CPU, RAM & VRAM Resources
One thing's for sure: DiRT 4 doesn’t put much stress on our quad-core processor, regardless of graphics preset. The High setting does utilize more CPU resources than Ultra. That's to be expected, though, given a higher frame rate and less work for the GPU to do.
Out of curiosity, we wanted to see if changing the game's artificial intelligence setting influenced CPU utilization. DiRT 4 offers four levels of AI, and to spice things up we changed the test sequence to a rallycross course with five other vehicles on the track.
Two observations jump out: CPU utilization is slightly higher with this type of sequence (and five other vehicles present on the circuit), and the AI difficulty level has no appreciable impact on processor utilization.
System Memory Usage
The GeForce cards impose a little more system memory use than the Radeons, but the difference is modest. Also, changing detail levels has no effect on this measurement.
With these values, it is of course necessary to subtract the amount of RAM used by the operating system and its services (around 1.9GB). DiRT 4 is therefore rather economical when it comes to memory utilization.
Video Memory Usage
Even though there is between 6 and 8GB of memory available to the cards in this test, Codemasters' game engine uses markedly less video memory. Perhaps that's the fault of textures with too-little detail.
Furthermore, the GeForce cards have less of their on-board GDDR5 used than the Radeons, though both achieve graphically equivalent results.
MORE: Prey Performance Review