Configuration of my home sutdio

Virus Usb out is 44.1 Khz To 48 Khz
Virus Analong OUT is up to 192 Khz

Usb Quaity is almost fine for home studio.

Zitat von Fermax

1) if I use a Plug in (instr or effect or else) with the Virus ASIO driver the performance (or polyphony) of the TI2 is worst?

The functionality of the Virus as a soundcard does not take away much (if any) of its processing power. What it does take away is its ability to act as a destination for sidechaining.

Zitat von Fermax

2) If I connect every instrument to a audio interface (as MOTU 828mk3 Hybrid) what are the advantages in term of sound (and Polyphony)?

Polyphony is a characteristic of each and every instrument by itself, e.g. a standard guitar has 6 note polyphony, a flute - only 1. Regarding the ability to record large arrangements, It all depends on your workflow, even if your interface has a limited number of inputs. The workflow is usually to start with a MIDI mockup or a one-shot live recording as a reference track, and then building up the arrangement by overdubbing individual tracks and finally ditching the reference (maybe not all of it since it may sometimes hold a few gems you can't afford to lose). Every one will come up with their own variation on this workflow. The only limit is your computer's ability to read multiple tracks from the hard drive simultaneously. If you have a large amount of RAM it can act as buffer memory to speed things up. Regarding sound quality, I usually prefer to transfer digitally whatever I can, and use analogue inputs only when I must. Regarding the Virus itself, its sound processing is external to the computer and the only thing you have to worry about is the communication between your computer and the Virus.

Zitat von Fermax

3) What are your suggestions to better have a performance studio (home)?

The most basic advice is to have a dedicated computer only for the purpose of audio recording and production. This way you can remove (or even not install) all the things you don't need and might take away from your resources. There are many web tutorials on how to streamline your computer for audio production. There are many myths and misconceptions in this field so make sure you read everything you can before you do anything.
Hope this helps.

Let me begin by taking things back to the basics:
Your computer has three types of resources which are provided by the hardware you choose, and taken up by the software you use:

• Memory - For storing and retrieving what ever you are working on. For example, you have RAM which is relatively quick, and your hard drive which is slow and stores things in the form of files. Memory is measured in size and throughput.
• I/O (communication) - Lets the computer know what is going on around it, through USB, firewire etc. It is only measured with throughput. All the communication buses are usually aggregated to the PCI bus along with some memory devices - meaning only one device can be handled at a time by the PCI bus, and the PCI bus connects to your CPU's local bus, and shares it with the RAM - again, only one device can be accessed at a time, and that's why the throughput of your PCI and local bus is very important.
• Computing power - How fast can your CPU calculate things such as adding pairs of samples to mix between two channels, or multiplying vectors of impulse response to create a filter.

Now let's see what resources each piece of software is taking:

• Pure VST-s - Usually need no communication resources. The DAW usually handles this for them. Virtual analog VST-s feed only on MIDI which is very lightweight and therefore have very modest memory requirements, but the computing power they require is HUGE. Sample based VST-s require a considerable amount of memory to store and retrieve their samples, and their resampling engines along with their internal effects, require quite a lot of computing power.
• VC, the Virus VST, is not a pure VST. It is only a GUI for the synth engine inside the metal box called a Virus. Therefore it uses a lot of communication between the computer and the Virus using USB. It also uses some memory to store and retrieve your patches on your computer, but not a lot. It doesn't need much computing power.
• Your souncard driver - Usually needs only communication resources, some drivers offer software FX, but they usually can be disabled.
• Your DAW - Needs something from everything, it needs memory for the tracks, computing power for the mixing and communications to know what you want it to do.

Now let's see what happens:
When you add a lot of VST-s you start taxing your computer's CPU. The sound will start to stammer because the computer cannot calculate the sounds in time. The soundcard has nothing to do with it. What do you do then? You "commit" your tracks (some DAW-s call it freeze) - once you are happy with a track, turn it into an audio file that doesn't require as much calculations. You can always come back to it, change and overwrite it, if you keep your original VST track muted.
Going back to the Virus as a soundcard problem, the sidechaining is a VST trick, that can be done with VC. Having a USB synth and a USB soundcard is not a problem in itself, but a communication throughput issue. As I mentioned before, on buses you can only deal with one device at a time. In USB, one internal hub defines one bus. If you connect each to a different internal hub, They will not compete on the same USB bus, and on the higher PCI bus level, PCI is fast enough to deal with both in time. When you add more USB devices to the configuration, you increase your chance for trouble, so maybe get an IT expert to help you find the best way to connect all of your devices.
Hope this helps.

Zitat von flabberbob

…Loads of good advice…

What do you do then? You "commit" your tracks (some DAW-s call it freeze) - once you are happy with a track, turn it into an audio file that doesn't require as much calculations. You can always come back to it, change and overwrite it, if you keep your original VST track muted.

If I can just add a little bit to the excellent advice you have already been given - I'm not sure how things work in other DAWs but in Logic it's useful to mute the regions, if you mute the track but not the regions all the calculations are still being done by the plugins in the channel strip, but you just can't hear the result as you have muted the output. A belt & braces approach would be to mute the regions as well as the tracks, that way any errant pops, clicks or ticks won't be heard & the whole channel strip should now be very cpu friendly yet easy to recall should you ever need to.