NVIDIA GeForce FX 5800 Ultra Graphics Card
The new GPU from NVIDIA comes into our test lab on the NVIDIA GeForce FX 5800 Ultra reference-card:
Looks impressive, doesn’t it? While the PCB is quite homely, the cooling system is a monster made of copper and plastic:
Because of this cooling system, the card takes up two compartments in the system case: two brackets at the backside of the chassis. One of the brackets will have VGA, TV-Out and DVI outputs; the other – air in- and outtake vents.
The cooling system of the graphics card consists of two parts: the front side features an active cooling solution for the GPU and some of the graphics memory chips. The backside has a heatsink that covers the rest of the graphics memory chips.
The active cooling system of the GPU and memory is based on thermal pipes. They take the heat from the core and memory chips and transfer it to the heatsink:
The foot of the cooling system is equipped with special pads for tight thermal contact with the memory chips and also a layer of some supple material: thermal interface for the graphics core:
The heatsink that covers the backside of the card also carries such thermal pads. They are about one millimeter high.
A centrifugal blower, similar to the one used by ABIT in its OTES cooling solution (see our article called “Overclocker’s Dream: ABIT OTES Review”), pumps the air through the cooling system heatsink:
This fan is the main noise source of the working GeForce FX 5800 Ultra. The card has already earned the nick-names like “hair-drier”, “vacuum-cleaner” and the like for this loud and irritating noise. It is truly the most unpleasant issue about it. The fact that the fan only starts up in 3D applications doesn’t save the day: people buy these cards exactly for 3D, not for work in office applications. By the way, this noise from the working card is nothing compared to what you hear when the fan slows down. You see, the control circuitry doesn’t slow down the fan smoothly by reducing its rotation speed to a halt. It seems that the card doesn’t reduce the voltage sent to the fan little by little, but sends recurrent pulses of full voltage changing its on-off time ratio step-by-step. As a result, the rotation frequency of the fan collides with the power impulses sequence frequency, there arise beats and pulses and the card sets up a rich sound performance that could have waken 3dfx back to life :).
What is all this mess about? They just wanted to take off the heat from 125 million transistors of the graphics core:
The frequency of the GeForce FX GPU is 500MHz, which is more than 1.5 times higher than the frequency of the main competitor: ATI RADEON 9700 PRO. Of course, such high clock-rate is the outcome of the finer manufacturing technology. For example, the frequency limit for the 0.15micron R300 chip lies somewhere around 400MHz. In order to increase the frequency of its chips higher, ATI will have to go over to the finer technology process sooner or later. NVIDIA has already carried out the transition.
It’s a meaningful fact that NVIDIA didn’t use a 256-bit DDR memory controller in GeForce FX. Instead, there is a less complex 128-bit DDR II controller, which allows reaching higher frequencies. This new memory type has been developed to work at high frequencies and we can see it in GeForce FX 5800 Ultra: the graphics memory of the card is clocked at 1000MHz (500MHz DDR). The resulting peak bandwidth of the 128-bit graphics memory bus of GeForce FX 5800 Ultra is 15.2GB/s, which is just a little lower than the 18.9GB/s of the 256-bit bus of RADEON 9700 PRO.
But back to the card. It carries eight DDR II 2ns chips from Samsung:
These chips heat up a lot: after a few minutes of work, you can’t touch the heatsink at the backside of the card, it’s very hot. Considering that the backside heatsink is not forcedly cooled by any air streams, we might say that a chassis with good airflow is one of the requirements for GeForce FX 5800 Ultra to work stable.
NVIDIA GeForce FX 5800 Ultra, just like RADEON 9700 PRO based cards, requires additional power supply. But unlike them, GeForce FX 5800 Ultra can work even when there is no additional power supplied. In this case, the working frequencies of the card are reduced to 250MHz chip and 500MHz memory.