Leadtek WinFast A400 Ultra TDH – Bigger, Heavier, Cooler!
The Leadtek WinFast A380 Ultra TDH had a most impressive look thanks to its massive cooling system (see our article called ASUS RADEON 9800 XT and LeadTek WinFast A380 TDH Ultra: The Battle for AquaMark3 for more details). That system was very efficient, so the company continued the same concept in the new A400 series:
As you see, the cooling system has evolved over the times. It has acquired more size and weight and a proper name: 3 Air-Surround Cooling System. The copper heatsink has become larger; it has more ribs and the ribs are longer. But the most important thing is of course the flat heat-pipe that transfers heat from the GPU area to the side sections of the heatsink. The material of the casing is different, too. It is now deep-brown plastic rather than metal. The seemingly useless “wings” at the top part of the casing do have a purpose. At least, the right wing directs airflow at the heatsink that cools down the power circuitry of the graphics card.
The 60mm fan of the 3 Air-Surround cooling system has a non-standard geometry of the blades: the curve of the blades is opposite to the rotation direction. This design solution helps to spread the air stream on the sides of the heatsink rather than underneath the fan. Well, there are a few ribs under the fan, too. Overall, the efficiency of the cooling system is high – it would probably handle a junior Athlon XP model or a Celeron.
The protective grid has changed, too. Instead of the thin and flexible wire carcass, we now have a stiff, “bulletproof” lattice with numerous small holes. Coupled with a relatively high rotational speed of the fan, this version doesn’t provide for a noiseless operation, although Leadtek claims the cooling system to produce no more than 28dB of noise. As before, a portion of the air stream from the fan is driven to the backside of the PCB where a massive copper heat-spreader is placed:
We were surprised at first, since no GeForce 6800 series card should have memory chips at the backside of the PCB. What is that heat-spreader to cool? We found out, however, that the BGA-packaged memory gives out quite an amount of heat through the chips’ legs, i.e. it heats up the backside of the PCB! The graphics processor also contributes to this, so the PCB has to be cooled down by a heat-spreader. The surface of the PCB is rather complex there, so there are special thermal pads between it and the heat-spreader, which was perceptibly hot during our tests, indicating that the Leadtek engineers were right in their solution.
The cooling system conceals eight GDDR3 memory chips with an access time of 1.6ns manufactured by Samsung. The memory works at the standard (for the GeForce 6800 Ultra) frequency of 1100MHz. Its total amount is 256MB, as should be. The graphics core is clocked at 425MHz – slightly above the standard frequency. As we mentioned at the beginning of this review, the Leadtek WinFast A400 Ultra TDH is an accelerated version of the standard GeForce 6800 Ultra. The higher starting frequency implies a good overclockability of this card, and we will check this out soon.