oracle (single instance) performance on DL380p Gen8

[joseph pareti]

I need performance figures comparing 2 DL380p Gen 8 models:

1. 1st option: DL380p Gen 8 with ONE quad core cpu: E5-2643 3.3 GHZ
2. 2nd option: DL380p Gen 8 with TWO double core cpu's: E5-2637 GHZ

The memory and I/O susbsystem should be identical or similar in both cases.

In the absence of Gen 8 performance data, it would also help to understand the general trend on how Oracle responds for the same number of cores, but when cores are in one cpu as for case (1) above, or in 2 cpu's as in case (2)

[Matti_Kurkela]

Both CPU models are Sandy Bridge-EP based, so the basic technology is the same.

The quad-core model has slightly higher clock frequency (3.3 GHz vs 3.0 GHz).

In the quad-core model, all the cores share a single 10 MB L3 cache, while dual-core option would obviously have two separate 5 MB L3 caches. So whenever a process would have to migrate from one CPU to another, the dual-core option would have something of a disadvantage compared to the quad-core option: in dual-core option, the other CPU would have to refresh the appropriate parts of its L3 cache, while in quad-core option, any core can simply keep using the data that is already in the shared L3 cache.

On the other hand, having two CPU sockets active means having some more PCIe lanes, which may help if your workload is I/O-heavy and you need all the PCIe lanes you can get. (The first CPU socket needs to use some pins for a DMI 2.0 interface to the chipset hub, while the second and further sockets are free to use them as generic PCIe lanes.) 

So, I would expect the difference to be fairly small. The effect could be either way, depending on the characteristics of your workload: if you make complex database queries that require a lot of process but only a limited amount of I/O, the 1x quad-core might be slightly better, but if you fill all the PCIe slots with I/O cards and make simple queries which access a lot of data, 2x dual-core may be slightly better.

[mhunter]

I know this isn't exactly what you were looking for, but it will shed some light on the performance of a G6, with a lesser setup.

http://www.oracle.com/us/solutions/benchmark/apps-benchmark/ora-lrg-hp-dl380-g6-167250.pdf

http://h20195.www2.hp.com/v2/GetPDF.aspx/4AA4-4606ENW   This discusses DL380p Gen8 benchmarks

http://h18004.www1.hp.com/products/servers/benchmarks/products.html (Benchmark information for the Proliant portfolio)