This article aims to clarify the question of speed and intensity in the thoughts of Simondon and Deleuze, in order to shed light on the recent debates regarding accelerationism and its politics. Instead of starting with speed, we propose to look into the notion of intensity and how it serves as a new ontological ground in Simondon's and Deleuze's philosophy and politics. Simondon mobilises the concept of intensity to criticise hylomorphism and substantialism; Deleuze, taking up Simondon's conceptual framework, repurposes it for his ontology of difference, elevating intensity to the rank of generic concept of being, thus bypassing notions of negativity and individuals as base, in favour of the productive and universal character of difference. In Deleuze, the correlation between intensity and speed is fraught with ambiguities, with each term threatening to subsume the other; this rampant tension becomes explicitly antagonistic when taken up by the diverse strands of contemporary accelerationism, resulting in two extreme cases in the posthuman discourse: either a pure becoming, achieved through destruction, or through abstraction that does away with intensity altogether; or an intensity without movement or speed, that remains a pure jouissance. Both cases appear to stumble over the problem of individuation, if not disindividuation. Hence, we wish to raise the following question: in what way can one think of an accelerationist politics with intensity, or an intensive politics without the fetishisation of speed? We consider this question central to the interrogation of the limits of acceleration and posthuman discourse, thus requiring a new philosophical thought on intensity and speed.