twin turbo question

I searched for it and couldn't find it.

I was doing some reading and it was mentioned that twin (parallel, not sequential) turbocharger setups have less lag than a single turbo setup. other than simplified exhaust piping (fewer pipe bends = better flow = less lag), i really can't see any reason for this, you've got two turbos that are half the size of the single turbo getting half the exhaust and providing half the airflow each, wouldn't that mean they'd take the same amount of time to spool as the larger one?

I remember it having to do with the inertia of the smaller shafts,inpellers,wheels of the 2 smaller turbos. Mostly the smaller diameter vs. the larger outer diameter of one wheel, compressor, et.

I never gave it much consideration and used whichever set-up was easiest to plumb. v-engine gets 2 usually. single exhaust manifold gets one. Many exeptions of course.

That's in line with what I've learned about them. Also, some parallel twin turbos have two different size turbos. The smaller one spools up faster, while the larger one provides more boost after the smaller one drops off.