Introduction

In October 2010, AMD released their Radeon HD 6850 and HD 6870 which are based on the Barts GPU core. Today AMD adds a third Barts-based model to their lineup in form of the Radeon HD 6790.

HD 6790 comes with an odd model number that we haven't seen from AMD before. It basically means "the fastest midrange card. In terms of performance we can expect significantly reduced performance compared to the HD 6870 and HD 6850, which have 1120 and 960 shaders - AMD's Radeon HD 6790 comes with 800. Compared to the HD 5770 performance should be increased by higher clocks and architectural improvements over Juniper. Price-wise AMD is communicating around $150 for their new Radeon HD 6790 which seems to match with what we have seen on some early postings of online merchants.

The Card

AMD's HD 6790 looks pretty much like its more powerful HD 6850 and 6870 brothers. AIBs will have their own designs pretty much from day one on.


The card requires two slots in your system.


The card has two DVI ports, one full size HDMI port and two mini-DisplayPort outputs. AMD's display output logic is clearly superior to what NVIDIA has to offer at this time. Vendors are free to combine six TMDS links into any output configuration they want (dual-link DVI consuming two links) - and use them all at the same time. AMD has also introduced DisplayPort 1.2 support with their new cards which allows the use of a DisplayPort hub to connect multiple monitors, or daisy chain them together.

An HDMI sound device is also included in the GPU. The HDMI interface is HDMI 1.4a compatible which includes Dolby TrueHD, DTS-HD, AC-3, DTS and up to 7.1 channel audio with 192 kHz / 24-bit output. The new revision also brings support for Blu-ray 3D movies which will become important later this year when we will see first Blu-ray 3D titles shipping.


You may combine up to two HD 6790 cards from any vendor in CrossFire.


Here are the front and the back of the card, high-res versions are also available (front, back). If you choose to use these images for voltmods etc, please include a link back to this site or let us post your article.

A Closer Look

The heatsink cools memory chips and voltage regulation circuitry as well as the GPU.


The card has two 6-pin PCI-Express power connectors which are specified up to 225 W power delivery.


The GDDR5 memory chips are made by Hynix, and carry the model number H5GQ2H24MFR-T2C. They are specified to run at 1250 MHz (5000 MHz GDDR5 effective).


Just like on HD 6850 and HD 6870, AMD is using a CHiL CHL8214 voltage regulator on this card. All major software utilities support this voltage controll for I2C software control and monitoring.


AMD's Barts graphics processor is made on a 40 nm process at TSMC Taiwan. It uses approximately 1.7 billion transistors on a die area of 255 mm². This is also the first GPU to carry the AMD logo instead of the ATI logo.