The second generation (Paris/Palermo core) was based on the architecture of the Socket 754 Athlon 64. Some differences from Athlon 64 processors include a reduced cache size (either 128 or 256 KiB L2), and the absence of AMD64 support in earlier models. Apart from these differences, the Socket 754 Sempron CPUs share most features with the more powerful Athlon 64, including an integrated (on-die) memory controller, the HyperTransport link, and AMD's NX bit feature.
In 2006, AMD announced the Socket AM2 and Socket S1 line of Sempron processors. These are functionally equivalent to the previous generation, except they have a dual-channel DDR2 SDRAM memory controller which replaces the single-channel DDR SDRAM version. The TDP of the standard version remains at 62 W (watts), while the new Energy Efficient Small Form Factor version has a reduced 35 W TDP. The Socket AM2 version also does not require a minimum voltage of 1.1 volts to operate, whereas all socket 754 Semprons with Cool'n'Quiet did. In 2006, AMD was selling both Socket 754 and Socket AM2 Sempron CPUs concurrently. In the middle of 2007 AMD appears to have dropped the 754 line and is shipping AM2 and S1 Semprons.
When AMD offered to send us their latest Sempron CPU for review, we honestly felt a little ashamed - we had almost entirely forgotten about the budget CPU that launched last June. Had we missed other Sempron reviews since its launch? Were we too tied up in the higher end desktop processors and the dual core migration to pay attention to AMD's brand new budget line? After a moment's panic, we calmed ourselves and realized something that had surprised us a bit - AMD hadn't released a faster Socket-754 Sempron since its launch in June 2004. Not a single new CPU in ten and a half months. We stopped feeling so bad.
So, it was time for an updated comparison, but luckily, the field hadn't changed much - or had it? Remembering back to our original Sempron review, AMD initially introduced two Semprons: a Socket-A and an Socket-754 version. The Socket-A version has topped out at 3000+ (2.0GHz) and it doesn't look like there's any future beyond it for the aging platform. The Socket-754 platform has yet to out-live its welcome and thus, AMD's newest Sempron, the Sempron 3300+, is a Socket-754-only CPU. The Socket-754 Sempron is based on AMD's K8 architecture, but is a 32-bit only CPU (no x64 support here). As a Socket-754 CPU, the Sempron only features a single channel DDR400 memory controller.
