X-bit labs

Leadtek WinFast PX8800 GTS 512MB Graphics Card Review (page 4)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko

[ 02/07/2008 | 01:04 PM ]

PCB Design and Specifications

High-performance solutions from Nvidia used to be manufactured at contracted facilities at the company’s request and GeForce 8800 GTX/GTS cards could not come out with a unique PCB design. It’s different with G92-based products. We have already seen versions of GeForce 8800 GT based on non-reference PCBs, particularly from Gainward, but the first wave of GeForce 8800 GTS 512MB is going to be mostly based on the reference design. The Leadtek WinFast PX8800 GTS 512MB is a typical representative of this first wave:

The card looks more imposing than the Nvidia GeForce 8800 GT thanks to the cooler that resembles the one that used to be installed on GeForce 8800 GTX and old models of GeForce 8800 GTS. The cooler has dual-slot form-factor, of course. The card has the same PCB as the GeForce 8800 GT, though:

The GPU of the Nvidia GeForce 8800 GTS 512MB containing more active subunits and working at higher clock rates, the power circuit has been reinforced and now has all the four phases working. The GPU and memory are powered via Primarion PX3544 and Intersil ISL6549CBZ controllers, respectively. The power connector is a standard 6-pin PCI Express 1.0 plug with a load capacity up to 75W.

Like the Nvidia GeForce 8800 GT 512MB, the Leadtek WinFast PX8800 GTS 512MB uses Qimonda HYB18H512321BF-10 memory that is rated for a voltage of 2.0V and a frequency of 1000 (2000) MHz. The real frequency is lower at 970 (1940) MHz providing a bandwidth of 62GB/s across a 256-bit memory bus. Qimonda chips rarely work at frequencies above their rated one, so there is not much hope for good overclocking.

Like with the GeForce 8800 GT, the GPU is revision A2. This sample is dated the 45th week of the last year, i.e. November 4-10. The main domain frequency is 650MHz, the shader domain frequency is 1620MHz. These are the reference frequencies of GeForce 8800 GTS 512MB. Considering that the GPU has all its 128 shader processors and 32 TMUs active and working, we can expect the new card to be as fast as the GeForce 8800 GTX/Ultra or even faster. The amount and/or bandwidth of the memory subsystem is the only potential bottleneck because the number of ROPs cannot be a limiting factor in modern applications as you can see in tests.

The left part of the PCB is exactly like that of the Nvidia GeForce 8800 GT. The standard configuration implies two DVI-I ports, so the card doesn’t have a chip that would support the new DisplayPort interface. This sample of the card cannot transfer S/PDIF audio over HDMI, but there are places on it for the appropriate components including an internal S/PDIF connector, so we are surely going to see GeForce 8800 GTS 512MB with support of this feature.

Besides the DVI ports the card has a universal 7-pin mini-DIN connector for analog video output in Composite, S-Video and YPbPr format. This feature isn’t very important nowadays. As opposed to GeForce 8800 GTX/Ultra, the GeForce 8800 GTS 512MB doesn’t support triple-SLI configurations as it has only one MIO connector. Although this card is going to deliver high performance, multi-GPU systems are not as popular as to make the developer redesign the PCB to support triple-SLI.

Using the same PCB design, the new card differs but little from the reference GeForce 8800 GT 512MB. In fact, the single difference is the additional phase in the power circuit. The cooling system is a much more interesting thing.