A8N-E supports AMD 939-pin Athlon 64 FX/ Athlon 64 processors with 1MB/512KB L2 cache which is based on 64-bit architecture. It features 2000/1600 MT/s HyperTransport Bus and dual-channel un-buffered DDR400 memory support.
This motherboard supports AMD 939-pin Athlon™ 64 X2 Dual-Core processor with 1MBx2 or 512KBx2 L2 cache which is based on 64-bit architecture. It features better multithreaded / multitasking performance than Athlon™ 64 FX / Athlon™ 64.
4 x 184-pin DIMM Sockets support max. 4GB DDR400/DDR333/DDR266 ECC/ non-ECC un-buffered DDR SDRAM memory Dual Channel Memory Architecture
Hope this helps.