Pentium® Pro
the very first pentium microprocessor (80586) with p5 architecture, which came out in 1993, did not have a logo.
the first logo for pentium brand was released when intel introduced the new "Pentium Processor with MMX Technology" or just "Pentium MMX" in 1996. the clock frequency of pentium mmx series varied from 66MHz to 300 MHz. the production line was cut down in 1999.
at the same time, intel also gave a logo to their high-end product series "Pentium Pro MMX Technology", which was based on a different p6 architechture. pentium pro series were clocked at 150Mhz to 200MHz respectively. the production started in 1995 and ended in 1998 when intel introduced the "pentium ii xeon" as the replacement for high-end processors.
Pentium® II
later in 1997, intel introduced the "Pentium II" processor. the logo wasn't very different from the previous pentium's. however, the name "pentium" had become famous by then. pentium ii processors ran at the clock of 233MHz to 450MHz. it was replaced by the pentium iii series.
Pentium® III &
Mobile Pentium® III - M
with the new SSE instruction set added in, intel renamed the new mainstream desktop processors as "Pentium III". it was one of the most successful pentium series in intel's history. the production started in 1998 and ended unexpectedly in 2001. it has a variation of speeds from 450MHz to 1.4GHz.
during that period, laptop computers started to become popular and there was a high demand of low power-comsuming processor; as a result, intel created "Mobile Intel Pentium III-M" brand.
.
.
.
.
Pentium® 4 ,
Mobile Pentium® 4 - M,
Pentium® 4 supporting Hyper-Threading Technology &
Pentium® 4 Extreme Edition
intel made their biggest mistake ever in 2001. they introduced the "Pentium 4" processor with the brand new netburst architecture and promised that it would be much better than the previous pentium iii. however, all kinds of benchmark testing and user reviews had proved them wrong. the earliest pentium 4 processors with socket-423 interface performed way worse than the latest pemtium iii; plus it required the very expensive Rambus DRAM. customers continued to look for pentium iii, so that intel had to cut down the pentium iii in order to push pentium 4.
some years later intel realized their mistake and stepped back to pentium iii. but of course they can't use the name pentium iii again. guess what it became?
follow intel's tradition, the pentium 4 series also had a individual production line for laptop computers; the name was "Pentium 4-M". soon intel noticed that the stupid netburst architecture cannot avoid but to comsume a lot of energy & produce a lot of heat. they then replaced the pentium 4-m with the famous "pentium m" in 2003.
meanwhile the drama of pentium 4 on desktop platform went on. intel added in the "hyper-threading" technology into the pentium 4 processors, and they funnily put the two letter HT into the original pentium 4 logo. there we have another logo for the "Pentium 4 with Hyper-Threading Technology" or simply, Pentium 4 HT.
to compete with AMD's Athlon 64 FX, intel rushed out another funny version of pentium 4, with incredibly high frequency and doubled L2 cache. not to mention about the performance, any way, the name was "Pentium 4 Extreme Edition", or sometimes, Pentium 4 EE.
pentium 4 series was ended in 2008. its frequency vary from 1.3GHz to the crazy 3.8GHz. some of the later ones even supported 64bit processing. however it's super high frequency did bring up its performance due to it's low effeciency.
.
2006 new logos: 
.
.
.
.
.
Pentium® M
in 2006, intel came up with the new logos for all its still active production lines. so what happened to the Pentium 4-M? as i mentioned just now, it was replaced by "Pentium M" in 2003. intel finally stopped using numbers to name different series of pentium processor. the letter "M" stands for "mobile". and in fact, from pentium m, intel began to abandon the non-effecient netburst architecture and started all over again from pentium iii. the pentium m ran at a much lower clock frenquency (from 900MHz to 2.26GHz) but was way faster than pentium 4. together the "Centrino" technology, pentium m had become the most successful mobile processor in history. in 2008, pentium m was replaced by "core" series and "atom" series.
.
original logo: 
2006 new logo: 
.
.
.
.
Pentium® D &
Pentium® Extreme Edition
while pentium m was gaining huge success in mobile market, intel's desktop processors remained in disasters. high power comsumption and low effeciency stopped intel from increasing the pentium 4's clock frequency. but intel had another idea: instead of raising the frequency of one processor, they increased the number of processors. "Pentium D", that's how the trend of dual-core processor started. the pentium D processor started in 2005 with 2.66GHz and ended in 2008 with 3.73GHz.
same as pentium 4, it also had a extreme edition "Pentium Extreme Edition", or Pentium XE. Later, it was replaced by "Core 2" series.
.
original logos: 
2006 new logos: 
.
.
.
.
.
Pentium® Dual-Core
after intel successfully introduced the pentium-m based "Core 2" series, pentium was used as a simplified version of core 2, like how celeron used to be the simplified version of the previous pentium. the dual core pentium was no more "pentium D" but "Pentium Dual-Core".
.
.
.
.
Intel® Pentium® Processor Family
the "pentium dual-core" brand didn't keep its logo for long. in 2008 intel assigned a family logo for all pentium series processors, including pentium iii, pentium 4, pentium m, pentium D & the new pentium dual-core. soon in 2009, followed by the releasing of core series new logos, a horizontal version of the pentium family logo was also introduced. the new pentium dual-core produced in mid 2009 will be given the horizontal logo instead.
.
2008 family logo: 
2009 new logo: 
.
.
.
-
