Posts Tagged ‘Performance’

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Short-Take: SQL Performance Notes

September 15, 2010

Here are some Microsoft SQL performance notes from discussions that inevitably crop-up when discussing SQL storage:

  1. Where do I find technical resources for the current version of MS SQL?
  2. I’m new to SQL I/O performance, how can I learn the basics?
  3. The basics talk about SQL 2000, but what about performance considerations due to changes in SQL 2005?
  4. How does using SQL Server 6.x versus SQL Server 7.0 and change storage I/O performance assumptions?
  5. How does TEMPDB affect storage (and memory) requirements and architecture?
  6. How does controller and disk caching affect SQL performance and data integrity?
  7. How can I use NAS for storage of SQL database in a test/lab environment?
  8. What additional considerations are necessary to implement database mirroring in SQL Server?
  9. When do SQL dirty cache pages get flushed to disk?
  10. Where can I find Microsoft’s general reference sheet on SQL I/O requirements for more information?

From performance tuning to performance testing and diagnostics:

  1. I’ve heard that SQLIOStress has been replaced by SQLIOSim: where can I find out about SQLIOSim to evaluate my storage I/O system before application testing?
  2. How do I diagnose and detect “unreported” SQL I/O problems?
  3. How do I diagnose stuck/stalled I/O problems in SQL Server?
  4. What are Bufwait and Writelog Timeout messages in SQL Server indicating?
  5. Can I control SQL Server checkpoint behavior to avoid additional I/O during certain operations?
  6. Where can I get the SQLIO benchmark tool to assess the potential of my current configuration?

That should provide a good half-day’s reading for any storage/db admin…

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ExtremeTech: Shanghai to Istanbul

June 22, 2009

ExtremeTech runs some tests on the AMD Istanbul 6-core processor and compares the 2435 (2.6GHz) part to the 2384 (2.7GHz) part in a drop-in replacement using PassMark and Spec_JBB2005. Testing was performed in the same Supermicro system running an updated (AGESA 3.5.0.0) BIOS supporting Istanbul processors.

“Perhaps, the most tell tale result comes from the BOPS rating scored using SpecJBB2005, which simulates a server’s ability to process JAVA code. Here, there was a 20% increase in performance, with BOPS increasing from 380721 to 471440. That 20% performance boost would [definitely] be noticed on a busy server in a data center.”

Loyd Case, ExtremeTech.com

While not as thorough as Scott Wassman’s drop-in testing at TechReport (reported earlier this month), ExtremeTech’s results and conclusions were about the same: Istanbul makes a great upgrade processor.

“It all comes down to simple math, where one has to consider the cost of the CPUs and the time needed to perform an upgrade to see if the return on investment is worthwhile. Most will find that in this case, it is…”

– Lloyd Case, ExtremeTech

“And if you have existing, compatible Socket F servers, the Istanbul Opterons should be an excellent drop-in upgrade. They’re a no-brainer, really, when one considers energy costs and per-socket/per-server software licensing fees.”

Scott Wassman, TechReport

Both ExtremeTech and TechReport make compelling upgrade arguments in their testing. Compared to a new system architecture like Nehalem, it is logistically less disruptive – technologically and economically – to certify a CPU upgrade versus as platform replacement. After internal certification, a BIOS and CPU upgrade takes about 20-minutes per system to implement. In a virtualized datacenter where low-level differences are abstracted-away by the hypervisor certification testing should be much less invasive. Likewise, rolling upgrades in a virtualized datacenter with vMotion technology can provide a non-disruptive path from 4-core to 6-core. As Case puts it:

“Simply put, by just upgrading five servers in a data center, data center managers can eliminate the need to purchase an additional server to meet performance needs.”

Lloyd Case, ExtremeTech

However, this “upgrade proposition” is a difficult position for AMD as it does little to sell new systems. Historically, CPU upgrades only happen in 10-15% of the installed base, making CPU sales based on BIOS/drop-in upgrades an interesting footnote. Integrators want to move new hardware with Instanbul pre-installed, not sell “upgrade packages.” Perhaps the dynamics of the new economy will drive a statistical anomoly based on the strength of the Istanbul proposition. Datacenter managers face a familiar dilemma with some new twists.


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First 48-core VMmark Appears

June 18, 2009

Following in the footsteps of the first 12-core VMmark comes the current champion at 33.85@24 tiles using 48-cores – and, despite the timing, it is not an Istanbul server. In fact, today’s leader is the IBM System x3950 M2 running 8, 6-core Intel Xeon MP “Dunnington” X7460 processors with 256GB DDR2/667 RAM (5.3GB/core).

This score edges-out the previous champion – the HP ProLiant DL785 G5 with 8, 4-core Opteron 8393SE processors – which reigned at 31.56@21 tiles. In contrast to the 4-socket, 24-core IBM System x3850 M2 Xeon leading the 24-core category, this doubling of socket/core count resulted in only a 50% increase in capacity. This scaling inefficiency is less typical in 2P-to-4P transition but seems to plague the 4p-to-8P segment.

“The x3950 M2 is based on the fourth generation of IBM Enterprise X-Architecture®, and is designed to deliver innovation with enhanced reliability and availability features that enable optimal performance for databases, enterprise applications and virtualized environments.”

IBM News Blurb

“I’m really looking forward to even more virtualization benchmarks which are coming very soon.”

– Elisabeth Stahl, IBM Benchmarking and Systems Performance Blog

Looking at the virtualization notes we discover what it takes to keep 48-cores fed to achieve such a benchmark:

  • 4-QLogic QLE2462 HBA’s (Dual-port, 4-Gbps FC)
  • 1-IBM DS4800 with 4GB cache
    • 19 EXP 810 storage expansion units for
    • 1.8TB in 49 LUNs
      • 280 15K disks total
  • 21 IBM x336 clients
    • DP 3.2GHz Xeon
    • 3GB RAM
    • Server 2003 R2
  • 2 IBM x335 clients
    • DP Xeon 3.06GHz
    • 2.5GB RAM
    • Server 2003 R2
  • Eight vSwitches
    • 120 ports total
  • 4 Intel PRO 1000PT Dual-port 1Gb Ethernet controllers
    • one per vSwitch

While the Dunnington tops the list by sheer brute force, it’s safe to assume that – given the 32-core Opteron is nipping at its heels – the 48-core Istanbul results will displace it soon (possibly alluded to in Elisabeth Stahl’s “Benchmarking and Performance Blog” reference above). More interestingly, will AMD’s much touted “HT Assist” allow the 8P Istanbul to break the 4P-to-8P “curse” of scaling inefficiency? If not, it would show that much work is needed before the relatively “massive ” core counts of 2010 are upon us.