The Radeon HD 7970 3GB Graphics Card
Okay, we have talked about the architecture and the features it brings to the table quite enough. Let’s dive into the hardware itself, the brand-new Radeon HD 7970.
Based on the 28nm Tahiti GPU, the Radeon HD 7970 includes 2048 stream processors all running at 925 MHz core speed. There is a total of 3GB of GDDR5 (you read that right) running on a 384-bit memory bus and clocked at 1375 MHz.
The Radeon HD 7970 3GB is nearly identical in size to the HD 6970 though with a new cooler design that keeps the attractive red/black color combination. Nothing beats the sexiness of the Radeon HD 5870 to us, but we have moved on. The reference cooler has a piano-finish gloss finish to it that picks up fingerprints and is a pain to photograph, but chances are you won’t have that problem.
The connection panel on the card includes a single dual-link DVI connection, full-size HDMI connection as well as a pair of min-DisplayPort…ports. In the box you will find both an HDMI to DVI-I and mDP to DVI-I adapter so you should be able to get up an running with at least two monitors out of the gate. Yes, the requirement that one of your monitors run off of a DisplayPort connection (or an actively adapted DP connection) in order to push three monitors total.
Notice that AMD has included a full slot of bare grill for better movement of air from the across the GPU and out the back of the case rather than exhausting inside your chassis. This helps keeps temperatures down though the fan is just a bit louder than the HD 6970 was before it.
The fan and heatsink design have been modified as well including a new fan with wider blades that move more air. AMD claims that this offers both "improved cooling and acoustics" though in my testing the HD 7970 was marginally louder than the HD 6970. The heatsink is again of a vapor chamber design with more fins directed for air to flow smoothly out the back of the card.
The HD 7970 will require both an 8-pin and a 6-pin power connection to run at its stated board power.
These cards will continue to support 2-, 3- and 4-way CrossFireX implementations should your budget permit. Also, the dual BIOS toggle switch makes a return though in this case it doesn’t really do much on the reference cards. Card vendors will be able to implement overclocked settings if they want down the road, but we’ll have to wait to see retail cards for that.
Surprisingly, all 3GB of frame buffer are located on the front of the card under the heatsink – no memory is found on the back of the HD 7970.
This here folks, is the first PCIe 3.0 ready connection we have seen. It doesn’t mean much to us yet and its looks pretty much identical, but there you have it.
The Radeon HD 7970, as we discussed on the previous page, will go into its deepest idle state consuming less than three watts of power. Anyone that tells you discrete GPUs are going to add to your electric bill now are simply denying the facts.
AMD promises quite a bit of headroom over the default 925 MHz – in our testing we were able to run at 1025 MHz without an issue!
The above specification table puts things into perspective for you if you are more of a numbers enthusiast. With 64% more transistors, the HD 7970 is much more complex chip though it fits inside the same 250 watt TDP that the Radeon HD 6970 did. Performance increases pretty much across the board with the exception of the ROP count and pixel fill rate – we’ll leave it to the benchmarking to see if that might become an issue.