The Masterplan for ICT in education of Cambodia contains planning for massive deployments of computers in the Cambodian education system. In order to make this exercise a sustainable one, it is necessary to take great care in the selection of the hardware to be used in this. As the developments of computer hardware are going very fast, it is not doable to mention exactly what type of computer equipment is needed. In stead, this document intends to give some general recommendations on computer hardware.

Cambodia is a tropical and developing country, two aspects which have to be taken into account when buying hardware for the education system. First of all, Cambodia is tropical, which means that it can be very hot at some times (+40° C), humidity approaches 100% at some times, and dust is a problem in the dry season. These environmental factors ask for specific and robust hardware. Secondly, Cambodia is a developing country, with a number of elements of it being important when considering hardware: Cambodia is just entering the digital age, which means that a lot of knowledge and experience is lacking. Furthermore,only 19% of rural Cambodia is connected to the electricity grid. The 19% which have electricity have to pay a lot for it: There are places where the price of electricity is $1,- per KW/h. A last, obvious, aspect of Cambodia being a developing country, is the fact that it has serious budget constraints, both at the national level and at the school level.

The specific context described above call for a hardware solution which is suitable to overcome the problems stated. This means that this solution should be low cost on both purchase and running costs, and low maintenance. At the same time, it should be able to run all the applications which are typically needed in an educational environment. How this can be achieved is described below.

As stated above, the hardware should be cheap to purchase, cheap to run and easy and cheap to maintain. In order to reach those goals, the different hardware elements of a computer are described below:

The performance of modern desktop machines is always increasing. Every few months new models come out, with even more MHz or memory. And so is their power consumption. Would a PC of the early 2000's (say an early Pentium III) consume only around 40 or 50 Watts, a modern PC which are for sale nowadays typically consume around 150-200 Watts! These machines are now so powerful that they are being idle most of the time, which is a waste of energy.

Luckily, there are also specific low power solutions available in the market today, and more developments are on the horizon. In the table below an overview is given of present low power CPU's available in the market today, and the future low power CPU's coming. Note that this is not a complete list: The CPU's presented below are powerful enough to run applications for school purposes smoothly, and are based on the x86 and x86-64 platforms and are cheap (below $100,-)

The table here above is just to show that all manufacturers have low power CPU's. To make them suitable for education, and to say something useful about power consumption, the CPU's need to be mounted on a motherboard. The cheapest option available in the market today, are the CPU's discussed above, mounted on a so called “mini-ITX” motherboard. Mini-ITX is a form factor for motherboards of 17×17 cm. The manufacturers sell the small boards with a CPU soldered onto it. Many boards can be found for under $100,-. Research has shown that it is very well possible to get boards with these CPU's which will consume in idle mode less than 30 Watts. It is furthermore recommended to get boards with CPU's which are completely fanless. Fans are susceptible to breakage (especially in dusty conditions) and should be avoided as much as possible.

RAM is cheap and readily available. It doesn't come with fans or other moving parts, and their power consumption is negligible. It is recommended to use at least 512 MB.

Traditional power supplies found in normal desktop machines have a couple of problems: First of all, they are very inefficient. Efficiency levels are typically around 60%. Secondly, they are usually designed to supply at least 150 Watts of power, which is too much for the low cost computers we are recommending here. Drawing only 30 Watts from a 150 Watt power supply will also lower the efficiency even more. Last disadvantage about these power supplies is that they have fans to cool them, and fans can break easily in dusty conditions. A recommended solution for these problems are DC-DC power supplies, with an external power supply. The external power supply is 12 Volts, which means that they can also be used in combination with car batteries. When using solar power, no more conversion to 220 Volts is needed.

Harddisks which are produced for laptops (2,5”) consume less power than 3.5” big harddisks, which is the reason we recommend them here. Solid state disks (SSD's) are harddisks with no more moving parts. Their life expectancy is longer, and they consume less energy. These are already available in the market, but are too expensive yet. They are preferred above normal harddisks because of their low power consumption and longer life expectancy due to no moving parts, and should replace the normal harddisks as soon as they have become cheaper.

With the introduction of the mini-ITX platform, it now is also possible to use much smaller computer casings than normal ones. This saves a lot of desktop real estate (so students can actually see the teachers!). There are several solutions available in the market. They often come with an included DC-DC power supply and an external 12 Volt power supply. This is very convenient. Care should be taken that it is easy to do maintenance to these casings. It's also recommended to get casings which can be locked or screwed to a table or a screen to prevent theft.

Old CRT screens consume two to three times more energy than LCD screens. It is therefore recommended to get LCD screens. There is very little variation between the LCD screens themselves. As Khmer writing needs a lot of spacing between the sentences (because some letters can be stacked) a high resolution screen is to be preferred (1280-1024). On a 15” screen this will be not so easy readable, therefore 17” is preferred.

Availability of hardware is of course a matter of scale. Currently, it is very difficult to obtain low cost hardware in computer shops in Phnom Penh. The only motherboard available is the 1,5 Ghz VIA brandless board. Intel also has an office in Phnom Penh, making it easier to obtain Intel boards. Small scale deployments will be difficult when using local shops. However, large scale deployments can be a lot easier, since the buyer can contact manufacturers directly. Specialised designs are possible with big purchases (for instance for casings, which could be adapted to the local situation). Since all computer manufacturers are located in Asia, getting hardware for large scale deployments will be relatively easy.

Getting hardware for the Cambodian education system is basically just common sense. Low power low cost hardware is readily available in the (international) market. There are many motherboards available on the mini-ITX platform which consume less than 30 Watts. So, in order to select hardware for computers in Cambodian education, the following criteria have to be met:

Low power: The whole system (including screen) should consume less than 60 Watts in idle mode The casing should be protected against theft, and be small The computer should be equipped with a DC-DC power supply, and a 12 Volt external connector The harddisk should be 2.5” (laptop harddisk) and as soon as Solid State Drives (SSD's) become cheaper, they should replace the normal harddisks Fanlessness: An effort should be made to have zero fans in the system. There should be at least 512 MB of RAM in the system The CPU should be at least as powerful as the CPU's listed in the table above