Fixing broken computers and advising people on computer hardware is almost like a hobby for me. Most of my friends tend to ask me for details when they are planning to buy a new computer or want to upgrade components; therefore, I thought I’d share some of my experiences with you and hope someone can benefit from this series of posts.
Lately notebooks have become more popular due to their versatility and increasing processing power. In 3rd Quarter of 2008 notebook shipments to US surpassed desktop systems for the first time in the history, it’s a clear indication of the fact that notebooks are the future of computing. Since more and more people are switching to notebooks I thought this would be a good time to post something like this.
CPU (Central Processing Unit)
As all of you know CPU is the main processing unit (brain) of a computer. Therefore power of the CPU is important (however not always the key component, e.g. for gaming; we will talk about that more later). Processor speed (measured in GHz) is the primary performance indicator; however there are many other aspects to consider when choosing a CPU. Among these, number of cores is a key factor. A core is a single processing unit, which means a dual core CPU in essence has two processors working together, and a quad core has 4. Therefore a dual core 1.5GHz processor is generally quicker than a single core 2GHz processor. Amount of cache memory is another important detail, you can think of the cache as an extremely fast and small RAM; this holds data which is frequently used by the CPU for quick access, hence more cache is better. Finally Front Side Bus (FSB) speed or the speed at which the CPU communicates with other components of the computer (including RAM, graphics adaptor) is another performance indicator. However amount of cache and FSB is less prominent compared to the number of cores and CPU clock speed.
There are two main CPU manufacturing companies: Intel and AMD; there is however an emerging company called VIA who started making notebook CPUs recently, but their market share is too low. There are so many CPU models available by both companies, following table lists some of the more common model numbers for your reference:
RAM is another performance critical component. RAM size (measured in GB), speed (clock speed measured in MHz, which is also the speed it communicates with CPU) and the operation mode (Dual channel : two RAM modules work in parallel to double the data rate [needs two RAM modules], Single channel : Only one module works at a time [usually when there is only one memory module]) are the only three configurable options. However, size is the most important of them all. A typical notebook today has somewhere around 2~4GB of DDR2 (533MHz or 667MHz) RAM in dual channel mode. But the latest ones have DDR2 800MHz and DDR3 RAM, which is something to look for if you need a high performance notebook.
Mobile Platform : Centrino Duo, Centrino 2, Kite, Puma…
You may have wondered what some of the stickers pasted on notebooks i.e Centrino, Centrino Duo etc. means. In reality they are not very important, but I feel I should mention something here because many have asked me this question and there is a general misconception surrounding these logos.
When you consider a computer there are many different components: CPU, RAM, Graphics card, hard disk, network adapters etc.. But have you ever wondered what manages all these components? Well, the simplest answer is a motherboard Chip set. A chipset consists of two chips working together, one chip (north bridge) handles communication between the CPU, RAM and graphics card while the other one (south bridge) takes care of Hard disk, network adapters and other peripherals. A mobile platform generally refers to the chipset and the CPU. AMD doesn’t heavily brand or advertise their platforms but Intel does, they even went one step further to include the wireless adaptor as a part of the platform. Centrino is more of a standard set by Intel than a technology, for a notebook to carry Centrino logo it has to include an Intel CPU with a compatible Intel chipset and an approved Intel wireless adaptor.
Centrino 2 platform is the latest offering by Intel which includes a 3rd generation Core 2 Duo CPU (P8xxx, P9xxx) Intel 45 mobile series chipset and Intel 5000 series wireless adaptor (supporting wireless N and Wi-Max).
GPU (Graphics processing Unit)
GPU is Commonly referred as the video card or graphics adapter. Basic task of a graphics adapter is to process and display either 2D or 3D content on the screen. However modern cards are also capable of rendering 3D models (calculations required to translate a mathematical representation of a 3D object to a photo realistic display object, rotate and transform), applying lighting effects (illumination, reflection, shadows), physics calculations (calculating trajectories, collision detection) and even video decoding (Mpeg 4, H.264).
There are two types of graphics adapters : Integrated and discrete. Discrete graphics adapters have a dedicated Graphics Processing Chip and very high speed dedicated video RAM, on the other hand integrated adapters are integrated in to the north bridge chip of the chipset and use system RAM as video memory. Therefore integrated cards are much slower than discrete cards.
Currently there are 3 major graphics card manufacturers: nVidia, ATI and Intel (only integrated cards). The most recent models include nVidia Geforce 9000M series ATI HD 3000 series and Intel X4500.
Most notebooks use magnetic disk based hard drives, but lately a new breed of disks : namely, flash memory based solid state drives (SSD) have come up. It’s Technology is very similar to a normal USB flash memory. Since there are no moving disks; they are noiseless, shock resistant and fast. Random seek times are much faster than a regular hard disk, but have slightly low write speeds. Flash memories have a limited read/write count, therefore earlier SSDs had a limited life time, but this is becoming a lesser problem with new drives. However, still the cost is prohibitively high for most of us to justify performance increase.
When talking about regular HDDs, speed (aside from the obvious factor : size) is also important. A Hard disk’s speed depends on many factors, mainly how fast the disks rotate (RPM : Revolutions Per Minute), but other characteristics like seek time (how long it takes for the head to position itself above the correct location to read/write), Data transfer rate and amount of on-board cache (a small high speed buffer used to enhance performance by prefetching and write sequencing) also has some importance. But generally hard disk speed is denoted by disk rotation speed. There are two speed ratings for normal notebook hard drives : 5400RPM and 7200RPM. 7200RPM disks are recommended for performance critical computing (gaming and handling la large volume of data), but they are relatively expensive and produce slightly more heat.
There are mainly two types of notebook screens: the more popular standard LCDs and new LED backlit LCDs. Regular LCD screens use one or two florescent bulbs to illuminate the screen from behind, while LED backlit screens use a number of uniformly placed LEDs. For this reason LED screens are brighter, more uniformly lit, consume less energy and have a thin physical profile. However, as any new technology, they cost more.
Other than that, when talking screen about specifics, you should also pay attention to resolution and surface type (matte or gloss). Resolution depicts the number of pixels on a screen; more resolution means more details and sharper images. Screens with a matte surface are good if you are going to use it outside or in a brightly lit office room, because they don’t have a reflection, on the other hand glossy screens produce more vibrant colors, but glare could be a problem. Nevertheless I personally like glossy screens because they tend to produce more rich and vibrant colors.
Every notebook now has an integrated wireless adaptor, and you have little or no control over configuring it. Most notebooks support G (54Mbps / 35m range) standard however new notebooks support N (~300Mbps / 70m range) standard. If you have the option to choose then N is obviously better, N cards have backward compatibility with G and other older standards (i.e B, A) therefore even if you don’t have a wireless G router with you now, it is ok to buy a N card.
most notebooks have a DVD burner, but newer ones are even have BluRay drives. However they will increase the price of the notebook by about $300. Therefore I don’t think still a BluRay drives are worthy for notebooks, especially if you don’t have a large high resolution screen and a digital video output (DVI, HDMI).
Bluetooth will let you connect Bluetooth enabled devices wirelessly to your notebook. I think this is an essential feature nowadays because lot of accessories now support Bluetooth i.e Mobile phones, Mice, Keyboards, headsets, webcams etc..
I think that covers almost all the major components of a computer and I hope it was useful to you to have at least a basic understanding of some of the technical terms. If you have questions or comments please post, I will do my best to reply them. Next time lets talk about how to configure a notebook to match your needs and your budget.