DDR2

The Athlon 64 had been maligned by some critics for some time because of its lack of support for DDR2 SDRAM, an emerging technology that had been adopted much earlier by Intel. AMD's official position was that the CAS latency on DDR2 had not progressed to a point where it would be advantageous for the consumer to adopt it. AMD finally remedied this gap with the "Orleans" core revision, the first Athlon 64 to fit Socket AM2, released on on May 23, 2006. "Windsor", an Athlon 64 X2 revision for Socket AM2, was released concurrently. Both Orleans and Windsor have 1 MiB of L2 cache per core. The Athlon 64 FX-62 was also released concurrently on the Socket AM2 platform. Socket AM2 also consumes less power than previous platforms, and also supports AMD's virtualization technology.

Features

There are four variants: Athlon 64, Athlon 64 FX, Mobile Athlon 64 (later renamed "Turion 64") and the dual-core Athlon 64 X2. Common among the Athlon 64 line are a variety of instruction sets including MMX, SSE, SSE2, 3DNow!, and AMD64. All Athlon 64s with the exception of the original ClawHammer release also support the NX bit, a security feature named "Enhanced Virus Protection" by AMD. And as implementations of the AMD64 architecture, all Athlon 64 variants are able to run 16 bit, 32 bit x86, and AMD64 code, through two different modes the processor can run in: "Legacy mode" and "long mode". Legacy mode runs 16-bit and 32-bit programs natively, and long mode runs 64-bit programs natively, but also allows for 32-bit programs running inside a 64-bit operating system. All Athlon 64 processors feature 128 kibibytes of level 1 cache, and at least 512 kibibytes of level 2 cache.

The Athlon 64 features an on-die memory controller, a feature not previously seen on x86 CPUs. Not only does this mean the controller runs at the same clock rate as the CPU itself, it also means the electrical signals have a shorter physical distance to travel compared to the old northbridge interfaces. The result is a significant reduction in latency (response time) for access requests to main memory. The lower latency is often cited as one of the advantages of the Athlon 64's architecture over those of its competitors.

Translation Lookaside Buffers (TLBs) have also been enlarged (40 4k/2M/4M entries in L1 cache, 512 4k entries), with reduced latencies and improved branch prediction, with four times the number of bimodal counters in the global history counter. This and other architectural enhancements, especially as regards SSE implementation, improve instruction per cycle (IPC) performance over the previous Athlon XP generation. To make this easier for consumers to understand, AMD has chosen to market the Athlon 64 using a PR rating (Performance Rating) system, where the numbers roughly map to Pentium 4 performance equivalents, rather than actual clock speed.

Athlon 64 also features CPU speed throttling technology branded Cool'n'Quiet, a feature similar to Intel's SpeedStep that can throttle the processor's clock speed back to facilitate lower power consumption and heat production. When the user is running undemanding applications and the load on the processor is light, the processor's clock speed and voltage are reduced. This in turn reduces its peak power consumption (max TDP set at 89 W by AMD) to as low as 32 W (stepping C0, clock speed reduced to 800 MHz) or 22W (stepping CG, clock speed reduced to 1 GHz). The Athlon 64 also has an Integrated Heat Spreader (IHS) which prevents the CPU core from accidentally being damaged when mounting and unmounting cooling solutions. With prior AMD CPUs a CPU shim could be used by people worried about damaging the core.

The No Execute bit (NX bit) supported by Windows XP Service Pack 2, Windows XP Professional x64 Edition, Windows Server 2003 x64 Edition, and Linux 2.6.8 and higher is also included, for improved protection from malicious buffer overflow security threats. Hardware-set permission levels make it much more difficult for malicious code to take control of the system. It is intended to make 64-bit computing a more secure environment.

The Athlon 64 CPUs have been produced with 130 nm and 90 nm SOI process technologies. All of the latest chips (Winchester, Venice and San Diego models) are on 90 nm. The Venice and San Diego models also incorporate dual stress liner technology (an amalgam of strained silicon and 'squeezed silicon', the latter of which is not actually a technology) co-developed with IBM.

As the memory controller is integrated onto the CPU die, there is no FSB for the system memory to base its speed upon. Instead, system memory speed is obtained by using the following formula (using the ceiling function):

$\backslash frac\{CPU\; speed\}\{\backslash lceil\backslash frac\{CPU\; multiplier\}\{DRAM\; divider\}\backslash rceil\}=DRAM\; speed$

In simpler terms, the memory is always running at a set fraction of the CPU speed, with the divisor being a whole number. An 'FSB' figure is still used to determine the CPU speed, but the RAM speed is no longer directly related to this 'FSB' figure (known otherwise as the LDT).

Athlon 64 FX

Athlon 64 X2

Main article: Athlon 64 X2

Mobile Athlon 64

Main article: Turion 64

Sockets

• 754: The Athlon 64 value/budget line, 64-bit memory interface (Single-Channel)
• 939: Athlon 64 performance line, Athlon 64 X2s, and newer Athlon 64 FXs, 128-bit memory interface (Dual-channel)
• 940: Opteron and old Athlon 64 FX, 128-bit memory interface - requires registered DDR memory
• Socket F: Opteron. Yet to be Released (ETA 2006), 1207 Pins
• Socket AM2: Athlon 64/Athlon 64 FX/Athlon 64 X2/Sempron Will replace Sockets 754 and 939 in 2006. 940 Pins (Not compatible with Socket 940) and will be the first AMD socket to use DDR2 SDRAM.

At the introduction of Athlon 64 in September 2003, only Socket 754 and Socket 940 (Opteron) were ready and available. The onboard memory controller was not capable of running unbuffered (non-registered) memory in dual-channel mode at the time of release; as a stopgap measure, they introduced the Athlon 64 on Socket 754, and brought out a non-multiprocessor version of the Opteron called the Athlon 64 FX, as a multiplier unlocked enthusiast part for Socket 940, comparable to Intel's Pentium 4 Extreme Edition for the high end market.

In June 2004, AMD released Socket 939 as the mainstream Athlon 64 with dual-channel memory interface, leaving Socket 940 solely for the server market (Opterons), and relegating Socket 754 as a value/budget line, for Semprons and slower versions of the Athlon 64. Eventually Socket 754 replaced Socket A for Semprons.

Athlon 64 FX models

Sledgehammer (130 nm SOI)

• CPU-Stepping: C0, CG
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 1024 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, AMD64
• Socket 940, 800 MHz HyperTransport (HT800)
• Registered DDR-SDRAM required
• VCore: 1.50/1.55 V
• Power Consumption (TDP): 89 Watt max
• First Release: September 23, 2003
• Clockrate: 2200 MHz (FX-51, C0), 2400 MHz (FX-53, C0 and CG)

Clawhammer (130 nm SOI)

• CPU-Stepping: CG
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 1024 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, AMD64
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.50 V
• Power Consumption (TDP): 89 Watt (FX-55:104 Watt)
• First Release: June 1, 2004
• Clockrate: 2400 MHz (FX-53), 2600 MHz (FX-55)

San Diego (90 nm SOI)

• CPU-Stepping: E4, E6
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 1024 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, Cool'n'Quiet, NX Bit
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.35 V or 1.40 V
• Power Consumption (TDP): 104 Watt max
• First Release: April 15, 2005
• Clockrate: 2600 MHz (FX-55), 2800 MHz (FX-57)

Toledo (90 nm SOI)

• CPU-Stepping: E6
• L1-Cache: 64 + 64 KiB (Data + Instructions), per core
• L2-Cache: 1024 KiB fullspeed, per core
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, Cool'n'Quiet, NX Bit
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.30 V - 1.35 V
• Power Consumption (TDP): 110 Watt max
• First Release: January 10, 2006
• Clockrate: 2600 MHz (FX-60)

Windsor (90 nm SOI)

• CPU-Stepping: F2
• L1-Cache: 64 + 64 KiB (Data + Instructions), per core
• L2-Cache: 1024 KiB fullspeed, per core
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, Cool'n'Quiet, NX Bit, AMD Virtualization
• Socket AM2, 1000 MHz HyperTransport (HT1000)
• VCore: 1.30 V - 1.35 V
• Power Consumption (TDP): 125 Watt max
• First Release: May 23, 2006
• Clockrate: 2800 MHz (FX-62)

Athlon 64 models

ClawHammer (130 nm SOI)

• CPU-Stepping: C0, CG
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 1024 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, AMD64, Cool'n'Quiet, NX Bit (only CG)
• Socket 754, 800 MHz HyperTransport (HT800)
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.50 V
• Power Consumption (TDP): 89 Watt max
• First Release: September 23, 2003
• Clockrate: 2000 - 2600 MHz

Newcastle (130 nm SOI)

• CPU-Stepping: CG
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 512 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, AMD64, Cool'n'Quiet, NX Bit
• Socket 754, 800 MHz HyperTransport (HT800)
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.50 V
• Power Consumption (TDP): 89 Watt max
• First Release: 2004
• Clockrate: 1800 - 2400 MHz

Winchester (90 nm SOI)

• CPU-Stepping: D0
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 512 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, AMD64, Cool'n'Quiet, NX Bit
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.40 V
• Power Consumption (TDP): 67 Watt max
• First Release: 2004
• Clockrate: 1800 - 2200 MHz

Venice (90 nm SOI)

• CPU-Stepping: E3, E6
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 512 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, Cool'n'Quiet, NX Bit
• Socket 754, 800 MHz HyperTransport (HT800)
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.35 V or 1.40 V
• Power Consumption (TDP): 67 Watt max
• First Release: April 4, 2005
• Clockrate: 1800 - 2400 MHz

San Diego (90 nm SOI)

• CPU-Stepping: E4, E6
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 1024 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, Cool'n'Quiet, NX Bit
• Socket 939, 1000 MHz HyperTransport (HT1000)
• VCore: 1.35 V or 1.40 V
• Power Consumption (TDP): 89 Watt max
• First Release: April 15, 2005
• Clockrate: 2200 - 2800 MHz

Orleans (90 nm SOI)

• CPU-Stepping: F2
• L1-Cache: 64 + 64 KiB (Data + Instructions)
• L2-Cache: 512 KiB, fullspeed
• MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, Cool'n'Quiet, NX Bit
• Socket AM2, 1000 MHz HyperTransport (HT1000)
• VCore: 1.35 V or 1.40 V
• Power Consumption (TDP): 62 Watt max
• First Release: May 23, 2006
• Clockrate: 2000 - 2400 MHz

See also

• List of AMD Athlon 64 microprocessors

References

External links

• Facts & Assumptions about the Architecture of AMD Opteron and Athlon 64
• Understanding the detailed Architecture of AMD's 64 bit Core
• Inside AMD's Hammer: the 64-bit architecture behind the Opteron and Athlon 64
• Tom's Hardware Guide and the AMD 64
• Linux on laptops with 64bit CPU
• Detailed description of the K8 core
• xBitLabs article about AMD's move to 90nm
• Athlon 64 for Quiet Power
• AMD Athlon 64 technical specifications
• AMD64/Opteron Model Number Decoder

AMD products | x86 microprocessors

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