Question regarding Enable Dual Core and Vsync

[magus]

Hello all,

I recently downloaded the latest development build of Dolphin yesterday and was playing Super Mario Galaxy. I was testing the settings to see which works best for my computer. I read in another thread where it mentions to uncheck enable dual core to see if there was an fps boost. Doing this gave me about a 10 fps boost(which is a lot imo).

I noticed that the enable dual core option is checked by default in Dolphin. Are there certain CPU's (i3, i5,Amd) where leaving it checked is the better option? Or does it vary game by game? I have an i7-7700K. Was just wondering if there was a pattern or whether it affected only cpus with hyperthreading, etc?




Also sorry for the double question but can someone explain the differences between using vysnc in Dolphin vs my Nvidia vysnc. I noticed that using vsync in Dolphin causes slowdowns of 10-12 fps in certain parts whereas enabling it under Nvidia did not have those slowdowns. To note, both vsyncs got rid of the screen tearing.

[Helios]

It's actually rare when unchecking dual core gives you a speed boost.

There are a few possibilities why here.

1. Your OS was somehow being insane and scheduling the hard working threads poorly. I don't see Win10 doing that often.

2. Your OS was being confused at the very low workload Dolphin asks for compared to what your top end CPU can do, and clocked down accordingly. Turning off DC mode increased usage of one thread enough to clock up the CPU.

3. You hit an odd workload in Dolphin that is actually faster on single core mode. This can happen periodically in certain games. JMC47 knows more about this possibility.


As for why nvidia's vsync is faster, no clue. Honestly, Dolphin's v-sync is kinda crappy. I'd just use your vendor's driver implementation.

[JMC47]

Dolphin's vsync lacks stuff like triple buffering, so, it's probably just better vsync on the GPU.

[magus]

So I think the reason why Enable Dual Core was slowing down my game was because Super Mario Galaxy is one of those games that has EFBAccessEnable = True in its default ini. It seems like for games that have that setting it is better uncheck Enable Dual Core.

Picture of my CPU and GPU usage with Dual Core enabled (Ran at 35 FPS):

   

Picture of my CPU and GPU usage with Dual Core disabled (Ran at 42 FPS):

   

Picture of my CPU and GPU usage with EFBAccessEnable taken out and Skip EFB Access turned on under hacks.
So with Skip EFB Access turned on, there was no difference in FPS between Enable Dual Core being on or off(Ran at 46 FPS). 

   


Here is the thread where Helios mentioned disabling dual core to the guy who was having problems with Skyword Sword(a game with EFBAccessEnable = True) and it fixes his problem.

https://forums.dolphin-emu.org/Thread-best-dolphin-settings?page=2