Notebook versus Desktop PC
Current high-end DTR (Desktop Replacement) notebooks should be capable of replacing a desktop PC (as the name implies). Throughout the last years the performance of the components used in notebooks approximate those of desktops. Nowadays they are already capable of providing performance for every field of operation.
A few years ago it was still unimaginable that notebooks could come close to the performance of desktops. Current top processors and video cards for notebooks technologically even out desktops components. Still, the cooling system and the energy demand of high-end desktop computer is superior.
Processor
- The Dell XPS M1710 is a powerful example of DTR notebooks with fast (even potentially overclocked) Dual Core processors
Current mobile processors, e.g, Core 2 Duo and Turion X2, run with slightly lower clock rates in notebooks (e.g., Core 2 Duo: 2,93 GHz versus 2,33 GHz for the notebook). Furthermore, their kernel voltage is reduced and they provide further energy saving mechanisms (whereby performance possibly suffers). Therefore, even processors with the same clock rate are maybe slightly slower than desktop processors, however, they are superior regarding energy demand.
At the time of writing 4-core processors (Quad Core) are not yet available for notebooks (despite you would use desktop processors) and it is even not planned to make them available for notebooks in the short run. They still demand too much current, and emit far too much waste heat, and are, therefore, not yet adapted for use in small cases like those of laptops.
Still, the performance of current high-end notebook CPUs is sufficient for running all applications (and games) fluently.
More information about notebook processors can be found in our comparison of processors and in our sortable benchmark list of mobile CPUs.
Video Cards
High-end desktop video cards, e.g., 8800 ,or X1950 (in SLI mode) are clearly faster than high-end notebook video cards, because they are run at higher clock rates. Also regarding this matter, the performance is limited by energy demand and waste heat. Video cards with more than 100 Watt power output, cannot be efficiently cooled down, and would also empty the battery in no time.
Today, notebook models still lag behind regarding DirectX 10 features, but you can expect that more and more notebook video cards with DX10 features will be available soon. Top notebook video cards, e.g., the NVIDIA GeForce Go 7950 GTX (or SLI) still provide sufficient power for current games (see also our comparison of video cards and the sortable benchmark list of mobile GPUs).
- 2 video cards linked together by SLI are also available for notebooks for high performance (here Nexoc Archimedes E407).
Other Components
Memory - most modern notebooks have two (mostly easy to access) memory slots. This is half of desktop PCs, which in the majority provide 4 memory slots. Also regarding clock-rate and timing the smaller notebook SO-DIMMs are slightly slower than desktop memory chips.
However, the main difference can be experienced at hard disks. Today the mainly used 2,5" hard disks are still clearly slower that the 3,5'' hard disks of desktops. Also regarding capacity the smaller notebook hard disks lag behind desktop hard disks. However, big 17 - 19" DTR notebooks offer the opportunity to link two 2,5" hard disks together by RAID. This makes a considerable performance possible, but has disadvantages regarding data security (if one of the two hard disks fails, all data are lost).
You'll also notice the energy and space saving at the display. The panels used in notebooks are clearly worse regarding all aspects than desktop displays. The vertical and horizontal stability to the vantage point could generally be better and also the maximum brightness is clearly behind those of desktop displays. However, an external monitor can be connected to nearly all notebooks in order to resolve this shortcoming.
Verdict
High-end notebooks are unlikely to catch up with high-end desktop computers, because it is more difficult to cool them down, because of their limited size. Despite this, notebooks have a considerable performance, which is comparable to upper middle class desktop computers. This makes it possible to handle nearly all fields of applications. Especially mobile game computers are possible since the introduction of fast notebook video cards. Furthermore, a notebook is a balanced complete system, which is optimized regarding energy demand (75-150W compared to 300-500W of desktops), noise emissions (in average), and, most important, mobility.
