Intel's processor history: the path from the Intel 4004 to the Pentium 4

Intel's processor history: the path from the Intel 4004 to the Pentium 4

1997: Intel's new workhorse: The Pentium II

As early as May, Intel introduced its new processor family, the Pentium II, before the public. The first generation of the Pentium II was codenamed 'Klamath' and was produced with clock frequencies of 233, 266 and 300 MHz. The Pentium II processors combined the new MMX technology with the advantages of the Pentium Pro, which was not very well received at the time. Externally, the Pentium II clocked at 66 MHz, had 7.5 million transistors, were manufactured using 0.35 µm technology and again had a 512KB L2 cache. In terms of first-level cache, the Pentium II had to admit defeat to AMD's competitor, the AMD K6. This decreedunlike the Pentium II, which is only equipped with 32KB, already over 64KB. As with the Pentium 200 for the first time, Intel used an SEC housing ('Single Edge Contact') for the Pentium II, which combines the CPU and the second-level cache in one housing and enables installation with a simple plug connection.

With the Pentium II, Intel also introduced the new slot 1 at the same time and turned away from socket 7. Last but not least, it was hoped that this step would take the socket and thus AMD's basis for further advancement. Like the Pentium Pro, the Pentium II used the dual independent bus architecture (DIB). In contrast to its predecessor, however, it only accessed the second-level cache with half the internal CPU speed; the Pentium Pro did this with full CPU speed. Intel carried out the most extensive price reduction up to that point in August, when they reduced the price of the Pentium II 300 by 57 percent. The production of processors without MMX technology was discontinued at the same time.

The second generation of the Pentium II was codenamed 'Deschutes'. This second generation was used at clock rates of 333-450 MHz. The only big internal difference to the first generation was the reduction of the manufacturing process to 0.25 µm. Intel also brought out even older models with the new core, so that the two models with 266 and 300 MHz were offered in both a 0.35 and 0.25 µm version. Up to the Pentium II with 333 MHz, the CPUs of the second generation were still operated with a 66 MHz front-side bus (FSB). All subsequent models already use a 100 MHz FSB.

But that wasn't all that should change with the second generation. The processor voltage could be reduced from 2.8 volts in the Klamath to 2 volts in the Deschutes. In addition, the consumption of the Klamath was above that of theDeschutes and thus the heat development was greater. The Klamath still consumed 32 watts at 300 MHz, but the Deschutes only consumed 15 watts at 333 MHz.

The first picture shows the processor markings on the housing of the Pentium II. All important information such as clock frequency, L2 cache size, voltage and bus clock were placed directly on the SECC housing by Intel so that the customer could quickly identify the CPU.

Intel Pentium II
Intel Pentium II

Different RAM modules were also used for the L2 cache. While the Klamath was still equipped with four components with 6.5 or 7 ns, the Pentium II 333 only had two components, each addressed with 5.5 ns, and the Pentium II 350 and 400 with also two components, which were addressed with 4.4 ns. The modules of the Klamath could only be operated with up to 150 MHz, while the modules of the Pentium II 333 could be clocked with 180 and those of the Pentium II 350 and 400 even with 200 MHz. This information played an important role, especially for enthusiastic overclockers, as successful overclocking often depended on the L2 cache, which usually more than the processor could cope with a higher clock.

Intel Pentium II
Intel Pentium II

The Pentium II finally made its debut in August 1998 with 450 MHz. Except nowwith a maximum of 225 MHz clocked, but still 4.4 ns fast, L2 components have not changed compared to its predecessors.

If you talk about the Pentium II, you have to mention a chipset in the same breath as it: Intel's BX chipset. It has certainly made a major contribution to the success of the Pentium II and Pentium III, as it has a lot of features and also convinces with its very good compatibility and stability, which some chipsets still cannot achieve today. It has made a really unique reputation for itself over the years and not only Intel users still rave about its skills.

Finally, we have the different versions of the Pentium II for you in a table summarized:

Clock frequency front side bus multiplier L2 cache L2 cache clock DIE size Format 450 MHz 100 MHz 4.5 512K 225 MHz 0.25 µm SECC 400 MHz 100 MHz 4.0 512K 200 MHz 0.25µm S.E.C.C. 350 MHz 100 MHz 3.5 512K 175 MHz 0.25 µm S.E.C.C. 333 MHz 66 MHz 5.0 512K 166 MHz 0.25 µm S.E.C.C. 300 MHz 66 MHz 4.5 512K 150 MHz 0.25 µm S.E.C.C. 300 MHz 66 MHz 4.5 512K 150 MHz 0.35 µm S.E.C.C. 266 MHz 66 MHz 4.0 512K 133 MHz 0.25µm S.E.C.C. 266 MHz 66 MHz 4.0 512K 133 MHz 0.35 µm S.E.C.C. 233 MHz 66 MHz 3.5 512K 116 MHz 0.35 µm S.E.C.C.

On the next page: 1998: Intel's budget CPU: The Celeron