X-bit labs

The Quick and the Totaled: ATI Radeon HD 2900 Pro Graphics Card Review (page 3)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko

[ 11/26/2007 | 12:01 PM ]

Design and Specifications

Being nothing else but a Radeon HD 2900 XT with a modified BIOS, the ATI Radeon HD 2900 Pro is absolutely identical to its progenitor externally.

There is nothing in this card that you can tell a Radeon HD 2900 Pro by. It uses the same PCB, GPU and memory chips as the Radeon HD 2900 XT.

Our sample of ATI Radeon HD 2900 Pro has 512 megabytes of GDDR3 memory in sixteen 256Mb chips from Hynix (HY5RS573225AFP-1, 1000 (2000) MHz rated frequency, 2.2V voltage). Such chips are also installed on the reference sample of ATI Radeon HD 2900 XT 512MB GDDR3. It is possible that some users will get a Radeon HD 2900 Pro, especially in the 1024MB version, with Samsung memory. The memory frequency is lower in comparison with the Radeon HD 2900 XT: 800 (1600) MHz as opposed to 825 (1650) MHz. The reduction of the memory bandwidth from 105.6GB/s to 102.4GB/s can hardly be noticeable in comparison with the considerable GPU frequency reduction. This parameter looks just splendid against the GeForce 8800 GTS with its 64MB/s bandwidth.

The GPU has 320 ALUs grouped into 64 superscalar computing modules with 5 ALUs in each and capable of processing any type of shaders within the Shader Model 4.0 framework. The core also incorporates 4 texture processors (equivalent to 16 TMUs), four raster back-ends (equivalent to 16 ROPs), and a hardware Compositing Engine for building multi-processor CrossFire configurations. Thus, all the subunits of the R600 chip are active and the single difference between the cores of the Radeon HD 2900 Pro and Radeon HD 2900 XT is the clock rate, reduced from 742MHz to 600MHz on the former card. The gaming tests will show us how this reduction affects the card’s performance.

Like its forebear, the ATI Radeon HD 2900 Pro is equipped with two power connectors: a standard 6-pin PCI Express and an 8-pin PCI Express 2.0. You can insert a 6-pin plug into the latter connector, though. The official overclocking tool available in the Catalyst driver is disabled for the card, but you can overclock it using third-party utilities. The GPU working at a reduced frequency, we can expect the card to have a lower power draw – we’ll check it out in the next section.

The Radeon HD 2900 Pro has two dual-link DVI-I ports with HDMI support (including audio-over-HDMI), one universal VIVO port (supported by the Theater 200 processor) and two standard CrossFire connectors.

The card is cooled by a modified version of the reference cooler that exhausts the hot air out of the system case. We described its design in our first review of the ATI Radeon HD 2000 architecture. The modified version has acquired an additional heat pipe for a total of three. This should improve the performance of the heatsink. This modified cooler is installed not only on ATI Radeon HD 2900 Pro but also on all new Radeon HD 2900 XT cards.

As we know from practice, the cooler’s fan has to work at a high speed to keep the temperature of the Radeon HD 2900 XT within reasonable limits in 3D mode and the card gets quite noisy then. The same is true for the ATI Radeon HD 2900 Pro. The card is almost silent in 2D applications, but becomes distinctly audible in 3D mode – it is no better than the ATI Radeon HD 2900 XT in this respect.