Intel has finally released the long awaited (at least by me) 45nm Xeon 7500 series processor. This beast has eight cores, plus hyper-threading and turbo boost, and 24MB of shared L3 cache. It also supports up to 16 DDR3 memory slots per CPU socket. This would give you 64 logical cores and up to 1TB of RAM in a four socket server. A system like this would cost roughly $100K. Here is an example of a PowerEdge R910 from Dell.
A more cost effective alternative for many circumstances would be a two socket system with the new 32nm Xeon 5600 series processor. The Xeon 5600 series has six cores, plus hyper-threading and turbo boost, and 12MB of shared L3 cache. A two socket system with the Xeon 5600 would have 24 logical cores and up to 288GB of RAM, and would cost roughly $30K. This system would actually have better performance for some types of OLTP workloads compared to a Xeon 7500 series CPU.
Just today, NEC published a new world record TPC-E benchmark result of 3141.76, for an eight socket NEC Express5800/A1080a-E system with the Xeon X7560 and 1TB of RAM, running on Windows Server 2008 R2 Datacenter Edition and SQL Server 2008 R2 Datacenter Edition. That result is nearly triple the TPC-E benchmark result of 1165.56 for an eight socket Unisys ES7000 Model 7600R Enterprise Server system with the Xeon X7460 from about a year ago, and it is nearly 50% higher than the previous world record (from a 16-socket system).
IBM also published a new TPC-E benchmark result today of 2022.64 for a four socket IBM System x3850 X5 with the Xeon X7560 and 1TB of RAM, running on Windows Server 2008 R2 Enterprise Edition and SQL Server 2008 R2 Enterprise Edition. This IBM four socket system posts a higher TPC-E score than a 16 socket Xeon X7460 system from a few months ago! The top ten TPC-E scores are listed here.