what sound device are you useing ?
even tho' its old it IS an intel i7 if i read you correctly.
is this a one drive system ? if so beware that filling up one drive of a pc can cause probs if the traks are on same drive as the win OS. cos win can interfere sometimes.
there could be a number of reasons for your issues.
heres a couple of ideas too...
1. as long as it works run a latency monitor piece of software eg latencymon..do you get results in the red ?
2. if its an old hard drive go to a pc tech and see if you can install a ssd. if so youll notice an improvement.
the tech will also optimise the pc n' clean out any junk.
if your interested on pg here and the net are various guides to 'optimise a pc for music production'.
finally if you DO decide on a new pc low latency is important to music production...so just dont buy any old pc. i recommend before buying checking the latency stats of various new pc's on this site.
https://www.notebookcheck.net/DPC-Latency-Ranking-Which-laptops-and-Windows-tablets-offer-the-lowest-latency.504376.0.htmlit would also be usefull if you could post your biab audio driver settings as a pic.
i'll now stop there as an intro to save any confusion.
cept to ask are you useing any other music software other than biab ? does the pc run well on other software ??
i think we all replied inn the same time span...lol.
there are lots of good techs here but they need more detail.
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om