RADEON X1600 XT
The RADEON X1600 XT is much smaller than the senior models, its PCB being comparable to the RADEON X700 PRO in size.
The card has a seat for a Rage Theater chip, but the chip itself is missing, unlike on the RADEON X1800. It’s probably up to the graphics card manufacturer to put a VIVO chip on this card, and the standard version of the RADEON X1600 XT will come without VIVO functionality. Like the RADEON X1800 XT/XL, the RADEON X1600 XT is equipped with two DVI-I and one S-Video connector.
The RADEON X1000 architecture comprises several independent units, so the RV530 chip differs from the R520 not only in having fewer pixel and vertex processors. The new mainstream solution from ATI also has fewer texture-mapping units, render back-ends and Z-compare units. The maximum number of simultaneously executed threads of shader code is reduced from 512 to 256, too. The resulting chip turned to be compact and economical.
The power circuit of the RADEON X1600 XT is simple if you compare it with that of the RADEON X1800, and consists of fewer elements. Some of these elements are grouped in the top right corner of the PCB, but the switching transistors are located at the left part of the card and at an angle of 45 degrees relative to the GPU. The RADEON X1600 XT uses two programmable PWM controllers RichTek RT9232 (both located on the reverse side of the PCB) to control the power supply of the GPU and memory, respectively. Also on the reverse side of the PCB there is a seat for an additional TMDS transmitter and a cooler’s back-plate.
The memory chips are placed in the traditional way, but again only on the front side of the PCB. The card carries four Samsung K4J52324QC-BJ12 chips (the same chips as installed on the RADEON X1800 XT). Four 512Mbit chips mean 256MB of memory and the memory bus width is 128 bits since the chips have a 16Mx32 structure. It’s not quite clear why ATI put 1.25ns chips on this card – they could have used cheaper K4J52324QC-BJ14 chips (rated for 700 (1400) MHz) since the specified memory frequency of this card is 690 (1380) MHz. We suspect that the expensive chips are only employed on engineering samples, while off-the-shelf RADEON X1600 XT cards will come with cheaper memory.
The cluster-like architecture and the 0.09-micron tech process helped to reduce the RV530 die almost to the size of the RV380 (RADEON X600) – and still squeeze 12 pixel and 5 vertex processors into it! That’s impressive. The chip is hardly older than the R520 installed on our RADEON X1800 XT. It was manufactured during at the 36-th week of 2005, and the text “Eng Sample” indicates that this is probably not a final revision. The GPU packaging is not equipped with a protective frame, as on the RADEON X1800, but it is not very necessary since the cooler on the RADEON X1600 is lighter than on the RADEON X1800 XT/XL.
The cooling system of the RADEON X1600 consists of a copper foundation with soldered-up ribs under a black plastic casing. The configuration of the fan blades differs from the classic fan of the RADEON X800 XT card: the straight vertical blades are driving the air stream sideways from the fan which is the most optimal solution for the employed cooling system. The fan is connected to the PCB with two wires and there is no tachometer (which is present on the RADEON X1800 XL). The RADEON X1600 XT uses a simplified fan-speed control algorithm. The casing of the cooling system bears no pictures like those you’ve seen on the top-end models – maybe this is just not the final version of the card? The fan will probably be noisy at high speeds.