Does multitasking with computer affect printing?

any heavy streaming downloads, gaming etc is strongly advised against as it steals CPU needed for both slicing (since its done in background in like "Python etc) and printing causing pauses that can last long enough to timeout process and loose the print b4 finished (bummer on long prints) also cause hotend to ruin model etc. non-internet normal computing duties like reading/posting etc have near no effect but results can vary depending on your computers system capacity. I use 32bit winXP on a duo core 2.1ghz processor with 3gb ram, med high grade video board, 1tb HDD etc. have an extra with win7 64bit 2.8ghz duo core with HD video card in case main one crashes. so I dont think lower quality system could handle all the juggling of browsing etc while using RH/slicer. I dont play elaborate online games at all even if printing many hours as my print jobs are much higher priority than killing some virtual army... lol duel extruders etc even more so. an 5 hr print has to deal with well over a quarter million command lines of just gcode. that cant miss a single character or possibly fail. have you ever experienced an error while browsing that requires restart to continue? think what that would mean if 3 hrs into a 4 hr print or worse plus worrying if hotend will melt down while restarting due to no way to shut off heat or run cooling fans? yep been there done that. wouldnt wish it on my enemy.

buy another puter and play on it. the one for printer is now your work puter.

I'm running Sketchup, talking on here, and printing on one laptop right now.

yeah thats not too hard on CPU usage like video games and anything streaming off internet. also depends if your net connection can handle things without loading up virtual memory, ram. like say a weak signal wireless connection

For me, it's not running other apps, so much as fooling around with Repetier while it's printing. 

I had Solidworks and Photoshop running, as well as NetFabb and Meshlab, and worked with them while printing some long print job, while also downloading some stuff in the background. 

Not even a single glitch, but then I start messing around with Repetier itself, it glitches and pauses the print.  Things like trying to scroll through the layer range preview, will pause the print momentarily.  Doing a new slice with either Cura or Slic3r will also glitch and pause the print, not while doing the actual slicing, but when saving the GCode output.

So I don't think multi-tasking is the problem as much as Repetier is too busy using all the resources during a print to respond to other commands without affecting the print.

I'm pretty sure it's not a CPU/Core load issue. It seems to be and I/O issue.

Repetier seems to read the GCode data in real time.  If it buffers any of this data somewhere, the buffer must be very small, it doesn't even appear to hold the contents of one layer.   When you try to write a large GCode file, or when you try to scroll through a 3D preview, Repetier has to pause reading the GCode it's currently printing and do something else, like write a file, or read and search through another file to find the location you asked for.

That is what pauses the prints, not the CPU load.

FYI, I just looked at my task manager, and Repetier is using between 8-10% load on a single core while printing.