AMD recently rolled out its latest RV790–based card running at 1GHz, and the reason why this card is so special is obvious – the dream of 1GHz on your graphics card is now a reality. This GPU is the central point of the Radeon HD 4890 and its GDDR5 memory helps in achieving 1.6 TeraFLOPs.
Let us recap – the RV790 core has been announced in the beginning of April 2009, and it quickly found its place in AMD’s best single GPU graphics card. The RV790 runs at 850MHz, which is a significant improvement over the HD 4870’s 750MHz. Of course, the HD 4870 comes from a generation of GPUs that was announced in June 2008.
The difference between these two cards, the RV770 and RV790-based ones, is at a glance quite insignificant and is evident only in the higher MHz-count, but note that the core went through some significant changes allowing it to run at 1GHz. The specs say the RV790 has 22sq.mm larger core and 3 million transistors more, which is not a lot of added transistors compared to the RV770’s 956 million. As was the case with RV770 as well, the new GPU features 800 stream processors, 16 ROPs and 40 texture units.
By redesigning the internal structure, the old RV770 core has been adapted for higher clocks. The RV790 core is isolated with a decap ring, used to suppress electromagnetic interference. AMD also made some changes on the power distribution systems, which resulted in consumption lower than on HD 4870.
Being certain that the RV790 will run at higher than 850MHz, AMD decided to showcase its HD 4890 at 900MHz in April and said how the cards will easily run at 1GHz. This was a bit of an unusual step, as we’re used to seeing partners overclock the cards first. AMD encouraged everyone to utilize the RV790’s full potential, and we tried it with three cards but failed in the end. However, many journalists and end-users pulled it off, which means there are good and better RV790 chips on the market.
Now, XFX took the best RV790 chips and created its HD 4890 Black Edition series of cards. These are the first cards running at 1GHz with air cooling and XFX guarantees stable operation at these clocks. You can see the XFX HD 4890 Black Edition specifications below.
We’ve said that the HD 4890 Black Edition is the first graphics card that hits 1GHz with standard air cooling, but its cooling is not great if you like silence. Despite the fact that it keeps the temperatures in check, it gets quite loud.
The DVI outs are red, unlike the reference white ones. Radeon HD 4890 comes with HDMI support, so to connect the card to your HDTV, all it takes is the provided HDMI cable and the DVI-to-HDMI converter. Of course, Crossfire is supported on this card.
The fan is designed to push hot air out of the case, through the grills above the DVI outs. Note that the card is dual-slot.
The card is powered via one 6-pin and one 8-pin power connectors, and as we’ve said in the beginning, this card is more power efficient than the HD 4870.
XFX’s HD 4890 Black Edition 1GHz comes with 1GB of GDDR5 memory distributed on the face of the card, so the back is pretty unpopulated and uninteresting.
The box is compact and tough, and the card comes with HAWX gift game, a popular DirectX 10.1 game