I want to make a choice for the CPU in a new server configuration, I have seen that current Intel Xeon CPUs have various L2 cache sizes 4,8 and 12MB. Do database application like ASA 9 use and take advantage of the extra L2 cache size in a 32-bit Windows Server configuration?
Thank you in advance
asked 31 Aug '11, 03:48
The L2 CPU cache is not managed by SQL Anywhere; it is managed by the operating system. The amount that the L2 cache that will be used is defined by the registry key 'SecondLevelDataCache', available on some Windows platforms. See your operating system documentation for more info about controlling the L2 cache size.
As with all performance tuning recommendations, "it depends" on your workload type whether the extra L2 cache makes a difference. For instance, the related CPU time on a query may not be relevant if your query is really I/O-bound and most of the execution time is spent working against the disk. In that particular use-case, "all CPUs wait at the same speed", so the L2 cache usage on the CPU isn't really going to be a factor.
As John mentions here, some server threads do try to maintain processor affinity to try to eliminate the need for moving large amounts of information around in the processor caches.