where does latency actually occur?

Hello.
With so many tweak suggestions...changing this or that in windows, in the bios etc, you'd think the whole issue is with windows.
Yet every interface that's sold today boasts 'extremely low latency'.
Ok, so it's a little of both?
Which is more susceptible to causing latency, windows, the daw itself, or the interface?
Of course you would want all three to perform at their peak, but where is it most likely to show up? Which will be the first to show signs of latency?
A less than perfect computer?
A less than perfect interface?

I get that overloading a daw with too many add-ons will break even the best of systems,

So is upgrading to a better interface going to help if you've already maxed out the computer? Or go back to the drawing board and build another computer?

Could you manage better with a less than perfect interface or less than perfect computer.

Sorry if this is on the wrong catagory.

Thanks for any input or ideas.

There's no singular answer to that question, but as a rule of thumb a quality interface (with quality drivers) will perform better on a less powerful system than the other way around, as long as the system is powerful enough to not immediately max out.

Generally speaking, without trying to squeeze every last drop of performance from a machine, every modern mid to high range system you buy can perform well without much tweaking at all.

Regardless of system and interface performance, some plugins cause latency simply by the nature of their process and no amount of computer speed will do much about it. A very simple example is a compressor/limiter with "look ahead" function - one that looks a few milliseconds ahead to determine whether or not to trigger. Unfortunately plugins still can't actually look into the future so what actually happens is that the plugin adds a delay between incoming and outgoing audio and uses the extra milliseconds it gains to perform the look ahead.

There are a few other processes that need extra time. For instance convolution reverbs, linear phase processors (usually mastering EQ), transient designers (basically specialized compressors with look ahead) as well as any pitch correction plugins.

It's really not a simple question as the term "latency" gets thrown around in several contexts. It's all the above.
 
First, any type of delay in an audio signal coming from outside your computer and then being processed by your DAW can contribute to a monitored signal arriving at your speakers out of sync with audio clips already inside of your computer.  External monitoring can help with this.  Sometimes this is referred to as "latency".  Or your audio may be dropping out completely or breaking up with static.
 
But your question seems to be asking specifically about computer performance and the audio system.  So ...
 
Use good ASIO drivers that are supplied with your audio interface.  You want to be able to use the lowest audio buffer size you can get without having audio dropouts.  This is where your audio hardware and drivers must play well with your computer and Windows and your DAW.  If any part of the chain is weak, you could experience problems.
 
The best way to check if your computer is capable of real-time audio is to run this free tool called LatencyMon.  This checks for DPC latency in your Windows system that can cause audio dropouts and glitching.  If your PC fails this test, you will need to fix this first. http://www.resplendence.com/latencymon
 
The best explanation I have ever seen of this PC latency issue is this video:
 
CPU Performance vs. Real-Time Performance in Digital Audio Workstations (DAW)

This is another latency checker, but it only supports Windows up through Windows 7 (some timer changed in Win 8 and the dev is still working on an update).
 
However, the latency troubleshooting info on the site is still very useful and equally applies to Win 8 and 10.
 
http://www.thesycon.de/eng/latency_check.shtml

scook
I caution against conflating DPC latency with audio latency from audio interface drivers and Plugin Delay compensation. DPC lantency has nothing to do with delay one experiences when recording and monitoring a DAW.  Sander in msg#3 provides a good explanation of the causes of the delay experienced when recording and monitoring a DAW.
 
DPC latency is a stability issue. The latency from interface and plug-in buffers is an audio issue.

The original question was, can it be my computer stability or my audio hardware?  Yes to both!!!
 
Everything must work together!