 There's been a lot of focus lately on 
how ATi and nVIDIA's mainstream cards only have half the rendering pipelines of 
their high end counterparts. Let's remember something here though, both the NV43 
and R410 have eight pixel rendering pipelines. This is the same number as on the 
Radeon 9800XT, and twice that of the GeForceFX 5950 Ultra, and those cards are 
still pretty darn fast. That should already tell you that performance will be 
good.
There's been a lot of focus lately on 
how ATi and nVIDIA's mainstream cards only have half the rendering pipelines of 
their high end counterparts. Let's remember something here though, both the NV43 
and R410 have eight pixel rendering pipelines. This is the same number as on the 
Radeon 9800XT, and twice that of the GeForceFX 5950 Ultra, and those cards are 
still pretty darn fast. That should already tell you that performance will be 
good.  
   
 Nvidia's GeForce 6600 core is built on IBM's 0.11 micron manufacturing 
process and contains a whopping 146 million transistors. nVIDIA has cut the 
vertex pipelines from the six found in the GeForce 6800 class cards to three in 
the GeForce 6600. To economize further, the memory controller has also been cut 
in half to 128bit. That means at high resolutions with AA/AF enabled, the NV43 
will not be able to handle things as well as its more expensive 
sibling.
 There are two 
models of the NV43, the GeForce 6600GT and plain GeForce 6600. The Albatron Trinity 
GeForce PC6600U that we're testing now is based off the Geforce 6600 and has a 
core clock speed of 400 MHz, and memory running at 700MHz.  
 
Twin Videocards with nVidia
 
SLI 
 One of the 
most exciting features of the Albatron Trinity GeForce PC6600U is support for 
nVidia's SLI (Scalable Link Interface, not Scan Line Interface as 3dfx called 
it) technology. What this means is with a compatible motherboard, you can run 
two PCI Express GeForce 6600 videocards in 
parallel! In theory this will potentially double the raw rendering power of the 
system.  
 SLI today is 
different than it was back in 1998 when 3dfx released the Voodoo2. Back then, 
two Voodoo2 cards would each work on half the image to be rendered. The primary 
card would render all even lines of the resolution while the secondary card 
would render the odd lines. 
 nVIDIA does 
things a bit differently. One card renders the top half of the image and the 
other card renders the bottom half. These cards are linked together with a 
U-shaped connector that comes with the motherboard. 
  At the 
moment you can only SLI videocards of the same class, for example two GeForce 
6600s or two GeForce 6800 Ultras, but not a 6600GT and a 6800 class card. 
Whether or not you'll be able to SLI lower end cards with higher end cards in 
the future is still unclear, but I wouldn't bet on it.
At the 
moment you can only SLI videocards of the same class, for example two GeForce 
6600s or two GeForce 6800 Ultras, but not a 6600GT and a 6800 class card. 
Whether or not you'll be able to SLI lower end cards with higher end cards in 
the future is still unclear, but I wouldn't bet on it. 
 Heatpipe technology and the passive 
heatsink
 The Albatron Trinity GeForce PC6600U is 
one of the few mainstream-performance videocards on the market to be cooled by 
heatpipe technology. Before we look closely at the cooler on this videocard, 
let's talk a bit about heatpipes in general.
  A heatpipe 
is sealed copper tube which absorbs heat from one side (the source) and moves it 
to another location in an effort to cool off the source. The thermal transfer is 
achieved thanks to a working fluid (usually water) that is vacuum sealed inside 
a copper tube.
A heatpipe 
is sealed copper tube which absorbs heat from one side (the source) and moves it 
to another location in an effort to cool off the source. The thermal transfer is 
achieved thanks to a working fluid (usually water) that is vacuum sealed inside 
a copper tube.
   With a lower 
atmospheric pressure inside the tube, the working fluid will become vapour at a much lower 
temperature if one side of the heatpipe is heated. This is plain old physics at 
work - the lower the air pressure, the lower the temperature needed to boil water. 
When one end of the copper heatpipe starts warming up by the heat of the GPU, 
the working fluid inside the heatpipe will absorb that heat energy and convert from 
liquid to vapour. 
  As the working fluid changes phases, 
it absorbs the latent heat energy and carries it towards the 
cooler end of the heatpipe. Once the vapour reaches the cooler side, it 
releases its heat energy into the copper tube, and consequently condenses back into liquid 
form.
     As the working fluid changes phases, 
it absorbs the latent heat energy and carries it towards the 
cooler end of the heatpipe. Once the vapour reaches the cooler side, it 
releases its heat energy into the copper tube, and consequently condenses back into liquid 
form.
        The cooler end of the heatpipe is connected to 
a standard heatsink, which then transfers the heat it has absorbed from the 
heatpipe into the surrounding environment (air). The newly condensed working 
fluid is then drawn by capillary action through an internal wick structure 
inside of the heatpipe back towards the hot end, and the entire process repeats 
itself.
 This system 
seems to work extremely well with the Albatron Trinity GeForce PC6600U. The 
heatsink on the rear of the card was often as hot as the heatsink on the front 
where the VPU is, and the small rear fan enables the card to quickly release the 
waste heat.