Archive for November, 2008

AMD announces 45nm Opteron (Shanghai) availability

Thursday, November 13th, 2008

AMD today announced general availability of the next generation 45nm AMD Opteron Quad core processors. The official press release is available here.

Major improvements in the new Opteron architecture (code named Shanghai) in this release are as follows:

  • 45nm Manufacturing Process
  • Larger Cache
  • Support for DDR2 800 MHz
  • Upcoming enhancements for HyperTransport 3.0 (HT3)
  • Other micro-architecture enhancements like
    • AMD SmartFetch
    • AMD CoolCore
  • Maintains platform compatibility leading to better return on investment.

What benefits can you expect from the new processor?

Energy Efficiency without sacrificing Performance: The new generation of AMD Opteron processors utilize the latest AMD 45nm manufacturing process. This process allows greater clock speeds leading to higher core frequencies without dissipating too much heat. As per AMD’s announcement, new generation processors deliver 35% more performance while drawing up to 35% less power. The new manufacturing process also allows much higher clock speeds than the previous generation quad core processors. Over all, AMD Opteron processors combined with support for DDR2 memory offers platform level energy efficiency and 100% x86 compatibility.

Improved Application Performance: The latest generation processors feature two major enhancements affecting application performance: DDR2 800 MHz support and larger cache. The latest AMD Opteron (Shanghai) improves on the previous generation of AMD Opteron processors (Barcelona) with the support of 800 MHz DDR2 memory. This memory technology offers improved memory bandwidth over the previous generation of processors and offer much better energy efficiency than Fully Buffered DIMM (FB-DIMM) technology. A 200% increase in L3 cache to 6 MB benefits a number of applications across verticals, like databases, virtualiztion, JAVA applications, scientific applications, media applications and more. A faster memory bus combined with a larger cache with out complicated prefetching and snooping algorithms offers overall application efficiency.

HyperTransport 3.0 (HT3) Support: AMD Opteron processors provide unparalleled scalability and aggregate memory bandwidith by employing AMD DirectConnect architecture with HyperTransport. Previous generations offered a 1GHz HyperTransport link among the processors. Next generation enhancements planned for Q2 2009 include support for coherent HyperTransport 3.0 offering up to 17.6 GB/s of bandwidth for inter-processor communication. cHT3 will enahce platform scalability for systems featuring 4 or more AMD Opteron processors and will enahce application performance for DP platforms.

Micro-architecture Enhancements: The next generation 45nm AMD Opteron processor (Shanghai) also features enhancement to numerous other micro-architectural features. Some are listed below:

AMD SmartFetch: This technology allows cores to enter in to a “halt” state when the processor core becomes idle. In a ‘halt” state, the processor does not consume power and enhances power efficiency. This technology does not affect application performance in any way thus offering better power efficiency with no penalties on performance.

AMD CoolCore: This technology allows powering down selected sections of the processors. When a particular section is not being used, that section will be powered down in order to enhance power efficiency.This technology does not affect application performance in any way thus offering better power efficiency with no penalties on performance.

Enhanced Virtualization Performance: The next generation 45nm AMD Opteron processor (code named Shanghai) offers unsurpassed enhancements in virtualization performance. Combined with the architectural enhancements like 45nm manufacturing, larger cache, higher frequencies, higher memory bandwidth, cHT3 support, the new processor delivers faster “world switch” time enhancing virtual machine efficiency. AMD’s innovating AMD-V featuring Rapid Virtualization Indexing reduces overhead associated with software virtualization. L3 cache index disable proivdes improved data integrity as well.

With 45 nm AMD Opteron quad core processor (Shanghai), AMD continues to build on its platform strengths while addressing certain drawbacks in Barcelona processors. AMD Opteron (Shanghai) can be used on all systems, with a BIOS upgrade, supporting the Barcelona processors. Customers can avail themselves of the new processors with a simple in socket upgrade without the associated costs of a total hardware replacement. Application software will instantly experience the performance enhancements that come with 45nm AMD Opteron Shanghai processors.

HPC Systems, Inc. a platinum partner of AMD now supports 45nm AMD Opteron Shanghai processors across the product line. Systems featuring the latest generation of AMD Opteron processors are immediately available.

Read the press release here.

Formatting large volumes with ext3

Friday, November 7th, 2008

In RedHat 5.1, the maximum file system size is increased to 16 TB from 8TB. However, getting mkfs to format a volume larger than 2 TB is not straight forward.

We do  ship large volumes to customers regularly. We recommend that customers use XFS for large volumes for performance and size considerations. However, sometimes customers want only ext3 because of the familiarity with the file system.

Before being able to format a volume,  you must be able to create a volume greater than 2 TB. fdisk cannot do this.

You will need to use GNU Parted (parted) to create partitions larger than 2 TB. Details on how to use parted can be found here and here

A simple example of using parted, we assume are working on /dev/sdb of size 10 TB from a RAID controller.

$> parted /dev/sdb

GNU Parted 1.8.9
Using /dev/sdd
Welcome to GNU Parted! Type 'help' to view a list of commands.

(parted) mkpart primary ext3 10737418240
(parted) print
(parted) quit

A straight forward mkfs command on any volume larger than 2 TB will yield the following error:

mkfs.ext3: Filesystem too large.  No more than 2**31-1 blocks
(8TB using a blocksize of 4k) are currently supported.

A simple workaround is to force mkfs to format the device in spite of the size:

mkfs.ext3 -F -b 4096 /dev/<block device>

mkfs.ext3 -F -b 4096 /dev/<path to logical volume> if you are using LVM

In order to use the above command you need to have e2fsprogs 1.39 or above. The above command also sets block size to 4kb.

You could also use -m0  to set the reserved blocks to zero.

Note that ext3 is not recommended for large volumes. XFS is better suited for that purpose.

Further reading:

RedHat Knowledgebase  Article