X-bit labs

MSI RX2600XT Diamond 512 Graphics Card: A Jewel of HD 2600 XT Carats (page 3)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko

[ 10/19/2007 | 09:16 AM ]

PCB Design and Specifications

The PCB of the RX2600XT Diamond 512 follows the reference design developed by ATI for Radeon HD 2600 XT GDDR4, but MSI used a red rather than black solder mask, which endowed the device with such an imposing appearance. Exclusive products are usually colored like that.

Like the reference card, the RX2600XT Diamond 512 features a complex power circuit based on an uP6201AQ controller. Some of the elements are not installed, which means that the circuit can be scaled up for newer, more power-hungry, processors. This is also indicated by the fact that the PCB allows installing a standard 6-pin connector for additional power supply. Here, this connector is missing and its seat is occupied by an electrolytic capacitor. Having a power draw much lower than 75W, the graphics card receives all the power it needs from the PCI Express slot. The power circuit is sharply separated from the main part of the PCB, meaning that ATI follows the modular design principle not only when developing GPUs but also when developing PCBs.

Since this version of Radeon HD 2600 XT GDDR4 is equipped with 512 megabytes of graphics memory, it has four memory chips on the reverse side of the PCB, which you don’t often see on modern graphics cards. The card carries a total of eight GDDR4 chips (Samsung K4U52324QE-BC09, 16Mbx32, 1.8V). The chips have a rated frequency of 1100 (2200) MHz but are clocked at 1150 (2300) MHz by the card. Although each chip has a 32-bit interface, the total width of the memory bus is 128 bits, the standard value for the RV630 chip.

The graphics processor has a standard configuration with 120 ALUs grouped into 24 universal shader processors, 2 texture and 1 raster processor which are equivalent to 8 TMUs and 4 ROPs. The RV630 is weaker in this respect than the G84 that has 16 TMUs and 8 ROPs. In fact, the superiority of the GeForce 8600 GTS over the Radeon HD 2600 XT GDDR4 comes from this advantage whereas in sheer computing power the Nvidia card is far inferior to the ATI one. The GPU of the RX2600XT Diamond 512 is clocked at 850MHz which is 50MHz higher than the frequency of the standard Radeon HD 2600 XT.

Save for the described peculiarities, the RX2600XT Diamond 512 is identical to the reference ATI Radeon HD 2600 XT GDDR4. It has two DVI-I ports with dual-link mode, a universal VIVO port, and CrossFire connectors. The VIVO functionality is not supported, though. The appropriate chip is not installed on the PCB, although the latter has a seat for it. As opposed to some other versions of Radeon HD 2600, the reference PCB design doesn’t provide for the installation of a HDMI connector instead of one DVI.