Starting out with the basics, the Radeon HD 2400 XT is based around AMD's 180 million transistor, 65 nanometre manufactured RV610 core, and is basically a further shrunk and reduced version of the R600 and RV630 cores that power the company's flagship Radeon HD 2900 XT and mid-range Radeon HD 2600 XT parts respectively. Compared to the 320 shader processors which make up that current high-end part, RV610 features 40 shader processing units, split into two arrays of twenty processors (compared to four arrays of eighty in R600, and three arrays of forty in RV630). The number of texture units and ROPs are also reduced to one of each respectively against four and four in AMD's flagship core, and two and one in RV630. Finally, RV610 finds itself shorn of the ring bus memory controller found on other Radeon HD 2000 series parts, instead utilising a lesser 64-bit crossbar controller.