Dolphin, the GameCube and Wii emulator - Forums

Thought I would post an update. My speed problem was related to two things.

#1 My graphics drivers, which you guys warned me about.

#2 RAM. My HTPC only had a single stick. I completely forgot that a couple of months ago I had taken out a stick for testing on another machine and didn't put it back in. I finally noticed this yesterday when I fired up htop and it reported only 4GB of RAM, I thought, "that's not right, I had 8GB..." I put the other stick back in and there was a significant speedup. Dual channel helps .

Now the A8-7600 plays Mario Kart at 60 fps easily at stock settings on my 1080p TV. I can bump it up to 1.5x native resolution and still get 60 fps. I cannot do 2x or any anti-aliasing, but that's fine by me, being able to play at 1.5x native resolution is enough of an improvement for me. It gets better though....

I had an old A4-4000 AMD APU lying around so I decided to test that. I wasn't expecting much because it's a lower spec. APU. However I was pleasantly suprised to see it play Mario Kart Wii at 60 FPS at 1.5x native resolution! The FPS can sometimes dip below 60. At the opening of the racing scenes it can sometimes drop to 30-40 but during the race it stays at 57-60 fps. As wtih the A8-7600, I wasn't able to do any anti-aliasing without a significant fps drop (this was expected though). Anyway, I think this is very impressive performance on such a low spec APU.


The specs on these two APUs are...

A8-7600, 3.1 GHz, 3.8 GHz Turbo, 384 GPU cores at 720 MHz (Kaveri)
A4-4000, 3.0 GHz, 3.2 GHz Turbo, 128 GPU cores at 720 MHz (Richland)


One final question... The A4-4000 does well at 1.5x NR, but the A8-7600 does better. Is this performance due more to the CPU speed or the number of GPU cores? I'm guessing CPU speed since I see over and over that emulation is a CPU intensive process, but I just thought I'd ask

The thread title says:

(03-06-2015, 11:15 PM)necbot Wrote: [ -> ]AMP APU

(LOL)

(03-06-2015, 11:15 PM)necbot Wrote: [ -> ]I can't get anywhere near this kind of speed.

To get the most out of your APUs, you must use MS Windows (Win7 x64 is fine) and the Direct3D backend.
D3D11 is so much faster than OpenGL it's not even funny (especially with the latest 14.12 'Omega' drivers).

(03-06-2015, 11:15 PM)necbot Wrote: [ -> ]One final question... The A4-4000 does well at 1.5x IR, but the A8-7600 does better. Is this performance due more to the CPU speed or the number of GPU cores?

CPU speed.

(02-27-2015, 06:35 PM)degasus Wrote: [ -> ]btw: where did I use the name "Markus" ?

On your GitHub page.

Hate to play necromancer but I had some information about running Dolphin on Arch linux using the open source drivers. In my earlier posts I complained about the slow speeds of the open source driver and about how I got it to work when I switched to the proprietary drivers (catalyst). Since Arch linux does not support catalyst officially I was always running into issues/bugs with these drivers that could never be resolved.

Eventually, I switched from catalyst to the open source drivers and decided to give up on playing Dolphin on my htpc. I was too much of a hassle and the speeds were too slow on the open source drivers. Then I saw an article about how the open source drivers had vsync turned on at all times but that the catalyst driver did not. I remembered reading a post on this forum about vsync and how it isn't usually necessary and that it decreases performance. In order to turn it off I added this to my ~/.drirc file....


With this the open source driver ran on par with catalyst. 60 fps at 1.5x with the open source drivers is easily achievable. So my speed problem was related to the open source drivers having vsync on at all times. This happens regardless of whether or not it is checked in the dolphin settings menu.

I wanted to add some info regarding RAM and AMD APUs in case others run into the same issue.

I wasn't surprised that adding the other stick of RAM helped performance, since it essentially now runs in dual-channel mode. APU graphics performance are severely bottlenecked by RAM bandwidth, so running with dual-channel RAM essentially increased the bandwidth and gave a performance boost to your iGPU.