The main difference from what is shown in those slides is that V8 uses a semispace collector. The SpiderMonkey collector just has a single nursery.
Jon Coppeard implemented a semispace collector for SpiderMonkey, but the added complexity made it a net loss in performance. So we scrapped it for now. It means we get a few objects unfairly tenured, but our measurements showed the actual number was pretty low and not worth the overhead.
It's totally workload dependent, and further GGC tuning (there's a lot to go!) may reverse that balance.
Jon Coppeard implemented a semispace collector for SpiderMonkey, but the added complexity made it a net loss in performance. So we scrapped it for now. It means we get a few objects unfairly tenured, but our measurements showed the actual number was pretty low and not worth the overhead.
It's totally workload dependent, and further GGC tuning (there's a lot to go!) may reverse that balance.