The needle in the haystack test gives a very limited view of the model’s actual long context capabilities. It’s mostly used because early models were terrible at it and it’s easy to test. In fact, most recent models now do pretty good at this one task, but in practice, their ability to do anything complex drops off hugely after 32K tokens.

RULER is a much better test:

https://github.com/hsiehjackson/RULER

> Despite achieving nearly perfect performance on the vanilla needle-in-a-haystack (NIAH) test, all models (except for Gemini-1.5-pro) exhibit large degradation on tasks in RULER as sequence length increases.

> While all models claim context size of 32k tokens or greater (except for Llama3), only half of them can effectively handle sequence length of 32K by exceeding a qualitative threshold, Llama2-7b performance at 4K (85.6%). The performance exceeding the threshold is underlined.