Sunday, October 17, 2010

. . . MPCU: Power Supplies

Modular PC Upgrade Series Part 5
(from the Cape Cod Times Digital Grind Column)

A Brief Foreword on this Series

This post is part of a multi-part series on the subject of Modular PC Ownership.

The system of Modular PC Ownership espoused in this series follows a green conservation approach to technology that is intended to reduce your individual carbon footprint, save you money, improve your computing satisfaction, and increase the value in many respects that you receive from your personal computer. Each posting on this blog has been created to support and enhance a related column published in the newspaper.

Today's posting supports the column: Upgrading? Now's the time to seize power, which is the August 3rd, 2010 Cape Cod Times Digital Grind Column.

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Table of Contents

Part 1: Speaking of MPCU -- Introduction
01: Preface
02: Introduction
03: The Economics of Modular Upgrading
04: Introduction Conclusion

Part 2: Speaking of MPCU - Keyboards
05: Introduction
06: Connectivity Options
07: Keyboards Conclusion

Part 3: Speaking of MPCU - Controllers & Sound
08: Introduction
09: Controllers
10: PC Sound
11: Controllers & Sound Conclusions

Part 4: Speaking of MPCU - Computer Cases
12: Introduction
13: What a Case Should Do
14: How to Begin Building your Foundation

Part 5: Speaking of MPCU - Power Supply Units (PSU's)
15: Introduction
16: Selecting a Power Supply
17: Quality vs. Cost

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Power Supplies

15: Introduction

The history of the Personal Computer can trace its origins to a complex collection of parts that were packaged with an instruction manual requiring more than a passing familiarity with a soldering iron, multi-meter, and firm grasp of Ohm's Law. In fact the establishment of the PC as a legitimate piece of office equipment -- let alone a device for the home -- owes a considerable debt to a common device found on most business desktops: the calculator.

Arguably the first true personal computer -- called the Altair -- was created as a product of desperation by a man named Ed Roberts, who owned an electronics assembly kit business whose principle line was largely electronic calculators. The invention of the Integrated Circuit (IC) fomented a radical change in the manufacture of calculating devices, which up until the mid-1960's consisted largely of the masterful engineering of moving parts. These largely mechanical devices -- whose output was invariably printed on narrow strips of white paper that were clipped to the document being totaled -- were a product of a conservative approach to the process of number manipulation, created for industries that were thought to be resistant to change.

The bulk of Roberts' business consisted of hobbyists who assembled electronic calculator kits, but once the manufacturers of calculators embraced the IC and began to produce product lines that were centered around it, Roberts' found his customer base drying up. In what might be described as a defensive reaction, Roberts looked for other devices that might appeal to the electronic hobbyist and concluded that the personal computer was the answer. Shortly after he created the Altair kit, Roberts found himself unable to keep pace with demand because the public was clearly ready for the personal computer, and his success with the Altair did not go unnoticed.

In just a few short years other manufacturers recognized that untapped market, and Roberts soon found history repeating itself, as his competition used innovation and their established manufacturing base to move the PC beyond a device that consisted of a complex system of switches to the more recognizable keyboard based computer that we use today.

Along the way other devices were integrated into the design of the PC, starting with the video display screen, which in early PC's was built into them rather than connected as a peripheral. Next came the removable disk drive, and eventually the fixed disk (hard drive), sound circuits, and upgradable components like serial ports, parallel ports, and pointing devices. All of these optional add-on devices altered the basic power needs of the PC, which previously were served by a fairly simple built-in power supply that provided a clean source of single-voltage power that the device used.

As the PC grew more complex and capable its power needs also altered, until we find ourselves with the current state of the PC, with an average requirements of three different voltage requirements that all come from the same power supply. Building this as a kit is no longer a practical approach, and not simply because it can be done cheaper and more efficiently by way of mass production, but because the power requirements for the modern PC are exacting, with a list of needs that include clean power in specific voltages that must be consistent.

The power supply for early PC's was, like its case, an integral part of the system design, and was not easily swapped out; when a power supply on the IBM PC went bad the usual course of repair was just that: a technician replaced the part in it that was bad. Modern PC's are built upon a modular approach, and the low cost of their devices promotes a different approach -- when a piece of your computer goes bad or breaks, you replace that piece rather than repairing it, both because it is cheaper to do it that way, and because the skilled repair infrastructure no longer exists in the market.

With that approach to PC components being the standard, it should not be a surprise that the power supply industry began to specialize in the 1990's, producing different models of power supply for different purposes. The general-use PC with its limited needs required what is today considered to be the basic power supply, while the high-performance gaming rigs currently popular have a more specialized set of requirements, which created a highly competitive market for user-installed power supplies and replacement power supplies.

This change in how the device is considered has had the effect of elevating the power supply from a minor factor for a PC build to the level of a core consideration, with most PC builders and owners giving the power supply as much importance as the motherboard or CPU. The end result of this is a market that includes branded power supplies with product lines with so wide a variety of features so that choosing a PSU is now almost as confusing as the process of choosing a CPU! The result for the end-user is similar to what has happened with motherboards, CPU's, and video cards -- the process of selecting the power supply is one more compromise in the build that often comes down to the issue of price rather than features or tech.

16: Selecting a Power Supply Unit (PSU)

At last count, when you consider the different models of PC created as boxed offerings as well as the variations of PSU that are offered for new and original PC builds, there are an estimated 25,000 different types of PSU on the market. If you narrow the selection just to PSU's that are suited for consideration for a new custom PC build, that number still surpasses 4,000 and that does not take into consideration the units that are designed as part of the standard case in a generic build.

A quick check of websites like Newegg, Tiger Direct,, or Fry's -- just to name a few -- turns up around 97 different manufacturers of PSU's, and each maker has an average of 6 product lines, within which are often a dozen different models per product line. With numbers like that it is not just the average consumer or hobbyist who is contemplating a custom PC build who end up confused and struggling to make sense of the market -- professional PC builders also find the choice of PSU to be an often confusing proposition!

The major difference between the professional builder and the average hobbyist however, is simple enough: the professional knows that there is a certain minimum level of features that must be maintained, and invariably makes their PSU choice using that standard combined with an estimate of the future power needs of a system based upon what they know the end-user will do with it, and where they think the future of PC hardware will develop.

  • Replacement PSU's
The process of selecting a replacement PSU for a damaged unit is perhaps the most simple choice when power supplies are the part being replaced, because the choice for general-use PC's is often simply the same model that has gone bad. Replacement for a system that is used for Computer Assisted Design / Computer Assisted Manufacturing (CAN/CAM) is a bit more complex, while replacing a unit in a system that is used for gaming is even more complex. Often the process of replacing a PSU is viewed as an opportunity to expand the capability of the PC in ways that the original equipment manufacturer did not consider when they spec'd out the original design.

The first major consideration in replacing a PSU is whether the user is considering an upgrade of their video card. Only three years ago the vast majority of video cards drew all of their power from the PC bus, which means that plugging the card into the PC expansion slot was all that was necessary in order to power the video card. That is no longer the case -- most modern video cards today require additional power using special cables that are part of the modern power supply -- but having one of those cables as part of the PSU is only one element to consider.

Video card technology is moving in new directions today, with the standard being built-in components on cards that duplicate or replace processing responsibilities that previously fell to the PC itself. Modern cards now feature onboard RAM that is often faster than the system RAM, and often include multiple CPU's that are built into the card to take over processing graphics. These two expanding technologies represent pivotal methods for increasing both the capabilities of a PC and its speed that is independent of the computer!

Manufacturers of graphics cards try to address the needs of the software companies whose products best utilize their cards, with video game studios being the greatest demand source for graphics card technology. An office productivity suit is not going to stress a video card, but a modern video game that uses complex layers of graphical display will, and often to its limits. The result of this has been a movement to combine the inherent capacity and processing abilities of multiple video cards in a single system!

  • Multi-Head vs. Multi-Card
In the past when a user wanted to add additional video displays to a single computer the choice usually involved adding an additional video card. Most modern high-end cards can usually support more than one display -- and on a general-use PC that is often enough -- but when the system is used for gaming or graphically-intense engineering or design programs, hanging more than a single display off of a card can actually degrade performance of the system.

In that case adding a second or third video card is absolutely required, with the configuration in that situation largely dictated by the desired effect. For graphics rendering, design, and using programs like Adobe Photoshop, the configuration is usually independent, meaning that each display is connected to its own graphics card, and given sole control over that cards resources.

High-end gaming and certain types of computer assisted design often require a more flexible use of the graphics resources in the PC, so in those circumstances it is preferable to have all of the cards in a PC linked together, their resources shared, and the utilization of their processing power and RAM shared out among the displays.

Ultimately the installation of multiple high-end video cards means a much higher set of power requirements on a system, which means that this potential draw must be taken into consideration when selecting a replacement power supply! A general-use PC might never require more than 500 watts of power, which means that selecting a 650 watt power supply is more than adequate for the current and future needs of the PC, but at the other end of the spectrum it is often necessary to over-compensate for power needs in order to provide the foundation for future expansion.

After tallying up the current needs for a system and arriving at 800 watts, the builder may be tempted to pick an 850 watt power supply for the build and call it a good day -- but if that build includes three graphics cards the simple act of replacing them at a later date with newer more powerful models could easily push the minimal system needs above 1,000 watts. That means that the 850 watt PSU that seemed more than adequate when it was chosen as a replacement PSU now must be replaced not because it is failing, but because it fails to meet the minimum power needs of the system! In that case a 1,250 watt PSU would have been the correct choice, even if it seemed like overkill at the time.

  • Balancing Price and Capability
The difference between the price of an 850 watt PSU and a 1,250 watt PSU is considerable, and though we do not like to admit it, price is often the higher measure of consideration when we are contemplating replacement, or selecting components for a custom build. The old saw that you get what you pay for applies here -- that $250 savings in selecting the lower wattage PSU at the time may end up being a total wash; the original savings of $250 ends up costing the PC owner way more in the end, because they are out the $300 spent on the original PSU plus the $550 that they now have to spend on a properly powered unit, so the cost of saving $250 at the time of the replacement or build turns out to be a whopping $850 in the end.

When considering a replacement PSU or picking one for a new build, the first step is determining the current power needs for the hardware that has been selected or is already present in the system. The second logical step is to estimate what the worse case scenario could be for future power needs. How many devices are in the system? Take a look back at the development cycle of these devices to see how big the power needs changed between versions going back two or three generations.

If the jump in power needs for a video card of the type that is used in the system averaged 100 watts, use that number to estimate the potential future needs -- but multiply that by three, because you may end up adding two additional cards to your system. Use the same approach for the storage devices, and do not forget to factor in devices that receive power from the bus, in particular USB devices. Once you have that new total, add an additional 20% just to be safe, and you now know what your base power need may be for the future.

The most popular form of custom-built PC today is based upon the Bare Bones Systems that are offered by practically every PC and parts website on the Internet. Many PC manufacturers offering out of the box systems also have lines of Bare Bones Systems that are sold via third-party vendors, because this approach removes most of the headache of spec'ing out a system.

Most generic builds -- what are called Bare Bones Systems -- consist of a medium grade case and power supply rather than a high-end case and modular PSU as a result of the basic economics of the product. Bare Bones Systems are created to permit the average PC owner to select a system using a key set of criteria -- CPU capabilities, motherboard, and basic RAM. It is fair and accurate to view these systems as "kits" to which the user will then add components to complete and customize them.

A Bare Bones offering usually includes a minimum level of RAM, the CPU and motherboard, a case and power supply, often a keyboard and mouse. Usually the graphics capabilities of these systems is represented by whatever card is built into the motherboard, and for general-use builds that is often perfectly adequate. Some offerings include a hard drive, and it is common to find a discounted selection of Windows OS included as an option.

When the user is putting together a more specialized system -- a gaming rig for example -- they will be upgrading and adding components to the purchase. More RAM, hard drives, a better CD/DVD or BluRay drive, and a better graphics card that will replace the onboard graphics. The one thing that they rarely every consider, let alone upgrade, is the PSU.

  • Medium Grade PSU's
Identifying the quality level of a PSU is not a difficult process. The medium grade PSU's that are usually included as part of a Bare Bones build have a distinct appearance.

The unit illustrated here is typical of the medium grade modular PSU that is used in these builds. The dimensions are uniform, and the quality of the cabling and connectors typical of that pictured here. One aspect in particular is that the cluster of cables is hardwired into the unit -- whether you use them all or not, they are present. Devices that require special cables can only be used with these PSU's if a form adapter is available. This type of PSU is the perfect example of how a component is built when the specification is for the cheapest cost possible.

Medium grade PSU's will get the job done, but that describes the entire approach to these PSU's from quality to form factor. They are less than a compromise, but fortunately like their higher grade cousins they are built using a standardized system of attachment, which means that they can be easily replaced.

Pictured here is an example of a high-grade PSU. The differences between this and the previous example are immediately evident upon inspection, with the appearance and the system of cabling being the most obvious. The cables that supply primary power for the motherboard are the only cables that are hardwired to the PSU, while the cables that provide power to the peripherals use a modular plug-in approach that is color-coded and based upon unique plug forms in order to prevent confusion.

Supplied with the PSU is a set of modular cables, allowing the user to install just the cables that are needed, which cuts down upon clutter in the case, and permits proper cabling without the use of adapters, which often represent the weakest point in a power scheme. The dimensions of the PSU are similar to those of the previous lower grade, and while larger capacity PSU's may be slightly deeper than the average sized units, they will still fit easily into most Bare Bones cases.

Upgrading the PSU for a Bare Bones build, or selecting a higher quality PSU as a replacement unit is a sound approach for several reasons. The cheaper grade PSU's often have very limited warranty coverage if any. If any flaws in the PSU are not apparent within the first 90 days of ownership, chances are the maker will not replace the unit after that time period, because 90 days warranty coverage is typical for this grade of PSU. The higher grade units like the Toughpower 750 watt PSU pictured above come with 5 year warranty coverage, and their manufacturing process is structured to include a much higher level of quality control, which means that they are much less likely to develop problems related to manufacturing.

There are other equally obvious benefits to using better grade components, but not having to replace a bad unit is a major plus in my book. The quality of design in the higher-grade models includes better thermal management, which means that these PSU's are often nearly silent, as they do not require a built-in fan set at its highest revolution to provide cooling. In addition to that, and acknowledging that the effect is superficial to the consideration of PSU tech, these units simply look cool!

Part 17: Quality vs Cost

When phrases like "higher-grade" are raised with respect to computer components both for replacement and as part of a custom build, the average user presumes that there is a cost to them. In many areas of technology that principal holds true -- you get what you pay for. There ain't no such thing as a free lunch. Quality costs. While that may be true in most cases, personal computer tech is often an exception to the rule, or more accurately, the cost is often less than you might suppose.

  • A good example of quality and costs
If you visit the website for Tiger Direct ( and select Barebone Computers from the main menu, and you are presented with a selection of the Bare Bones Systems that they offer for sale. Pick a mid-range general-use system with your emphasis being economy that is intended as a Home Entertainment PC -- for our example we will use the B69-1205 Kit -- which is a fairly common design for multimedia home entertainment PC systems.

The base cost of the unit is $189.99 and for that relatively low cost here is what you get:
  • Biostar G41-M7 Motherboard
  • Intel Pentium Dual Core E5300 Processor
  • Kingston 2GB PC5400 DDR2 Memory
  • Power Up Black ATX Mid-Tower Case with 450-Watt Power Supply
That is a pretty good starting point for a general-use build. The CPU is actually a bargain unit considering that it is a generation old, but it is perfect for general-use computing and can even handle most modern games, including MMO's as long as the system has a decent video card installed in it.

The system comes with 2GB of RAM, which is perfectly adequate for a 32-bit version of Windows 7 or Windows XP. To this you would be adding a hard drive, CD/DVD drive, and a good video card, which will add anywhere from $325 to $700 to the cost of the build, but you end up with a very nice system for less than it would cost to purchase an out-of-the-box brand name model with similar capabilities.

Now let's say that the PSU failed after the warranty expired on the purchase. This is a standard 450 watt medium-grade PSU, and to replace it with a similar unit will cost around $49.99 for a generic 450w PSU. Or you could replace it with a high-grade name brand unit like Coolermaster's Elite Series 460w PSU -- for $8 less. That is not a mis-print, the cost of a Coolermaster Elite Series 460w PSU is $41.99, $8 less than the cost of replacing that PSU with a generic 450w PSU!

Now let's say that you want to add some extra watts since you plan to upgrade your system later anyway, and as you have to replace the PSU you may as well install some extra capacity in the process. For a little more than twice the price -- $109.99 -- you can replace it with one of Thermaltake's TR series 800w PSU's, which comes with their standard 5 year warranty and modular cabling system.

There is truth in the saying that you get what you pay for, but it pays to shop around. Often it seems to me that I am proselytizing when it comes to the modular building and upgrade approach to PC ownership -- and perhaps I am -- but the benefits to this approach so outweighs the drawbacks, and it is such a logical means of maintaining computing power that it is worth the effort.

Computers -- and specifically the Personal Computer -- are often part of the relationships that we have in our life. I don't mean to imply that there is a reciprocal relationship present such as that which exists between two sentient beings -- obviously a computer cannot return your affection. But that does not stop people from identifying with their computers! Most owners pick a name for their computer that has subtle but significant meaning to them. Most owners feel a sense of pride in ownership, and care that their PC can meet their computing needs. Like their automobile, most owners have a minimum level of expectation for their PC, and considering that they spend a great deal of time sitting in front of and using it, that makes sense.

I am an observant person -- in fact people watching is one of my hobbies -- and one thing that I have noticed among my friends, relatives, and acquaintances, is that rarely ever do they get rid of their old PC when they replace it with a new one! Invariably it is either placed elsewhere in the home as a second system, or re-purposes to preform another function, as a file server, print server, or entertainment system. With the addition of another hard drive and software many of my friends turn their old system into a digital DVR to record their favorite TV shows and movies and offer basic web surfing capabilities to their living room entertainment center.

Those who do not re-purpose their old computer pass it on to some other family member -- it is fairly common for a parent to give their old PC to a child when they replace it. Why do they do this? I am sure that part of the reason is the value that they feel for the PC, and for its inherent and intrinsic value, but there is also the question of the emotional attachment that they have for the PC. After all, it gave them years of useful service, and was their gateway to the online world.

When you adopt a modular ownership system, instead of replacing your PC you upgrade it, replacing the various parts and thus its capabilities. By doing this you not only save money, but you get the full measure of the value of what you spent on this system, which for most people is a very attractive element in the process.

Replacing the case and the PSU for your system with a more robust and option-rich case and powerful PSU is the first logical step in the process of shifting to modular PC ownership. If you read my column and blog entries on cases, and do a little research of your own online, you are certain to find more than just a few case designs that lock-in to your idea of what a computer should look like, and what its basic capabilities should be.

We are constantly reminded of adopting a green lifestyle, to recycle, and to reduce our carbon footprint -- this modern day era of conservation is not simply an extension of the earlier notion that material responsibility is good for the planet, but is a logical extension of the bad economy and the very real need to save money. Modular PC ownership neatly fits into that scheme and approach on multiple levels, and offers not just the opportunity to save money, but to increase the value of the money that you have already spent on your PC.

So far this series has covered the basic introduction, keyboards, controllers and other input devices, peripherals for enhancing the sound and music in our PC's, the cases, and now the PSU's. There is still a lot to cover in the series both here on the blog, and in the column, and you can expect me to address motherboards, graphics (video cards), media and storage, thermal management, and the many types of peripherals that attach to our computers, as well as the different kit that we can use for networking them together to give us a wired house and shared access to the Internet.

Each piece in this series will include an updated entry in the Table of Contents -- so you can jump to the top of any entry in the series and navigate to the next, or to the one covering the tech you are interested in, even when there are other blog entries that appear in between the series pieces. While I have previously touched upon it, I want to remind you that these blog postings are intended to compliment the columns from the series that appear in the Cape Cod Times -- and remind you that to best use these posts, you should start with the related column in the newspaper -- the online version of which can be easily accessed from the paper's site, or through the link that appears at the beginning of each post on the blog.

As I conclude this section of the series I want to thank you for reading the paper, thank you for reading the series, and thank you for considering Modular PC Ownership as a viable and green solution that lets you save money while improving your overall computing experience!


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CM Boots-Faubert is a freelance writer, author, and columnist. He writes the Digital Grind Column for the Cape Cod Times, and the Game On: Cape Cod Gaming Blog at the paper. He writes extensively on video games and gaming, both as a freelance journalist and as a walkthrough writer, reviewer, and previewer. His books include the soon to be published title Games Journalism 101, that discusses how to establish a career writing on video games, and his title in the Hand's On Series, Hand's On: Home Networking which is a complete guide targeted at the average PC user on how to design and build a home computer Ethernet network.

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