Monday, April 27, 2009

AMD Phenom X4 II 955: DDR3 and up-market

AMD resurfaced about him at the end of April with the launch of the Phenom X4 II 955, its new quad-core processor. Falling in line with recent Phenom II processors, the newcomer is distinguished by an operating frequency slightly higher and the use of socket AM3, which involves the use of DDR3 memory.

Recall that earlier this year, AMD Phenom renew its offer with the release of Phenom second name engraved in 45 nm. While the first Phenom line was recently received, because many technical problems, Phenom II has managed to establish itself as a credible alternative to Intel's offering at least on the entry slot and mid-range. And while the Phenom X4 II 940 we had left a good memory, AMD declined a bit over its offer with the release of AM3 models employing DDR3 memory: it was in mid-February.

A few months later, AMD is back then, with not one but two new processors Phenom X4 II completing the series 900. These II X4 Phenom 945 and Phenom X4 II 955 Black Edition, both with integrated DDR3 memory controller. Overview of newcomers.

AMD Phenom X4 II: Background on the socket AM3

Brand new, still recent, the AM3 socket follows the socket AM2 and AM2 + used by the latest AMD processors. Unlike the previous account AM3 socket 938 pin when he offers no compatibility. In short, no point in installing a processor on the AM2 + socket AM3. But the reverse is not true! A processor socket AM3, the Phenom X4 955 II before us today, can be installed on a motherboard with socket AM2 +.

Technically processors AM2 and AM2 + integrate a DDR2 memory controller and DDR2 only. That is why they can not work on AM3 infrastructure that requires the use of DDR3 memory. In contrast, AM3 processors include a memory controller capable of operating both with DDR2 memory as with DDR3.

AMD Phenom X4 II: Reminders on DDR3 memory

Like the Phenom X4 II 810, previously tested in our columns (see AMD Socket AM3 Phenom II: forward DDR3!), The Phenom X4 II is 955, you will understood by its DDR3 memory controller. For stunned, note that since the release of Athlon 64 processors, which correspond to the K8 architecture, AMD integrates the memory controller directly into the processor. This role is no longer vested in the chipset of the motherboard ... that Intel has a choice to embrace with its recent Core i7 processors with Nehalem architecture. The advantage, at least on paper, is to reduce the latency which can sometimes improve performance.

Faster than DDR2, DDR3 memory effect allows the operating frequency while higher bandwidth chip is twice as high at the same frequency, as the DDR2. The consideration is latency times significantly more important, though less than what we could fear. Using a supply voltage lower, DDR3 memory is expected to consume less than DDR2: formal specification refers to a supply voltage of 1.5 volts. In practice, DDR3 memory modules still require a voltage of 1.7 or 1.8 volt. As for technical specifications, II Phenom processors, both as AM3, all benefit from a memory controller capable of supporting the DDR3 1333.

It should be noted in passing strategic inflection AMD now leaving the task to Intel to try to care of new memory technologies before adopting them in turn. This was the case with DDR2, first proposed by Intel with its Intel chipsets i9x5, but also appeared with the DDR3 with the P35 chipset family. In short, AMD gives Intel wipe casts to enjoy by following a more mature technology.

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