The question is if a desktop computer and a laptop both of same configuration say(2.0ghz dual core,1GB ram)-- are they of same performance?---THE Answer is no.--READ DETAILS// ধরুন একটি ডেস্কটপ computer(2.0ghz dual core, 1GB ram) এবং একটি ল্যাপটপ একই(2.0ghz dual core, 1GB ram)।এখন প্রশ্ন তারা একই কার্যকারিতার কিনা।----একই কনফিগারেশনের যদিও, ল্যাপটপ ক্ষুদ্র আকার, কম শক্তি ব্যাবহার, বহন যোগ্যতা লাভ করতে ডেস্কটপের তুলনায় দুর্বল হয়।- Motherboard
- Central processing unit..
- Memory ram.
- Expansion card.
- Power supply..
- Battery.
- Desktop computer has expansion slot to add a new device
- Laptop has no expansion slot (to expand require external port)
Central processing unit (CPU) – Laptop CPUs have advanced power-saving features and produce less heat than desktop processors, but are not as powerful.
--There is a wide range of CPUs designed for laptops available from Intel (Pentium M, Celeron M, Intel Core and Core 2 Duo), AMD(Athlon, Turion 64, and Sempron), VIA Technologies, Transmeta and others. On the non-x86 architectures, Motorola and IBM produced the chips for the former PowerPC-based Apple laptops (iBook and PowerBook).
---Some laptops have removable CPUs, although support by the motherboard may be restricted to the specific models.In other laptops the CPU is soldered on the motherboard and is non-replaceable.
A notebook processor is a CPU optimized for notebook computers.One of the main characteristics differentiating notebook processors from other CPUs is low-power consumption.
A microcontroller (also microcontroller unit, MCU or µC) is a small computer on a single integrated circuit consisting of a relatively simple CPU combined with support functions such as a crystal oscillator, timers, watchdog, serial and analog I/O etc. Program memory in the form ofNOR flash or OTP ROM is also often included on chip, as well as a, typically small, read/write memory.
A PIC 18F8720 microcontrollerin an 80-pin TQFP package.
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A SO-DIMM, or small outline dual in-line memory module, is a type of computer memory built using integrated circuits.
PC6400 DDR2 SO-DIMM
SO-DIMMs are a smaller alternative to a DIMMS, being roughly half the size of regular DIMMs. SO-DIMMS are often used in systems which have space restrictions such as notebooks, small footprint PCs (such as those with a Minitex mother board), high-end upgradable office printer, and networking hard ware like router .
A DIMM, or dual in-line memory module, comprises a series of dynamic random access integrated circuit.
Expansion cards – A PC Card (formerly PCMCIA) or ExpressCard bay for expansion cards is often present on laptops to allow adding and removing functionality, even when the laptop is powered on. Some subsystems (such as Wi-Fi or a cellular modem) can be implemented as replaceable internal expansion cards, usually accessible under an access cover on the bottom of the laptop. Two popular standards for such cards are MiniPCI and its successor, the PCI Express Mini.
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PCI card is used to add a new device to computer internally (sound card,vga card.).This card is set in internal expansion slots provided in the motherboard.
PC card is external device.Can be connected through external port such as USB port.
In desktop computer there is slotted internal Expansion card to add new device. so it can take both PC and PCI card
In laptop there is no slot,addition of device is done by external pc card,that must be connected through USB or other port.That is it can take only PC card.
Expansion cards via one of:
---PCI bus slot
---AGP bus slot
---PCI Express bus slot
---SA bus (on older motherboards) slot
The ASUS A8N VM CSM with expansion slot
A PCI-X Gigabit Ethernet expansion card
Three 5V 32-bit PCI expansion slots on a motherboard
Fitting an expansion card into a motherboard in desktop computer
A pc card with USB cable.Functions as a WiFi MODEM. connected through USB port
Huawei CDMA2000 Evolution-Data Optimized USB wireless modem
A pc card .Functions as a INTERNET MODEM
A mobile phone can be used as a wireless modem.Connected through USB port
A switched-mode power supply (SMPS) works on a different principle. AC mains input is directly rectified without the use of a transformer, to obtain a DC voltage. This voltage is then sliced into small pieces by a high-speed electronic switch. The size of these slices grows larger as power output requirements increase.
The input power slicing occurs at a very high speed (typically 10 kHz — 1 MHz). High frequency and high voltages in this first stage permit much smaller step down transformers
than are in a linear power supply. After the transformer secondary, the AC is again rectified to DC. To keep output voltage constant, the power supply needs a sophisticated feedback controller to monitor current draw by the load.
A computer's switched mode power supply unit
Modern switched-mode power supplies often include additional safety features such as the crowbar circuit to help protect the device and the user from harm.
Battery – Current laptops utilize lithium ion batteries, with more recent models using the new lithium polymer technology. These two technologies have largely replaced the older nickel metal-hydride batteries.
--- Typical battery life for standard laptops is two to five hours of light-duty use, but may drop to as little as one hour when doing power-intensive tasks.
---A battery's performance gradually decreases with time, leading to an eventual replacement in one to three years, depending on the charging and discharging pattern.
---This large-capacity main battery should not be confused with the much smaller battery nearly all computers use to run the real-time clock and to store the BIOS configuration in the CMOS memory when the computer is off.
---Lithium-ion batteries do not have a memory effect as older batteries may have. The memory effect happens when one does not use a battery to its fullest extent, then recharges the battery. New innovations in laptops and batteries have seen new possible matchings which can provide up to a full 24 hours of continued operation, assuming average power consumption levels. An example of this is the HP EliteBook 6930p when used with its ultra-capacity battery.
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Lithium-ion polymer batteries, polymer lithium ion, or more commonly lithium polymer batteries (abbreviated Li-poly, Li-Pol, LiPo, LIP, PLI or LiP) are rechargeable batteries (secondary cell batteries). Normally batteries are composed of several identical secondary cells in parallel addition to increase the discharge current capability
Lithium-ion batteries (sometimes abbreviated Li-ion batteries) are a type of rechargeable battery in which a lithium ion moves between theanode and cathode. The lithium ion moves from the anode to the cathode during discharge and in reverse, from the cathode to the anode, when charging
- Battery model /quality (HP EliteBook 6930p can run 24 hour)
- Age of battery
- Task or operation of laptop.That is when there is heavier task such as playing games,dvd operting in dvd rom,portable device attached (external keyboard,mouse).Battery discharges faster
Video display controller – On standard laptops the video controller is usually integrated into the chipset. This tends to limit the use of laptops for gaming and entertainment, two fields which have constantly escalating hardware demands.
--Higher-end laptops and desktop replacements in particular often come with dedicated graphics processors on the motherboard or as an internal expansion card. These mobile graphics processors are comparable in performance to mainstream desktop graphic accelerator boards.
There are essentially two different types of graphics processors that can be found in computers in general: integrated and dedicated.
Integrated graphics parts are a part of the motherboard, of the system itself. Motherboards have at least one core chip called a Northbridge, which controls functions like RAM, the PCI Express bus, and how the rest of the computer interfaces with the processor . Integrated graphics have the graphics core built into the northbridge, and they share their video memory off of RAM. As a result, they eat a little bit of the bandwidth your system is using to interface with the RAM, and reduce the amount of system RAM available. Most integrated parts tend to share that memory dynamically, though, meaning they only take what they need. Only the Radeon Xpress integrated parts have their own memory, and only in AMD systems.
Despite the shared memory, there are many benefits to integrated parts. They improve battery life, reduce the cost of the notebook, and allow the notebook to run cooler as it doesn't need to cool an extra dedicated chip.
The flipside is that they generally offer very poor performance for gaming, with the fastest integrated parts still being beaten handily by the slowest dedicated parts.
And speaking of dedicated parts: a dedicated graphics core is separate from the northbridge, and has its own video memory. This means it doesn't siphon off the system RAM, although some parts (typically lower end) do dynamically share from system RAM as needed, though only when it would improve performance (and you'll never see them do so in regular Windows operation, only during gaming).
Dedicated graphics parts will always outperform integrated parts, albeit in varying degrees. If you're going to game on your system, you'll need one of these.
The problem with dedicated parts is that they drive up the cost of the notebook, can increase the temperature (as they need to be cooled by themselves), and reduce the battery life. Additionally, due to the power draw and cooling issues, dedicated parts seldom find themselves in ultraportable notebooks.
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