thanks!
Well, in the Ishiiruka forum i have solved the problem! I don't know which is the parameter tha caused the issue, but with these initial settings on Ishiiruka, issues are disappeared:
in the first enhancements tab:
Internal resolution 3x
Antialiazing NONE
Aniso 1x
Ubershader: Disabled
Filetreing and culling : Naive
Scaled EFB Copy Enabled
Texture Scalling Off
Hacks Tab:
Stored efb copies to Textures Only checked
Texture cache acuracy fast
External Framebuffer : Disabled or virtual
Bounding Box: Disabled
FastDepth Calclation checked
Full Async Shader Compilation Checked
In the Advanced Tab
Compile Shaders On Sttartup Checked.
Then, i tried to enhance the filters and this is the final results on my current pc:
1) I have tried with Resolution 1080p, Anti-Aliasing 8xMSAA and Anisotropic 16x and games still are fully at 60fps!!!!!
2) Then i tried 1080p, 2xSSAA and 8x Anisotropic and games are fully at 60fps. With 1080p, 4xSSAA and 8x Anisotropic sometimes there are slowdowns in some specifict points (from 60 to 40/45fps). And with 8xSSAA slowdowns are in the same point but more evident (from 60 to 30 fps).
So probably SSAA requires more resources. In any case probably the problem wasn't my cpu/gpu, there wat another parameter that caused the issue...
I tried similar settings on regular Dolphin (Ubershader: Disabled of Ishiiruka is equivalent to Synchronous in Dolphin i think): slowdowns are disappeard, but freezes are occasionally present

For sure isn't a problem of CPU/GPU because fps are always at 60...but the games for an instant sometimes freeze.. i don't know why...