For our CRM back-end we are running an 8 Core 2 GHZ Intel Xeon, with ample disk space (via a SAN) and 32GB memory (29GB allocated to SQL Server).
Windows Server 2012 R2, SQL Server 2012 Enterprise (up-to-date on service packs).
The database server keeps running up to 99% CPU utilization, and since we use the one crmapp account for CRM, we cannot tell what is consuming so much CPU. As well, the CPU is running so high, we are unable to run anything against the SQL Server to see what is running. Logs are showing nothing unusual.