Technical Question :P

[metalnumb]

I'm sorry if i asked this before , but it seems that i have to rephrase my question :

-- Why CPU->EFB Access causes so much slowdowns in SMG/SMG2 (at least for me) ? why CPU access to the EFB Copys is that CPU intensive to emulate ?

-- another question : would i benefit from upgrading my CPU into a (Phenom II X3 6MB [L3 Cache] @ 3.8GHZ OC ??)
((specially to help the slowdown of cpu->efb access / also for using LLE on thread)) ??

Last but not least, i love to learn about hardware and i think Emulation is so Exciting ,so please Don't Spare Knowledge

Thanks In Advance !! You Guys Are Awesome

[neobrain]

CPU->EFB access:
The Wii's CPU can directly access the EFB (which is the render buffer of the "GPU"), but in PC hardware we have a strict isolation of RAM and VRAM. Thus, we cannot directly access the emulated EFB (which is just a D3D render target which can be used as a texture) from the CPU. Some textures in D3D are lockable, so that you can at least easily transfer the pixel data from the GPU to the CPU. However, that doesn't work in our case. Thus, we always (for EVERY pixel read from the EFB) have to a) reset the GPU state b) draw a tiny 1x1 square to a lockable buffer texture c) lock that texture so that data can be read by the CPU d) restore the GPU state which is just TERRIBLY slow. SMG only reads sth. like 4 pixels per frame and that's where you can see how slow this feature is from an emulation-perspective. Monster Hunter Tri is even worse since iirc it reads the WHOLE EFB from the CPU...

[metalnumb]

Simplified and Clear Explanation ... Thanks a lot NeoBrain.....
i have another question...Would larger cache capacity helps CPU->EFB access ?
What about the Upgrade ? (The Second Question in my First Post )....

Thanks a Million

[neobrain]

Nope, CPU->EFB access is more likely limited by VRAM->RAM bandwidth and general GPU power...
No idea about the hw upgrade, I'm not really up to date concerning CPU models right now...

[metalnumb]

NaturalViolence once said that it depends on "General CPU throughout" , so i guessed cache capacity was involved
anyways Thnx once again NeoBrain

[NaturalViolence]

I was probably drunk.

[metalnumb]

LOL

[metalnumb]

I Had a Question somehow related to Neobrain's Answer ....
if i want to increase that VRAM->RAM Bandwidth what hardware upgrade should i make ?
Would i benefit from enabling Dual-Channel DDR3 (By adding 1 more Stick)+Upgrading GPU ?
I'm Sorry but im a little Confused (I used google and nothin' about vram->ram bandwidth :/

Thnx........

[metalnumb]

Guys Please Help im very frustrated