark03 and real-world gaming at high resolutions with anti-aliasing and anisotropic filtering - the CoolFX is behind the newer nVidia chipset and well below the scores of ATi's new Radeon 9800 XT (see issue 110, p86).