Pentium vs Core 2 Duo
Intel has gone through more than a few lines of microprocessors, probably the biggest of which is the Pentium series and was released right after the 486 series; spanning over a decade and going from just over a hundred megahertz to around 4 gigahertz. The Core 2 Duo is a more recent line of microprocessors that succeeded the Core line. Aside from being newer, the Core 2 Duo is also more specific as it only relates to the dual core microprocessors of the Core 2 series. There are also Core 2 microprocessors with 4 cores and are appropriately called Core 2 Quad. One the other hand, Pentiums were mostly single core microprocessors with only the latest versions being dual cores; no quad core Pentium was ever released.
Although you might think that Core 2 Duos would have higher clock speeds as they are newer, you would be gravely mistaken as some of the last single core Pentium processors have much higher clock speeds than Core 2 Duos. The limitation in the clock speeds of Core 2 Duos come from having two microprocessors in one package and generating roughly twice the amount of heat. Heat needs to be dissipated properly or it will damage the microprocessor. To keep the heat generated at acceptable levels, it is necessary to scale down the clock speeds of the Core 2 Duo processors.
Although there are dual core Pentiums, called Pentium Ds, they do not share the same architecture as the more complex Core 2 Duos. Basically, the Pentum Ds were basically two Pentium 4s placed side by side in the same package. The Core 2 Duos have an improved architecture that was based on the older Pentium M processor, which in turn was based on the Pentium 3.
Despite being based on an older architecture, the Core 2 Duos are still far ahead of the Pentiums in terms of performance due to having two cores and being optimized to take advantage of those two cores.
Summary:
1. Pentium is a line of microprocessors that followed the 486 line while Core 2 is the successor to the Core line.
2. Pentiums are either single core or dual core while Core 2 Duo are dual core processors
3. Core 2 Duos have a lower clock speed than the fastest Pentiums
4. Core 2 Duos and Pentiums do not share the same architecture
5. Core 2 Duos provide significant performance advantage over Pentiums