I5, processor Intel

Released in September 2009, the I5 is replacing the Quad and Core2 Duo as Intel mid-range processor (the high end is I7). It uses the same architecture Nehalem but limits some functions in the model than maintaining a quad-core, 32 modes / 64-bit (always with Intel EM64T instructions already in the latest Core2).

Like all Nehalem processors, I5 manages directly DDR3 memory in dual channel (unlike I7 wich use three). It support  DDR3 1066 and 1333 (the first models based on the I7 LGA1366 socket accept record that the 1066 or lower). Precisely the socket is since different passes LGA1156 (in conjunction with the series of eight I7: 860 and 870). The hyperthreading, located in the I7 is absent (or at least disable). By cons, he directly manages a port PCI-Express graphics card.

Despite the use of the old external bus DMI, the I5 finally takes the same architecture as its bigger brother. In this model, Intel gently remove the Intel northbridge incorporating a bus PCI-Express 2.0 directly into the processor (but more in the P55, the new chipset partner), which is not the case for the I7 9XX series, including Extreme Edition, which can manage via the P58 two-channel PCI-Express graphics). But the lack of PCI-Express dedicated to graphics cards in the P55 related to the I5 is important for players using either SLI NVIDIA or ATI CrossFire to couple up to three channels (for exemple  three cards screens simultaneous).

The cache sizes also remain same or L1 64 KB per core, 256 KB L2 cache (also by core) with 8 MB of L3 cache shared. A big difference anyway, the QPI does not serve as communication with the "northbridge" but only as internal liaison between hearts, the DMI is used external interface with still differences of 4.8 Giga Transfers per second (GT) for I7 to 2.5 GT / s for the I5. The DMI is used in latest Core2.

And Turbo mode? Already integrated in the other processors using this architecture, the turbo mode allows to increase the speed of each core above its rated speed temporarily as needed but remaining below the maximum consumption. For 3 or 4 cores depending on the increase is 133 MHz for all hearts. For 1 or 2 function, it allows an increase of 533 MHz on both. Inevitably, the Speedstep which reduces the speed in case of activity is also present, as well as Virtualization

Differents versions are currently proposed, I5 750 to 2.66 Mhz ofr first generation, and I5-2300 to I5-2500T for seconf generation including or not graphic card. Core I7 860 (2.8 MHz) and 870 (2.93 Mhz) use the same socket.

Other Intel microprocessors: Pentium - MMX - Pentium 2,  3 et 4 - Intel Core - 4004 (First processor in 1971);

Definitions Annexes: PCI-Express, caches L1, L2 and L3, Hyperthreading, the Speedstep, DMI bus - Virtualization - 32 / 64 bits