AMD spent most of 2012 releasing a slew of 28nm GPUs, starting with the Radeon HD 7970 in January, followed by over half a dozen more cards over the next 8 months.
At the end of the year we launched our feature “The best graphics cards: Nvidia vs. AMD Current-Gen Comparison ", in which Nvidia took out the price range of 100 to 150 US dollars with the GeForce GTX 650 Ti, while AMD claimed the 150 US dollars for itself. $ 200 with the Radeon HD 7850.
As well thought out as the Radeon HD 7000 series was, we hoped 2012 would mark the beginning and end of the series, just as 2011 would mark the previous generation. Expecting anything completely new shouldn't be as we are now three months into 2013 reviewing a brand new AMD graphics card that is not based on a new architecture.
Rather, we have the newest member of the Southern Islands family that aims to bridge the gap between the Radeon HD 7770 and the 7850.
Not the most exciting product to be released, and its performance will be far from what we saw with the GeForce GTX Titan last month. Even so, the new Radeon HD 7790 is likely to be of more interest to many of you than the GTX Titan for the simple reason that it's affordable and should be pretty good value for money too.
The Radeon HD 7790 will be available April 2 for just $ 150. Prices range from 7770 to 7850. Currently, the Radeon HD 7770 is priced at $ 110 to $ 120, while the 7850 costs between $ 180 and $ 200.
When we last checked that the GeForce GTX 650 Ti was the best value in this bracket, AMD seemed to convince us.
Radeon HD 7790 in detail
The Gigabyte Radeon HD 7790 we tested was 19 cm long, a typical length for a modern mid-range graphics card. Gigabyte's own version of the GTX 650 Ti is 23 cm long, although the actual circuit board is quite shorter at just 14.5 cm. This new Radeon GPU core runs at 1 GHz. This is the highest frequency of all Radeon cards and corresponds to the cards of Edition 7770, 7870 and 7970 GHz.
The HD 7790 is clocked 16% faster than the HD 7850, while its GDDR5 memory is also faster at 1500 MHz (6.0 GHz DDR). However, by coupling this frequency to a tiny 128-bit memory bus, the HD 7790 gets a theoretical bandwidth of 96 GB / s, which is actually much less than the old HD 6790.
Gigabyte has overclocked its 7790 card from 1000 MHz to a core speed of 1075 MHz. For this test, however, we clocked the card back to the standard AMD specification of 1 GHz.
The HD 7790 is equipped with a 1 GB image memory, just like the midrange cards of the previous generation. We have no doubt that Board Partners will be releasing 2GB versions. However, since the HD 7790 is not designed for extreme resolutions, 2GB models are unlikely to offer a performance boost.
The core configuration of the HD 7790 is also different from that of the HD 7770. This new GPU has 896 SPUs, 56 TAUs and 16 ROPs. That's 40% more SPUs and TAUs, while the ROPs remain the same.
Gigabyte decided to cool the "Bonaire XT" GPU with its own design that uses a massive 95mm fan. Under this fan there is a relatively small aluminum heat sink with a length of 11.5 cm, a width of 9 cm and a thickness of 2 cm. While that sounds like a decent heat sink, it's actually quite small by graphics card standards.
The HD 7790 works almost noiselessly, as it only consumes 85 watts under load thanks to the ZeroCore power technology and only 3 watts when idling.
In order to supply the card with sufficient power, AMD has a single 6-pin PCI Express power connector – the same setup as the HD 7770, 7850 and GTX 650 Ti as well as numerous other mid-range graphics cards.
Of course, the HD 7790 supports Crossfire, so there are two ports that can be used to connect two cards together. The only other ports are on the I / O control panel. The AMD reference version has a double DL-DVI connector, a single HDMI 1.4a connector and two Mini DisplayPort 1.2 sockets. The Gigabyte version is slightly different in that it uses a pair of DL-DVI connectors, a single HDMI 1.4a connector, and a standard DisplayPort jack.