Does that mean that the CPU is responsible only for the game calculations (positions, memory adresses, collision detection and so on) and all video rendering is done by the GPU? I always thought that video rendering is still done mostly by the CPU because GPU usage was much harder to implement.
Quote:Does that mean that the CPU is responsible only for the game calculations (positions, memory adresses, collision detection and so on) and all video rendering is done by the GPU?
Yes.
Quote: I always thought that video rendering is still done mostly by the CPU because GPU usage was much harder to implement.
No. The entire history of GPUs and graphics cards has been a history of slowly moving more and more stages of the graphics pipeline (rendering tasks) off of the cpu and onto the GPU. We've reached the point where nearly all of the graphics pipeline is implemented entirely in hardware (GPU).
Unfortunately, there are no active used listings for the 6870 card near me right now.
I could get a XFX HD 5870 for 100€, though. In benchmarks, this card has always performed better than its successor. It has a lower tact rate (850 vs 900 MHz), but more steam processors (1600 vs 1120).
1) What is better for Dolphin, more steam processors (->5870) or more tact rate (->6870)?
2) Does 5870 perform as well as 6870 on the driver side, or are there issues like with the 7000 series?
3) Are there Dolphin builds that can utilize the 7000 cards (I'm thinking of either 7770 or 7850) properly yet?
1) Afaik both is not really important. Dolphin just needs a GPU with a high VRAM bandwith and a high amount of GFLOPS. (Plscorrect me NaturalViolence, if I'm wrong
thanks!) But, of course, newer GPU work more efficient due to the better microarchitecture.
2) There should be no problems afaik, I never heard of any problems.
3) There are still some problems with the Direct3D11 backend, but the Direct3D9 backend runs just fine. Here's a thread about it ->
http://forums.dolphin-emu.org/Thread-radeon-hd7000-series-extremely-bad-performance-in-dolphin-d3d11-backend
1: Clock rates, number of SPs, and microarchitecture are all equally important in determining shader throughput (GFLOPs) which in turn is one of several specs that determine GPU performance. Another major one is video ram bandwidth like DefenderX mentioned.
3: The issue you refer to has been resolved with the latest drivers.
Thank you all for your helpful replies, I've settled for a used XFX 6870 dual fan for 96€.