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- written by Brian Cook, Dataram Memory Blog Team Member

Nothing in life is error-free, and computers are no exception.  Computer systems are designed to be very reliable, and to give years of trouble-free dependable service.  However, occasionally hiccups can and do happen.  In the world of computer memory, errors can occur.  Fortunately, many errors are harmless and do not repeat.  They are corrected by the memory controller via error detection and correction (ECC) algorithms and technologies.  Furthermore, memory is one of the most reliable components in a computer system—much more reliable than their mechanical hard disk drive storage cousins.

Working in the Technical Support department at a memory company, you encounter pretty much every type of system and memory problem one can imagine.  Sometimes there is an easy solution to an error message (re-seat or swap a DIMM) and sometimes you can troubleshoot a system for hours, only to find out that the problem isn’t memory related at all!

At Dataram, we go to great lengths in our ISO 9001 certified facility to design, manufacture and test reliable compatible memory that delivers great performance.  However, on the rare occasion that you do come across a memory related error, the following information may be useful to you.

Basically you can break down memory issues into two types.  Installation failures can occur right after you install or upgrade the memory, and operational failures, which occur farther down the road, after the system has been running solid for some time.  Let’s take a look some examples of failures, and how to address them:

Problem:  The system will not pass POST (no video or beeps).

Solution checklist:

1. Ensure that you have the correct memory for the system you have installed it in.
2. Check the user manual or contact Dataram Product Support to ensure that the memory is installed in the correct slots.  (Sometimes larger capacity quad-rank DIMMs need to be installed in a certain order.)
3. If you are mixing capacities within a system, make sure you follow the user manual to ensure the DIMMs are installed in the correct slots.
4. If you are sure the DIMMs are configured correctly, reseat (remove and re-install) the memory.
5. Ensure you have the latest version of the system firmware/BIOS/open boot prom rev level.

Problem:  The system passes POST but the BIOS does not count or recognize all of the memory.

Solution checklist:

1. Reseat the memory.
2. Ensure you have the latest version of the system firmware/BIOS/open boot prom rev level.  Older firmware can cause systems to recognize brand new 4GB or larger DIMMs because they were not available when the original firmware was written.
3. If unsuccessful, try solutions 2 and 3 in the next problem.

Problem:  The BIOS counts the memory correctly and passes POST, but a DIMM or bank of DIMMs is deallocated or disabled by the system processor or OS.

Solution checklist:

1. Reseat the memory.  (I am starting to sound like a broken record).
2. Once you boot to the OS, you should see which slot(s) are deconfigured or disabled.  Replace the DIMM(s) with a spare(s) and that should correct the problem.
3. If your OS does not display deconfigured memory, you will need to replace one bank at a time until you find the suspect bank.
   Note:  Banks can also be referred to as quads, channels, or groups of DIMMs.

Problem:  The system has run for an extended period of time, but now has an issue or crashes.

Solution checklist:

1. Check the error logs to see if a DIMM location has been identified with an error.  Error types includes:
• Correctable Error (ECC).  The system is still operational, but the event is logged.

• Correctable Error count has exceeded the threshold set: (types include intermittent, persistent, and sticky).  This DIMM should be replaced as its behavior indicates it is approaching end-of-life.

• Chipkill Error.  This is a multiple bit error that has been corrected.  If repeated, this DIMM should also be replaced.

• Uncorrectable Error.  None of the existing Error Correcting technologies could correct the event.  This DIMM should also be replaced.

2. To keep your system error free and extent its life, ensure it is receiving sufficient air flow and cooling.  The system fans must be functioning properly, and the airflow vents must not be blocked.  If equipped, make sure the system airflow baffle is properly installed. Monitor the various areas and racks of the datacenter to ensure there are no “hot spots”.  Make sure the inside of the system and the airflow vents are clean.  Dust particles and hair strands can lodge in a memory DIMM socket causing failures.

These tips and solutions will fix most of the problems you encounter.  However, if you’re still having trouble, contact our Product Support team at support@dataram.com or give us a call at 1-800-599-0071, or 609-897-7014 for our international friends.

-written by Michael Stys, Dataram Memory Blog Team Member

In today’s business environment, it is becoming more of a common place to find IT Managers being asked to support more with fewer resources. While at the same time, these IT professionals are operating with a flat or shrinking IT budget.  This is one of the reasons why IT departments are deploying creative solutions that will lower overall long-term operational costs and provide innovative, scalable solutions to address the changing landscape of how their users obtain information.

One of these innovative concepts is cloud computing.  By centralizing infrastructure and applications, IT administrators are now able to more effectively support their clients and deliver content to an increasing number and types of devices. It is like corporations have created a new modern day mainframe consumed with information, and the smart phones and tablet PCs are the terminals we use to access this wealth of information. I guess we are building a smarter planet!

One of the main driving requirements at the center of cloud computing is processing power. For servers to run effectively and provide this increasing demand for processing power, servers require a minimum configuration of RAM. As applications are added to these servers more RAM is then required to maintain operational efficiency. This is why an increasing amount of datacenters are moving towards virtualization to increase the amount of VMs (virtual machines) that can run applications on a single hardware server. The short version is virtualization enables IT administrators to properly allocate the amount of hardware resources required by a specific application. Evidence of this relationship between the power of increased memory and virtualization can be found with VMware’s recent licensing update for vSphere VMware vSphere 5 Licensing Update .

Thankfully, RAM on a $ per GB basis continues to drop. For example, many servers that were purchased only a couple of years ago were sold with 4GB DIMMs. At that time the cost of 8GB DIMMs was too high and typically resulted in the cost of the server doubling. So, the IT department purchased two servers with 4GB DIMMs instead of one server with 8GB DIMMs. Today the price of an 8GB DIMM is at a price comparable or lower than the 4GB DIMM was a few years ago. Or, if you are really looking to maximize your server memory, most of the newer servers will now support16GB or 32GB DIMM options.

I believe in getting the most use out of any asset that I already have and then purchase new assets that will enable scalable growth into the future. If you have a server that is a year or two old, give it new life by maxing out its memory or replacing lower capacity RAM for higher capacity RAM. Then when you want to purchase your next server, look to Dataram to provide you with lower cost, higher capacity RAM.

-written by Colin Pittham, Dataram Memory Blog Team Member

Recent reports have indicated that datacenter power consumption in the US has almost doubled in the last five years and is set to continue at a similar rate in the years to come. With roughly 2W required to cool every watt of power consumed and with energy cost also increasing, companies are facing potentially huge increases in the costs of running their datacenters.

Clearly it is important to understand the overall energy efficiency of the datacenter. Significant savings can be made by adopting greener cooling and lighting solutions. Equally, effective use of new server technologies and careful adoption of high density infrastructures will also help reduce energy costs.

But save for replacing all existing servers with new low energy server solutions, what can be done with the existing infrastructure? Virtualization is a popular strategy—particularly on x86 servers— to improve utilization and make more cost-effective use of the server infrastructure. Unfortunately, virtualization is also a big consumer of memory and memory has fast become the largest power consumer in a typical server. It seems that the drive for efficiency has a significant energy cost implication, too.

Customers are clearly seeking more power-efficient solutions and green memory products are becoming a top shopping list item for upgrades to current infrastructure. Today, at the lower memory density range for x86 based systems, customers can expect to pay between a 10% and 20% premium for lower voltage DIMMS. In contrast, the newer and harder-to-source higher density DIMMs are commanding as much as a 100% premium in price for the lower voltage product. Adoption of these products is understandably slower today, but such is the demand for energy efficient upgrades that customers have indicated that once the premium has dropped to the 50/60% mark, take-up will significantly improve.

This is not surprising as green DDR3 consumes around 40% less power compared to DDR2 solutions. Further, recent studies have shown that moving to green DDR3 can provide savings in excess of 2 Megawatt hours of electrical power per year per server. Green upgrade options are not only cost-effective from an energy perspective, but they also extend the life of your current architecture and are a lot easier and quicker to install than a bunch of new servers.

- written by Phil Muck, Dataram Memory Blog Team Member

Not all DIMMs are created equal.  That is where the JEDEC Memory Module committee JC-45 comes into play.  The JEDEC JC-45 committee is comprised of major DRAM manufacturers such as Samsung, Hynix and Micron and major DIMM manufacturers such as Dataram.  The committee is responsible for the creation of memory module standards, including various DIMM types such as Unbuffered DIMMs, Registered DIMMs, Buffered DIMMs, Low-Profile DIMMs and SODIMMs.

DIMM families such as DDR, DDR2, and DDR3 were all developed and standardized by JEDEC. Future DIMMs such as DDR3 Load Reduced and DDR4 are now in development.

Before a DIMM becomes a JEDEC standard memory module, months of up-front development take place.  All the topics listed below are reviewed and discussed.  If changes are required, adjustments to the design are made and the review process is repeated.  The final design is voted on and approved by the JEDEC members before a DIMM becomes a JEDEC standard.

• DIMM Configuration
• Connector Pin Outs
• DIMM Dimensions
• PCB Traces Topologies
• Clock Stub Lengths
• Impedance Controls
• Power Plane
• PCB Stack-Ups
• Simulation
• System Verification

Non-JEDEC compliant DIMMs may have an initial low up-front cost, but the long term costs of unstable systems errors, system crashes and downtime outweighs that initial saving.  Skipping any of the above steps could have devastating consequences to the data integrity of your workstation, servers and blades.  Incorrect PCB stack-up may cause crosstalk issues. Incorrect impedance may cause signal integrity issues.  Inadequate power plane designs may cause random ECC errors.  A DIMM is more than some DRAMs on a PCB.  A correctly designed DIMM has hundreds of hours of engineering behind it.

Why use JEDEC compliant DIMMs?  DIMMs developed in accordance with JEDEC memory module standards assures 100% compatibility in today’s computer servers, desktop systems, telecommunication and other consumer and business applications.  A DIMM manufacturer that is an active JEDEC member understands the steps required to make a reliable DIMM and they also understand the consequences of taking shortcuts.

-written by David Sheerr, Dataram Memory Blog Team Member

If you’ve ever gotten a static shock after walking across the living
room in your socks on a cool dry winter morning, you know just how
easy it can be to unintentionally build up an electrostatic charge.
Once you’ve built up a static charge, the instant you touch something
conductive, an electrostatic discharge, or ESD occurs.

When you touch a door knob after building up a static charge, the
resulting ESD causes no harm beyond surprising you. When you touch a
computer component after building up a static charge, the results can
be disastrous. An ESD of just 10 volts can damage the silicon-based
chips used in most computer components. Your motherboard, RAM, CPU,
and graphics card are all susceptible to this type of damage, and even
a low voltage ESD can render these components completely useless.

To make matters worse, you could release a 10 volt ESD without knowing
it. It’s entirely possible to build up and release a small charge
without ever noticing it, or feeling the shock associated with larger
ESD’s. That’s why it’s extremely important to ground yourself before
doing any work inside of your computer.

There are a few different methods you can use to ground yourself while
working on a computer. An ESD wrist strap keeps you from releasing an
electrostatic discharge by keeping you connected to a metal object at
all times. The strap consists of a metal clamp attached to a wire that
gets connected to a wristband with a metal plate on the inside of it.
By attaching the metal clamp to a piece of metal such as the inside of
an aluminum computer case you’ll have a constant connection between
your skin and that metal. By putting on the wrist strap before
touching any computer components, you can ensure that any ESD will
occur between you and the metal you’re attached to rather than you and
the inside of your computer.

An ESD resistant wrist strap is the ideal method for preventing an ESD
from ruining your computer, but it’s not the only method. You can also
touch a metal object prior to touching a computer component to ensure
that the component will remain safe. If you choose to use this method,
you’ll have to touch metal each time you want to touch a computer
component. It’s easy to forget to touch metal before touching a
computer component, making this a risky method for preventing ESD.

There’s nothing more exciting than firing up your computer after
making major upgrades to it, and there’s nothing more frustrating than
discovering that the new component is dead. By taking steps to prevent
ESD, you can ensure your new hardware will work properly once
installed.