Welcome, the Shiny NV40!
The GPU die will undoubtedly thrill you with delight when you see it: it is huge! This is the price they had to pay for the tremendous number of transistors (220 million). The GPU die surface contacts the heatsink directly, because there is no protective lid on it, like in case of NV35 and NV38. They probably did it to improve the heat dissipation.
The GPU has a mirrored surface and the edges are protected with a special framing which prevents the heatsink from moving the wrong way. This is not a new solution, as ATI has already used it for their RADEON 9700 PRO. Our particular GPU sample was manufactured on week 12, 2004, i.e. about 4 weeks ago that is why we can call our GeForce 6800 Ultra a young boy :) Actually, our GPU worked at a relatively low core clock: when we activated CoolBits in the drivers, the core was reported to be working at 400MHz. It is lower than the core frequency of the NV38, but we shouldn’t consider high working frequency a must for high performance, as NV40 architecture is much more advanced than that of the previous generation solution: NV38.
Simplify the PCB Design
The PCB has mostly changed in the right part where the power circuitry is. The device consumes much more power than its predecessors, so some elements of the circuitry are covered with a small passive heatsink. The high-capacity capacitors are pretty few to our surprise. There are only four of them here, while the GeForce FX 5950 Ultra has five. Although the PCB carries quite a bit of SMD-capacitors, so I wouldn’t call the power circuitry of the new GeForce 6800 Ultra simple, especially keeping in mind the PSU requirements.
Anyway, the PCB design of GeForce 6800 Ultra is much simpler than that of GeForce FX 5950 Ultra or any other high-end solution from NVIDIA.
A small buzzer is evidently part of the security system and informs the user about overheating, fans failure or about the lack of power and so on. Tyan took a similar approach in its graphics cards, and we have already seen how efficient it is sometimes. Two power connectors are firmly fastened with a metal loop soldered to the PCB; they are marked as Primary and Secondary.
There are two DVI-I connectors at the left part of the PCB and the TV-out is placed unusually. This solution makes perfect sense considering the growing popularity of LCD monitors. If you’ve got a monitor with an analog input, you can attach it via a simple adapter included with the card.
The back side of the PCB doesn’t have additional memory chips as GDDR3 allows amassing the necessary 256MB with eight chips only. I would like to draw your attention to the memory wiring: it is pretty complex as it works at 550 (11200) MHz. Actually, the front side of the PCB may seem somewhat empty to you, because locating the memory chips on one side allowed moving a lot of other components to the bottom of the PCB. In particular, the additional TMDS-transmitter from Silicon Image as well as the whole lot of other smaller components has been also moved to the reverse side of the PCB.
The metal plate at the back serves for fastening the cooling system and preventing the PCB from damage. The cooler is attached by spring screws so that you didn’t crush the board by screwing them up too tightly.
The place where the connectors reside is interesting, too. As you see, each landing place has two connectors of DVI-I or D-Sub type. This means that the card may come in the following versions:
- Two DVI-I connectors;
- Two D-Sub connectors;
- One DVI-I and one D-Sub connector.
The last version will surely be the most popular of all, but the first variant may be appealing for some users, too. Overall, the PCB and the cooling system of the new card are not a revelation. Although the PCB differs from that of GeForce FX 5950 Ultra, there are some similarities, too. As for the cooling system, NVIDIA has recently been drawn to snail-shaped fans, while heat pipes are a logical solution considering the heat dissipation of the NV40.
The PCB design seems pretty smart, save for the two power connectors, which should both be used. That is not the most convenient solution, as you will need one extra PSU connector, which you don’t always have available (that depends on your system configuration). On the other hand, you’ll probable have to buy a new powerful PSU for your new NV40-based graphics card and such PSUs usually have enough Molex connectors. By the way, NVIDIA doesn’t recommend using power splitters.