Technical Specifications and Power Consumption

Just like the majority of ATI Radeon HD models, Radeon HD 4770 supports up to four cards in CrossFireX configurations. The dual-card configuration is of primary interest to us, because it is the most affordable option that doesn’t require a specific mainboard with three of four PCI Express x16 slots. The specifications of a tandem like that look pretty impressive:

Click to enlarge

Click to enlarge

Its computational power, RBE and video memory subsystems performance are almost twice as good as those of Radeon HD 4670 CrossFireX. And considerably higher frequencies of the graphics cores will most likely make up for the fewer ALUs and texturing processors compared with Radeon HD 4850 X2. Our today’s hero doesn’t look bad against the background of Nvidia solutions, either. However, it is fairly hard to make any assumptions here because of architectural differences between the computational units in ATI and Nvidia graphics cores. Moreover, TMU and RBE performance in Nvidia graphics cores is theoretically higher; however, as we all know, it doesn’t always guarantee victory in games. Therefore, we would like once again to refrain from making any assumptions at this point and wait for the results of our benchmarks instead.

The combined power consumption of two Radeon HD 4770 graphics cards is another trump of this CrossFireX configuration: it makes only 99W, which is solely due to fine 40nm manufacturing process. It is just a little higher than the corresponding reading of the Radeon HD 4670 CrossFireX tandem, and moreover, looks absolutely remarkable against the background of potential competitors, such as Radeon HD 4850 X2, for instance.

I would like to remind you that the actual numbers may be different from what you see above. First, we don’t yet have the ability to measure power consumption of two graphics cards working in a multi-GPU configuration, so the 3D readings are obtained as the power consumptions of single graphics cards added together. And secondly, even in 2D mode the power consumption of the secondary card never drops down to 0. Nevertheless, the numbers above are precise enough to give you a good idea of Radeon HD 4770 CrossFireX power consumption levels. At least, we can say with all certainty that you won’t need a high-capacity PSU for that.

Well, Radeon HD 4770 HD CrossFireX configuration looks very promising in theory. Now let’s see if it proves up to our expectations in practical tests.