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Intel's 15 Most Unforgettable x86 CPUs

Pentium Pro: The First To Handle Over 4 GB Of Memory

The Pentium Pro, released in 1995, was the first x86 CPU able to manage more than 4 GB of RAM using Physical Address Extension (PAE), 36-bit address size, and thus 64 GB. An interesting point is that this processor was also the first P6 (the architecture the Core 2 processors are loosely derived from) and also the first x86 to include a Level 2 cache on the processor instead of on the motherboard. In fact, between 256 KB and 1 MB of cache were placed next to the CPU, on the same socket, making the L2 cache on-package as opposed to on-chip, clocked at the same frequency as the CPU.

This processor also had a bit of a performance issue. It ran great in 32-bit applications, but was much slower with software still written in 16 bits (like Windows 95). The cause was simple: access to 16-bit registers caused problems with management of the (32-bit) registers, which canceled out the advantages of the Pentium Pro’s out-of-order architecture.

Code nameP6
Date released1995
Architecture32 bits
Data bus64 bits
Address bus36 bits
Maximum memory64 GB
L1 cache8 KB + 8 KB
L2 cacheexternal, 256-1024 KB (CPU frequency)
Clock frequency150-200 MHz
FSB60-66 MHz
FPUbuilt-in
SIMDN/A
Fabrication process600-350 nm
Number of transistors5,500,000 + cache
Power consumption29-47 W
Voltage3.3 V
Die surface area306-196 mm² + cache
ConnectorSocket 8

The cache measured 202 mm² (256 KB at 500 nm), 242 mm² (512 KB at 350 nm), or 484 mm² (1 MB at 350 nm). The number of transistors in the cache was 15.5 million (256 KB), 31 million (512 KB), or 62 million (1 MB).

  • Arkz
    great article with only a few slight errors (like saying the core2duo has 1-4 cores... i don't think there's a 1 cored version lol)

    Looking forward to the AMD article.
    Reply
  • aleluja
    To correct you. Core 2 Duo has ONLY 2 cores, not more, not less.
    Core 2 Quad, has 4 cores and Core Solo has 1 core.
    Reply
  • @Arkz

    Yes there is a singal core,

    http://en.wikipedia.org/wiki/List_of_Intel_Core_2_microprocessors#Single-Core_Mobile_processors
    Ok it is not under the same branding but it is part of the same microarchitecture
    Reply
  • Yuka
    I might be wrong, but i resemble that the Pentium 166 (32bits adress bus and all) had support for 4Gb of memory. I remember IBM sold it's top line (at that time) with 64Mb support (even with SDR PC100/66 support). Correct me if i'm wrong please.
    Reply
  • neiroatopelcc
    The core 2 does supply 1-4 cores - 2 cores per die, where one might be disabled, and one or two dies on a socket. It's no less right to call a core2duo a cpu with 1-4 cores, than it is to put the pentium d on the same page as a single core prescot, as it's the very same principle.
    Reply
  • cangelini
    Arkzgreat article with only a few slight errors (like saying the core2duo has 1-4 cores http://en.wikipedia.org/wiki/Coree ... i don't think there's a 1 cored version lol)Looking forward to the AMD article.
    Thanks for the heads-up! I tweaked that passage to better represent the Core 2 architecture's available configurations!
    Reply
  • randomizer
    vosesterOk it is not under the same branding but it is part of the same microarchitecture Exactly. The article says:

    ArticleThere are many versions of the architecture, resulting in configurations with a different number of cores
    There is no mention of the branding, so there is no actual error there, just misinterpretation.
    Reply
  • ImSpartacus
    Arkzgreat article with only a few slight errors (like saying the core2duo has 1-4 cores... i don't think there's a 1 cored version lol)Looking forward to the AMD article.
    http://www.newegg.com/Product/Product.aspx?Item=N82E16819116039
    Yes, it isn't called a "Core 2 Duo," but it uses the Core architecture and only has a single core enabled.

    But I will have to say, there aren't any 3 core models...
    Reply
  • magicandy
    Good to hear you're not only doing an AMD article, but an ATI one as well (in response to the Nvidia article you did earlier, assuming). A sign of class from the new Tom's is a welcome one.
    Reply
  • harrycat88
    I wish they would get rid of those stupid SNAP Linkbubless and Inteltex misguiding links. Who ever invented those stupid annoying double lined text popups should have been burned at the stake
    Reply