Leadtek Duo PX6600GT TDH Extreme

In the past, we've written quite a bit about the way that SLI works out for gamers. Over time, there have been improvements in the driver and it is now very easy to add your own custom profile for a particular game if there isn't already a profile created by NVIDIA. The list of SLI-optimised games is also growing, as NVIDIA's developer relations team are working closely with game developers to create SLI profiles that will be ready when the game is launched.

Up until now, we've only looked at SLI with two separate cards connected with an interconnect between the two cards. The lower end of the architecture also introduced bridge-less SLI with no requirement for a connection between the cards on the now entry-level GeForce 6600 LE and GeForce 6600.

Not long after, Gigabyte introduced a new way of thinking about SLI with a video card known as the 3D1 - a card with two GeForce 6600 GT's on the same PCB. Today, we're looking at Leadtek's Dual GeForce 6600 GT incarnation, which is said to be slightly more flexible than Gigabyte's 3D1 card. Again, this is two GeForce 6600 GT's located on a single PCB. It's been given a speed bump from the default 500/1000MHz up to 525/1120MHz - a reasonable increase in clock speed over the default GeForce 6600 GT PCI-Express clock speeds.

The cooler is a single slot solution with one large, slow spinning 70mm fan in the centre of the heatsink which is variable speed, dependant on temperature. The heatsink is predominantly black anodised aluminium with the two heat sources covered by a copper insert, which allows for maximum heat extraction from the two GPU cores. The heatsink is secured to the PCB via a large plate on the back, held on by three spring loaded screws and an additional screw. In general the heatsink design is good, efficient and quiet.

You can also see the 256MB of memory located on the card. Strictly speaking, it is two 128MB frame buffers with two 128-bit memory interfaces (one per GPU). It's much easier to consider this card as two separate cards that are simply sharing the same PCB. The video card requires additional power because there's not enough current available for two GeForce 6600 GT's through a single PCI-Express x16 interconnect. However, this seems to have been overlooked as there's no 6-pin PCI-Express power adapter included in the bundle (as you'll see over the page).

The card has a multitude of output options with support for up to three displays when SLI is disabled. The included analogue VGA header is attached to the card using the headers located near the HDTV port. Along with the HDTV port, there are also two DVI ports on the back plate, as we're beginning to see on all of NVIDIA's PCI-Express based video cards.