Cooling the X1950 XTX
One of the chief criticisms Radeon X1900 XT and XTX end users had with their cards was the noise level produced by the boardís heatsink/fan unit. Quite frankly, at full tilt the cardís fan was unbearable. Fortunately, if you kept your case well-ventilated with good airflow the fanís RPMs never had to hit top speed, even when running with two cards in CrossFire mode, but the X1900 XT still ran noticeably louder than competing cards from NVIDIA such as the GeForce 7800 GTX 512MB and the GeForce 7900 GTX. Many Radeon X1900 XT/XTX owners swapped the stock ATI heatsink/fan unit out for aftermarket coolers, while Sapphire equipped their X1900 XTX Toxic board with a water cooler from Thermaltake to resolve this issue.
For the Radeon X1950 XTX, ATI took these complaints to heart, developing a brand new redesigned heatsink/fan unit that incorporates heat pipe cooling for the first time in a desktop ATI graphics card.
At the heart of the Radeon X1950 XTXís cooler lies a copper heat pipe. Inside the heat pipe is a liquid coolant, usually distilled water. As the GPU begins to heat up, the liquid in the heat pipe begins to boil, forcing hot vapor to the other end of the heat pipe where it is cooled. From there the vapor condenses back to the liquid phase and returns to the other end of the heat pipe. This cycle is continually in motion, working to keep the graphics core cool.
In practice, weíve found that heat pipes can do an extraordinary job of keeping CPUs and GPUs cool, which is why theyíre used so frequently nowadays on aftermarket coolers, but the downside is theyíre so effective at transferring heat off the component in question that they tend to carry a lot of heat themselves. Therefore, in order for the heat pipe to be most effective, itís usually used in concert with a large heatsink or a large fan, or a combination of both as we see on the GeForce 7900 GTX. In fact, NVIDIA uses four heat pipes on the GeForce 7900 GTX. Unlike NVIDIA, ATI uses copper rather than aluminum for their heatsink and heat pipe (although NVIDIA uses a copper base plate that rests directly over the GPU on the 7900 GTX). Copper is used because of its superior thermal conductivity in comparison to aluminum. Basically, NVIDIA uses more heat pipes which are also larger than ATI, but ATI attempts to get around this by employing copper throughout their cooling units, rather than NVIDIA, which is predominantly composed of aluminum.
Wrapped around all this is a ducted fan enclosure. Itís responsible for taking the heat that comes off the heatsink and heat pipe and blowing it outside your systemís case. NVIDIAís system also blows some air outside the case, but NVIDIAís system also blows air out the right side of the card as well. Itís not a fully enclosed system like ATIís.
In operation, ATIís new heatsink/fan unit works quite well, running noticeably quieter than the Radeon X1900 XTX cooler, in fact it even runs quieter than NVIDIAís GeForce 7600 GT and 7900 GT reference boards, but itís still not as quiet as the GeForce 7900 GTX. Itís a good cooler though and to demonstrate its effectiveness we tried to record audio clips of the cooler in action while running looped 3DMark runs, but the cooler ran so quietly that we couldnít record any good clips even with the microphone set at a distance of 10Ē. Like the X1900 XTX, the PCB of the X1950 XTX carries a lot of heat, so you may want to ensure that you've got adequate airflow blowing across the board, but other then that we were quite pleased with the new ATI cooler.
The rest of the X1950 XTXís board design is pretty similar to the Radeon X1900 XTX. Interestingly enough, ATI uses only six Pulse PAO511 inductors on the X1950 XTX, versus seven on the Radeon X1900 XT/XTX (including the X1900 XT 256MB), while VRM circuitry is now cooled by a copper heatsink versus the aluminum heatsink that was used previously on the XTX. In addition, ATI continues to provide VIVO support with the Radeon X1950 XTX, with this functionality being provided by ATIís venerable Rage Theater chip, while high-bandwidth digital content protection (HDCP) support is integrated for the first time in a desktop Built By ATI graphics card. Previously this feature was exclusive only to ATIís high-end FireGL workstation cards. A limited number of ATIís board partners have also released HDCP-compliant graphics cards, but these were limited to the less powerful Radeon X1600 Pro GPU.
Price and availability
Weíve been told by ATI that the Radeon X1950 XTX will carry an MSRP of $449, and should be hitting retail shelves next month on September 14th. In addition to Built By ATI cards, ATIís lined up all the usual suspects in terms of board partners, so expect to see boards from ASUS, Connect3D, Gigabyte, GeCube, HIS, MSI, PowerColor, Sapphire, and others shortly.
Before we begin to discuss the performance offered by the Radeon X1950 XTX, itís important that we go over image quality. To address this topic weíve created a dedicated article on this subject which can be found here. In the article we take a look at ATIís various AA modes (including adaptive AA) as well as their AF, comparing it to NVIDIAís GeForce 7900 GTX.