The Board

Now that we’ve seen the NV40 chip, let's take a look at the reference board itself:

Board Specifications
Board Configuration GeForce 6800 Ultra
Core Clock Rate 400MHz
Pixel Fill-rate 6.4G Pixels/sec
Texture Fill-rate 6.4G Textures/sec
Memory Speed 550MHz GDDR-3 (1.1GHz Effective)
Memory Bandwidth 35.2GB/sec
Frame Buffer Size 256MB



GeForce 6800 Ultra Reference Board

The length of the board is similar to the redesigned 5900 / 5950 Ultra boards. Although it's unclear to see with the heat sink on, and you can see the layout on the back of the board, the memory layout is also in the same arced fashion at the 5900 / 5950 boards, which appears to be NVIDIA's favourite trace routing pattern for high performance 256-bit memory busses.

The sticker on the back of the board marks the RAM being used on this board as Samsung RAM, which we assume is Samsung's K4J55323QF as this is the only GDDR-3 memory they currently display. The speed also shows that the standard operation is 500MHz, though the specifications of 6800 Ultra call for 550MHz memory which indicates that, by default, the reference boards are running the memory with a 10% overclock. 500MHz GDDR-3 RAM does not get that hot, and doesn't necessarily require cooling, so perhaps the cooling over the RAM here is to ensure the overclock remains stable.

This selection of RAM and operating speed may indicate that NVIDIA are hedging their bets on RAM availability. Right now 600MHz GDDR-3 is only just coming into availability, with 500MHz much more available in production quantities. It may be the case that NVIDIA have chosen the halfway point between 500MHz and 600MHz as they should be able to get to 550MHz reasonably easily with 500MHz, but then they can upgrade to 600MHz (potentially leaving board vendors to ship up to those speeds) when they are more freely available.

When we consider that the density of GDDR-3 RAM is greater than the chips used on the NV35 boards and see that all 8 chips required for the 256MB are on the front of the board and none on the underside we can clearly see the board design has paved the way for 512MB variants for the future.

The reference board features two DVI ports and one TV-Out. Two DVI ports make sense for high end, expensive boards such as these, though inevitably it will be up to the board vendors to decide whether they implement them. The NV40 chip features no internal TMDS transmitters though, so board vendors will require an external one for each DVI output they ship with.