Celeron 400 series processors are based on Core microarchitecture, the same used by Core 2 Duo CPUs having, however, only one processing core (Core 2 Duo processors have two processing cores). Celeron 400 series main technical specs are:

• Based on Conroe-L core, the same one used by Core 2 Duo but with just one processing core
• Manufacturing process: 65 nm
• L1 cache: 64 KB total, 32 KB for instructions and 32 KB for data.
• L2 cache: 512 KB.
• External clock rate: 800 MHz (200 MHz transferring four data per clock cycle)
• Packaging: FC-LGA6
• Socket: Socket 775.
• SSE, SSE2 and SSE3 instructions
• Execute Disable technology
• EM64T technology (a.k.a. 64-bit technology)

Available models of Celeron 400 series are listed on the chart below. TDP stands for Thermal Design Power and indicates the CPU maximum thermal dissipation.