Right now I have a tascam us 4x4 and I have clicks and dropouts
will a Tascam 20x20 with usb 3.0 fix that?
Or a PCI based system?
I am a bit confused on what may cause any issues?
you can check my system specs as well, I have a pretty nice system
and just installed an SSD getting 440 read and close to that writing speed.
Thanks:)
Take a look at the charts here:
As you can see, you will usually get the lowest RTL (Round Trip Latency) values with a PCIe or Thunderbolt interface.
Unfortunately it’s really hard to say what the cause of pops and clicks is without careful testing.
However, very often it’s caused by device drivers for some of your hardware, in which case a new audio interface will NOT make a difference.
How can I test it?
In the link you posted, presonus studio 192 is the fourth lowest on the low latency chart list. Does it mean, that it performes poorly or great? If the lower it is placed on the list, the worse it performs, then I would have been better of by buying the UR44 from Steinberg performing twice as good, and I would have saved more than 600 dollars… 
Problem is with PCI I have no idea what to get
I like at least 4 mic inputs with XLT and Two inputs for guitar and Bass
I would love a Thunderbolt system, but I’m a PC user
And as of now, no Audio interfaces are working with thunderbolt 3. I think UAD is, but… Whew, pricey!
I also need to research more to find mobos with native thunderbolt
UAD Apollo… 
No UAD:(
I got a UAD Apollo FW and am having nothing but troubles getting it to run without Disabled plugins,RealTime CPU spikes,hi latency. Even using the proposed and particular Firewire 800 card. I ran RME Multiface for 15 years without issue, but new motherboards dont take PCI cards anymore.
This is a bit late but you can use a pcie to pci adapter for rme