Titan has 18,688 nodes (4 nodes per blade, 24 blades per cabinet),[REF] each containing a 16-core AMD Opteron 6274 CPU with 32 GB of DDR3 ECC memory and an Nvidia Tesla K20X GPU with 6 GB GDDR5 ECC memory [REF].
Titan runs the Cray Linux Environment, a full version of Linux on the login nodes that users directly access, but a smaller, more efficient version on the compute nodes [REF].