Since Larrabee was slated for late 2009 by then, and still is, these numbers felt anything but firm. In any case, they said that Larrabee would operate at 1.7-2.5GHz, sport 16-24 in-order cores capable of up to 960GFLOPS double precision. Radeon HD 4870X2 can do 600GFLOPS in double precision, 2400GLOPS in single precision. According to information posted by Heise, Larrabee with 32 cores operating at 2.0GHz should be capable of reaching 2TFLOPS, unfortunately it doesn't say single or double precision.

It goes on to reveal that the cores are in fact based on the more than 13 year old P54C architecture, known as the original Pentium among the mortals. Even though it's based on the P54C architecture it doesn't necessarily mean that you will find many things in common with the Pentium processor and the upcoming graphics processing unit. The P54C has been shrunk to 45nm, been extended and updated to, for example, feature more cache and updated instructions. Larrabee will also feature 64-bit operations, which makes us believe that the mentioned 2TFLOPS might very well be double precision.