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PC Specs for Virtual Worlds: General


A good spec PC can make all the difference


In order to appreciate the true majesty of any virtual environment, you require the most apt hardware for displaying sensory data that you can afford. However, this does not mean the most expensive hardware full stop.

For the most part, this article is directed towards home uses of VR. Laboratory and Institute uses have very different setups, and demands on the hardware, plus access to techs that already know what is described herein. The home user with a seven-year-old office computer, who can barely access a modern virtual environment, lagged to death and not understanding why, is a different matter entirely.

Discussing specific hardware is beyond the scope of this article. As the pace of hardware is both changing swiftly, and its pace of change accelerating, such would be pointless; dating this article swiftly. Instead, that task shall be left to daughter articles. Here, we are concerned with what to look for, and aim towards, in order to build a VE friendly PC, regardless of specific hardware.

A note on store-bought computers

Store-bought brand name computers are one off the biggest don't dos if you are looking for performance. If you plan on frequenting a virtual environment, performance is one thing you need.

Yes, they sound good, and if you are planning on the odd email, maybe some document writing, odd spreadsheet or two, then one of these is for you. Bearing names like Hewlett Packard, Olivetti, Compaq, these machines offer great, great power at low, low prices - usually even throw in a free printer and free monitor too. How can they do this?

Simple answer, the machines are crap.

They're office computers; designed for nothing more demanding than document files, spreadsheets, maybe the odd PowerPoint. Yes, they have flashy processors, large hard drives, lots of memory. What you soon notice however, is that aside from these things, none of the other specs inside the machine are given a mention. This seems strange, as there are so many parts to a computer system other than those three.

Whilst the blurb is busy telling you how big the display screen size is, it is frantically not telling you that all the main parts inside have been either stripped out, or reduced to their cheapest alternatives.

In short, even the most modern of these machines is utterly useless for anything that demands a lot of power and continuous performance. They're useless for VR.

That's with a modern machine. These things don't age well. They are designed for offices, and most offices have a rolling replace cycle of 3-5 years. That means if it's 4-6 years old, its too old to even be useful in an office. You can either buy another low-end machine, or build one right, that will last you.

Where to Purchase

The first rule of purchasing a PC, is do not go to the big, chain stores. They make their money by selling vast numbers of overpriced office machines to big business, and passing the same things on to you - why change the spec just because the market changes?

That 399.99 PC looks great, until you gain a little knowledge, and realise you could put the same thing together yourself, same crappy spec, for 200.00 The rest, is just mark-up plain and simple.

Instead, target the smaller stores, the one-man-bands, the PC repair places nestled in between a piano wire shop and a grocery outlet. These are where you find those people willing to put their heart and soul into creating you a PC, their livelihood hinges on people like you, and what you think of their work.

As always, there are cowboys here too. Carry out some research on a place before you buy there. Drive by a few times, park and look in. Do they seem to be doing a brisk business? Is there ever anybody in the shop. The place may be cluttered. Is it clean?

Don't let the technology fool you. Just because a system may be state of the art, is no excuse for a six-inch layer of dirt and cobwebs in the corner. Shop elsewhere.

Does the clerk continually spout nonsense words in long strings, baffling you? Do they go out of their way to explain what they are talking about so that you can understand it? If they don't, and just keep spouting more technobabble, they are trying to cover their own lack of knowledge. A more practised ear can tell the nonsense really is just nonsense, important sounding words strung together to sound important.

You hear this and feel intimidated (unless you know anything about computers)
"I can build you a powerhouse with Intel Opulent 4ghz, 50.5Gb HDD with twin surround sound and 6gb 800mhz SIMMs"

It might as well be this, for all the sense it's making:
"I'm a chocolate teapot, see how I soar. Budda-budda-budda, meooow, woof woof woof"

The only difference is, people are willing to buy from someone saying the former, in order not to make themselves look stupid. Whereas with the latter, they are across the room, slowly edging towards the door.

Do not be afraid to look stupid. That is key. If you do not understand something, ask. If they have not got a satisfactory explanation that you can understand, shop elsewhere.

Building a Virtual World-capable PC

The main board or motherboard

The main board, sometimes called the motherboard, is the centre of the PC. Ignore all claims that the processor is the core, its not. It is important yes, but the main board deals with all the communication between different parts of the PC. The whole thing can only go as fast as the main board will allow.

To use an analogy, the Processor is akin to a river, the main board to an irrigation system.

It does not matter whether the river is slowing past smoothly, filling the irrigation pipes as it does so, or thundering past with an enraged roar. If the pipes are full with the normal river, they are not going to be able to transport any more, no matter how powerful the river gets.

It makes sense then, to not go for the fastest, most powerful processor, but, instead, to go for something still fast, but use the savings from not buying the whizz-bang model, to put bigger pipes on the irrigation system - to get a main board that is capable of communication information more swiftly. The result is far more speed and capability than a faster processor alone could ever net you.

There are three little letters to memorise here. FSB. They stand for Front Side Bus, and are one of the keys to a good main board. The FSB is the data transfer method that carries information between the Processor and the main board. The faster the FSB is, the better, basically.

Occasionally you find two boards that are otherwise identical in FSB speed, but one has a BSB speed as well. If this occurs, take the one with the BSB. A BSB, or Back Side Bus, is a separate data transfer from the Processor to the main memory and back. This means that even if the main roads are jammed with traffic, the PC will always be able to access its memory and recall things on quiet lanes with no other traffic.

In short, it will run both faster and cooler.

As a final addendum to the main board, if there is a toss up between two specs, one with express, and one not, i.e. PCI versus PCI express, always go with the express. Its not guaranteed to be faster, but what it basically means is that the express version connects more directly to the FSB - less side roads flow into it before the express joins in, and so less traffic.

Less traffic equals more speed.

Memory

Contrary to the signs on large store PCs, memory comes in two distinct types.

You have main board memory - cards that plug directly into the main board, and are accessed solely by the FSB (or BSB if there is one).

With main memory, its not just a case of more is better. As you are probably starting to realise by now, data transfer speeds are key. Its not just how much you can store, its how quickly you can find it when you need to. Having extra space will not slow the search down, as each memory module searches independently of the others. However, like the main board, each memory module has its own irrigation network internal to itself. Whilst it will find the information you seek, swiftly, that will do no good if the conduits leading out of the memory are clogged with traffic.

Thankfully, memory comes in different speeds. These like the processor, are labelled in MHz, and GHz. 300Mhz, 800mhz, 1.2ghz, etc. The faster the speed, the more traffic it can fit through at once. However, and this is a big one: It is pointless buying memory that has a faster speed than the FSB is capable of. Using an analogy again, its like trying to fit all the traffic from a six-lane road coming out of heavily urbanised main memory, into a two-lane road on the FSB. It ain't going to work, and you are going to have traffic jams for miles.

So, make sure to purchase the memory that is as close as possible to the speed the FSB runs at - another reason why its important to get the FSB as high as possible.

Do not be afraid to go overboard on the amount of memory. Fill the board with as much as you can reasonably afford. During busy periods, its much faster to shove information into an empty module as swift as you can, and let the memory module's staff sort it out later, than sitting waiting whilst the other modules work out how much space they have free, and where it all is.

Then you have cache memory, which plugs directly next to the processor. Its not on the FSB, and is much faster, purely because its nearer. It cannot hold anywhere near as much, but it is good for frequently used items. Think of it as taking milk out of your fridge every time you'd like a coffee rather than going down to the supermarket every time you feel thirsty. Both can deal with your needs, just one takes significantly longer than the other.

Understanding that, it makes sense that the more cache memory you have, the better, as the more you can store locally. You will never be able to store as much as the supermarket, nor would you ever desire to. However, it does make things that little bit easier. (It's worth noting that cache memory is one of those little things the brand name PCs tend to take out.)

Permanent Storage

Permanent storage, as in long-term storage is a different thing again to memory. Its not used all the time, just when something needs to be kept for an extended period of time - i.e. saved. It is used a lot however, if your computer runs out of memory - any port in a storm will do.

Permanent storage is essentially the hard drive or HDD. It is much slower to access than memory, so if the memory is full, or the transport network to it is snarled with traffic your PC will start using the hard drive as memory. When this happens, performance falls through the floor - you lag to death.

This can be mostly alleviated as stated previously, by as much memory of the speed closest to your FSB speed as possible. Hard drives do not even begin to approach FSB speeds, but what you can do to ease the wait times, is to buy as fast a model as you can. If you are given the choice between a large hard drive at a very fast speed, and a huge hard drive at a slower speed, take the faster one. The ability to send more data at once, so it is in use for far shorter periods, greatly outweighs the extra space on it - you can always buy another later on, if you need to.

Graphics Capability

Now we come to the other, vitally important component that like cache is rarely if ever mentioned on large store blurb about a computer's capabilities.

The ability to render large, complex virtual environments, changing 60-70 times a second so it feels natural, rests solely on the computer's graphics accelerator card or cards. This bears the brunt of the burden in any virtual environment as it struggles to feed data to your eyes as fast as you can take it in.

Remember those bargain PCs at the start of the article? Yep, you guessed it; they do not have graphic accelerator cards at all. They have what is called 'on-board graphics', which means instead of a complex card with several moving parts and a legion of microchips; you have a single, solitary microchip on the main board, labelled 'graphics'.

It will work, and it will get you there. However, it will take its sweet time doing so. A good simile would be to compare a good graphics accelerator with a 747. And, on-board graphics compare with a bicycle. Both will transport you to the same strange and exotic locations. The 747 does so swiftly, and in comfort. The bicycle does so slowly, with a lot of hard work, and you find your holiday is over by the time you get there.

Ideally you should be looking for a card one or two models away from the top of the range. Expect it to be half the cost of the total computer - it is well worth it. The reason not to go for the top models is they depreciate in price swiftly as newer come out. Within two years of a new card coming out with better capabilities than any other, it has sunk to half its price as new and even better models replace it.

The graphics card in your computer will be the first piece to become obsolete, but when that happens, rather than replacing the whole PC, have the card taken out, buy a new, swifter one, and plug it in.

Icuiti Head Mounted Display Glasses
A VR display system needs good hardware behind it,
whether you are using a monitor, VR glasses (above) or both

Sound Card

As with graphics, on a cheap computer, sound is 'on board'. On a PC designed for use in a virtual environment, it's a separate and complex card, with many microchips across its surface and its own separate memory. Sound cards are becoming much of a muchness now, and almost any model will do, but make sure it is card based for crisp, real sound, as opposed to on-board which just cannot cope with the full orchestra at once.

Internet Connection

The internet connection from your PC, to the rest of the world is one of the last truly vital components. From what we have discussed above, hopefully you should now be able to guess why sometimes, when you stick a high-speed connection on an old PC, it does not really perform as intended. Often a high-speed line swamps the communication lines of the computer, burying it in traffic. Not so with a high-speed communication system like the one you now have. As fast a connection as you can acquire will work, and be used well.

Additional peripherals

Lastly, there are all sorts of additional peripherals. Monitor, speakers, printer, keyboard, mouse, microphone, camera, haptic equipment that you may or may not have. Your choices in this area are really up to you.

However, please use common sense. With a monitor, larger screen area is better, and you may like to think about a second monitor, in the form of a VR display unit, worn like glasses. These put you literally into the middle of the VE, with it all around you, no matter where your eyes look.

With speakers, don't opt for a cheap pair, but digital speakers with surround sound and a subwoofer - same as for the TV, you are going to desire to be immersed in the sounds of the environment, not squeaked at from something that grates on your nerves.

…And that would be it. Remember these pointers, and you will find yourself with a system more than capable of handling anything the virtual throws at it, giving you a deeply rewarding and satisfying experience.

Staff Comments

 


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