X-bit labs

S3 GammaChrome S18 Pro Graphics Adapter Review (page 2)

Category: Video

by Alexey Stepin

[ 04/19/2005 | 07:19 PM ]

Closer Look

The GammaChrome appears to be a complex device, with numerous small elements scattered all around its deep-blue PCB. Like the GeForce 6600 GT, the GammaChrome has a 128-bit memory bus, but the former works at much higher clock rates. So, why all this complexity? The S3 engineering team may have encountered instability in the operation of the graphics card and had to make the wiring of the PCB more complex. If it’s true, this fact also explains why the company has so far refused to launch the GammaChrome S18 Ultra whose core was going to work at 500MHz.

The power circuitry is, however, simple, since the GammaChrome isn’t a very hungry consumer of power. The card doesn’t carry additional power connectors. The back side of the PCB has even more small components than the front side: there are four more memory chips here with all their accompaniments as well as the load-bearing elements of the power circuit. Besides that, you can see the S3 Graphics and the PCI Express logos here.

The graphics card offers the usual selection of connectors: D-Sub, S-Video and DVI-I, the latter provided by a TMDS transmitter from VIA (the VT1632A chip, which supports resolutions up to UXGA or 1600x1200). The S-Video output is actually a universal connector that display devices with S-Video, RCA or YPbPr inputs can be attached to, via a special splitter.

Our sample of the S3 GammaChrome was ventilated with a modest aluminum cooler with a small fan and a sticker with the company’s logo. Very thick white-color thermal paste was the thermal interface. The fan doesn’t have a tachometer and doesn’t seem to be controlled depending on the temperature. This cooler seems to be appropriate, considering the low power consumption of S3’s graphics processors, but the final version of the GammaChrome is going to bear a bigger cooler. The small cooler on our sample was fastened with two standard plastic spring-loaded clips and concealed the heart of the device – the GammaChrome processor.

As you see, S3 followed the example of ATI and NVIDIA and switched to the open-die type of packaging. The size of the graphics core is small as it contains only four pipelines. The marks on the chip say this sample of the GammaChrome was manufactured the second week of 2005, i.e. in the middle of January. There’s a traditional protective frame around the chip to prevent the cooler from misaligning and the core from chipping.

The graphics card bears eight 256Mbit GDDR SDRAM chips from Samsung with an access time of 2.86 nanoseconds. This means the chips are rated for 350 (700DDR) MHz frequency and that’s exactly the frequency they are clocked at on this card. The chips remain rather cool at work, so we don’t consider the lack of heatsinks on them as a drawback.