Threads

• The HP 620's Intel Core processor has two threads -- sections or streams of instructions that allow processors to perform different tasks on the same process.. In comparison, the HP 630's Intel Core processor can have two or four threads, depending on the specific model. Having four threads -- in comparison to two -- allows a processor to complete processes more rapidly.
  
  

Clock Speed

• Also known as frequency, clock speed refers to how frequently a processor can generate electronic pulses for executing instruction sets. A faster clock speed allows a processor's host computer to perform operations more rapidly. An HP 620's Intel Core processor tends to have a slower clock speed than a HP 630's Intel Core processor. However, depending on the specific model of processor that the HP 630 uses, the clock speeds of the 620 and 630 processors could be equal. The 620's Intel Core processor has a clock speed of 2.10GHz, which means the processor can complete 2.10 billion cycles per second. In comparison, the 630's Intel Core processor can have a clock speed of 2.10GHz, 2.20GHz, 2.30GHz, 2.50GHz or 2.60GHz.
  
  

Cache

• The HP 620's Intel Core processor has an L2 cache size of 2MB. In comparison, the HP 630's Intel Core processor can also have an L2 cache size of 2MB or an L3 cache size of 3MB, depending on the specific model. A cache is an integrated -- or on-chip -- storage space that provides a processor with commonly accessed data. A cache frees a processor from the time-consuming process of continually sending and receiving data through a computer's system memory. While an L2 cache is faster than an L3 cache, an L3 cache can store more data.
  
  

Lithography

• Lithography refers to the printing of a processor's circuit board and is an indicator of a processor's overall size. While the HP 620's Intel Core processor has a lithography of 45 nm, the HP 630's Intel Core processor can have a lithography of 45 nm or 35 nm, depending on the specific model.
  
  

Socket

• The HP 620's Intel Core processor connects to a host computer's motherboard using socket PGA478, which has 478 connector pins. In comparison, the HP 630's Intel Core processor can connect to a host computer's motherboard using a socket PGA478, a 988-pin socket PPGA988 or a 1,023-pin socket FCBGA1023, depending on the specific model.