Intel Atom processors

Intel Atom is the brand name for a line of ultra-low-voltage x86 and x86-64 CPUs (or microprocessors) from Intel, used mainly in netbooks, nettops (table top computers used usually for net surfing), embedded application ranging from health care to advanced robotics and Mobile Internet devices (MIDs). Intel Atom processors are based on the Bonnell micro-architecture. You can read more on Atom processors on Wikipedia.

Atom processor family list can viewed on ark Intel site.

Intel Atom  N2800 (Third generation Atom processor)

• Frequency                                   1.86 GHz
• Manufacturing process                 0.032 micron (32 nm)
• Number of cores                          2 (4 Threads)
• Level 2 cache size                       Shared 1 MB
• Thermal Design Power                 6.5  W

Brief history of Intel processors

If you go through the history of intel processors you will find that starting form intel 4004  (first 4 bit complete CPU on one chip) to Intel 80386 to pentium P5 (microarchitecture) the processors where in order execution processors (executed instructions in the order they are provided). As processors speed continued to increase developers felt the need to utilize CPU time efficiently so they developed out-of-order execution, speculative execution more pipelining.

Intel Atom N280 (First Generation)

In out-of-order execution if one instruction requires operand to be fetched from memory then CPU can execute next instructions in the instruction queue which are ready for execution. The processor logic is designed such that instructions are re-ordered after execution of all instructions in queue are done. Thus processor clock cycles are not wasted for waiting for operands to be fetched from memory.

More pipelining increases the number of instructions that can be processed per clock cycle. Speculative execution and branch prediction helps processor to execute instructions which are more likely to be executed next. After execution of these the results are discarded if they are not needed (depending on branching condition) otherwise they improve efficiency of processor greatly.

As Atom processors need to be very power and cost efficient they do not use out of order execution. Even so they give better performance than 5 years or more old Pentium processors at same clock speeds. That is why they are used in low cost netbooks.