'Extra rendering threads'

[Artea]

How does this work exactly? I was trying to get Shadow Hearts to run at full fps and a quick search on this forum revealed that it ran faster in software mode. So when I tried that and got only 30 or so fps, I thought it odd, until I realized that I had set 'extra rendering threads' to 3. I reduced it to 0 and my fps was suddenly at a full 60. Which doesn't really make sense, so I I tested it with a different game (Dragon Quest VIII); however, this time setting the amount of rendering threads over 0 did increase the performance.

Obviously I don't plan on using the software mode frequently, but since some games require it, I would like to know more about it. Also, what amount of extra rendering threads should I fill in, assuming each of my cores have one thread each?


My specs are:

Processor: AMD Phenom II X4 N970 (4 x 2.2 Gh)
GPU: AMD Radeon HD 6650M, 1 GB VRAM
6 GB DDR3 Memory

Thanks to whoever takes the time to help me out.

[miseru99]

Optimum = amount of cores -2 soo if you have a quad/4 core cpu, then extra rendering threads at max should be 2. If you use MTvu hack as well in the same time, then one less. This option can give different results depending on game(like pretty much everything else), and if you set too many threads or if you're running something heavy in the background that normally just uses the cores not used by pcsx2 it'll also mean slow down.
Edit: I will also add, that as long as you don't need the extra power, just leave it at 0, couse the gain isn't equal to added cpu weight;P no reason to heat it up too much for games which doesn't need it, same for MTvu.

[pcsx2fan]

I just googled "Extra rendering threads" and found this thread.

When GSdx Software Mode in use,
one thread for pcsx2 program, another thread for GSdx Software Mode, this happens for typical dual core cpu which has no HT support i.e. 2 cores 2 threads or 2C/2T, In other words 2 threads is permanently occupied in software mode, you see the default value of "Extra rendering threads" is 0 to take care of dual core cpu of 2 cores 2 threads.

e.g. an AMD quad core cpu is 4 cores 4 threads you set the value to 4 - 2 = 2, If enable MTVU then set the value to 2 - 1 = 1
e.g. an Intel quad core cpu with HT is 4 cores 8 threads you set the value to 8 - 2 = 6, If enable MTVU then set the value to 6 - 1 = 5

Code:

formula with MTVU = threads - 3
formula without MTVU = threads - 2

I can see the name "Extra rendering threads" is named by Technical Perspective, that's why normal user got confused as the 1st post.
Unfortunately this also confuse me so I post this post to clear my head Something about "Extra rendering threads" should be written into Official English Guide for PCSX2 1.0.0

[miseru99]

Actually I would update my words from few months ago, the optimal amount heavilly depend on a game and the usage of other cores:3. In other words, there is no formula for any best setting.

[EmucraZ]

i have an i3 intel cpu i think has HT but i can use 3 threads in software mode and MTUV but it still works fine but i get an extra 20 fps speed up but how is it not slowing down or crashing or becoming buggy?

[abdo123]

MTVU is useless in SW mode because the bottleneck is GS and any cores working on it would be much better than giving it to EE

[Squall Leonhart]

MTVU is NOT useless in software mode

by splitting some of the VU load off, the GS plugin has more cycles available to it.

[abdo123]

i am not getting it who can he process extra cycles if he barely doing the already available ones ...

[pcsx2fan]

i have an i3 intel cpu i think has HT but i can use 3 threads in software mode and MTUV but it still works fine but i get an extra 20 fps speed up but how is it not slowing down or crashing or becoming buggy?

I guess if you set "Extra rendering threads" to 2 or 1 and still use MTVU, you'll get more FPS.
P.S. All generations of i3 by now is owning HT i.e. 2 cores 4 threads

Even I set the value to 16 it doesn't crash my Windows XP FPS slowdown though