PCB Design, Technical Characteristics, Cooling System
The NX8500GT uses a reference PCB as is indicated by the Nvidia mark, but the card is obviously assembled on MSI’s own facilities because it employs a red solder mask.
The G86 consuming even less power than the G84, the power circuit is very simple here. An additional power connector is missing as the load capacity of the PCI Express slot is going to be more than enough for this graphics card. The wiring of the PCB is rather sophisticated, though, due to the use of DDR2 memory.
Hynix HY5PS56162A chips are organized as 16Mx16 and have a capacity of 256Mb each. Eight such chips provide a total of 256MB of graphics memory accessed across a 128-bit memory bus. The chips work at 1.8V voltage and have a rated frequency of 400 (800) MHz. This is the frequency the chips are indeed clocked at by the card, in compliance with Nvidia’s official specifications.
The die area of the G86 chip is considerably smaller in comparison with the G84 as you can expect considering the smaller amount of transistors, 210 and 289 million, respectively. There is no protective frame around the die, just like on G84-based cards. Our graphics card carries a revision 300-A2 G86 chip dated the 4th week of 2007. The GPU contains 16 unified shader processors, 1 TMU with 8 address and 8 filter units, and 8 raster operators. The official GPU clock rates of the GeForce 8500 GT model are 450MHz and 900MHz for the main and shader domain, respectively, but the real frequencies are 459MHz and 918MHz due to the specifics of the clock generator.
Like the reference GeForce 8500 GT, the MSI NX8500GT lacks a MIO connector, but supports SLI technology, even though we doubt many people will use this opportunity. The two cards communicate via the PCI Express bus in SLI mode.
The card has one DVI-I port and one D-Sub port. It also offers a 7-pin mini-DIN connector for display devices with analog video inputs (S-Video, RCA or YPbPr).
The GPU is cooled by a simple round cooler with circular ribbing.
Its “copper” color shouldn’t deceive you: the cooler was milled out of a chunk of aluminum and then painted. The heatsink is blown at by a small translucent fan with a 2-pin connection. It is almost silent because the G86 doesn’t need much cooling. The cooler is secured on the PCB with two plastic spring-loaded clips.