Articles: Graphics
 

Bookmark and Share

(23) 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 ]

PCB Design and Specifications

We had anticipated that there would be versions of the GeForce 8800 GT with a unique PCB design and the discussed product from Gainward proves our point. Its PCB topology resembles the reference card only at first sight.

 

There are differences even in the left part of the PCB, although they mostly boil down to a different position of some smaller elements and slightly different wiring. The two-pin plug near the MIO connector is missing on the reference card. It serves for an internal SPDIF connection when the audio card or mainboard lacks an external coaxial port.

The power circuit has undergone most changes. It doesn’t resemble that of the reference card at all. Power transistors are grouped into a single block and cooled with one heatsink. Instead of a Primarion PX3544 controller, the three-phase GPU power circuit is governed by a Richtek RT8802A. The memory chips are powered through a Richtek RT9259A instead of a traditional Intersil ISL6549 controller. Like on the reference card, there is only one additional power connector (a standard 6-pin one) because G92-based solutions do not need more.

Examining the reverse side of the PCB we found an error the developer made when designing the Bliss 8800 GT 512MB GS GLH:

There is an additional capacitor near the GPU that should not be there. Perhaps it is a quick correction of some error in the PCB wiring or the choice of component ratings. Such corrections can often be seen in presale samples of graphics cards such as ours. Off-the-shelf samples of Bliss 8800 GT 512MB GS GLH are going to be free from that.

Like GeForce 8800 GT 512MB with the reference PCB design, the Gainward card carries Qimonda HYB18H512321BF-10 memory chips. These GDDR3 chips have a capacity of 512Mb (16Mbx32), 2.0V voltage, and a rated frequency of 1000 (2000) MHz. They are clocked at 1025 (2050) MHz on the card, which leaves no room for overclocking. The total amount of graphics memory is 512 megabytes.

Like the GPUs of the graphics cards from Leadtek and MSI we had tested earlier, the GPU of the Bliss 8800 GT 512MB GS GLH is dated the 40th week of 2007, i.e. early October. Its clock rates are increased greatly over the reference ones: the main domain has a specified frequency of 700MHz while the shader domain, 1750MHz. These are higher than the frequencies of the Leadtek WinFast PX8800 GT Extreme. Due to the specifics of the clock generator, the real frequencies are somewhat different: 702MHz for the main domain and 1728MHz for the shader domain. That’s slightly different from the frequencies of the Leadtek, so we can expect the Bliss 8800 GT 512MB GS GLH to deliver about the same performance.

The card is equipped with a standard selection of interface connectors: two dual-link DVI-I ports with support for HDCP and display resolutions up to 2560x1600 pixels, and a universal mini-DIN port for analog video output and for receiving SPDIF signal from the audio card. The MIO connector is necessary for uniting two such cards in a SLI configuration. The card has only one MIO and does not support configuration with more than two GPUs.

 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 ]

Discussion

Comments currently: 23
Discussion started: 12/24/07 02:17:12 PM
Latest comment: 04/08/08 02:58:46 PM

View comments

Add your Comment