Opteron Totally Explained

Everything about The Opteron totally explained

The Opteron is AMD's x86 server processor line, and was the first processor to implement the AMD64 instruction set architecture (known generically as x86-64). It was released on April 22, 2003 with the SledgeHammer core (K8) and was intended to compete in the server market, particularly in the same segment as the Intel Xeon processor. Processors based on the AMD K10 microarchitecture (codenamed Barcelona) were announced on September 10, 2007 featuring a new quad-core configuration.

Technical description

The two key capabilities

Opteron combines two important capabilities in a single processor die:

native execution of legacy x86 32-bit applications without speed penalties
native execution of x86-64 64-bit applications

The first capability is notable because at the time of Opteron's introduction, the only other 64-bit processor architecture marketed with 32-bit x86 compatibility (Intel's Itanium) ran x86 legacy-applications only with significant speed degradation. The second capability, by itself, is less noteworthy, as all major RISC makers (Sun SPARC, DEC Alpha, HP PA-RISC, IBM POWER, SGI MIPS, etc.) have had 64-bit implementations for many years. In combining these two capabilities, however, the Opteron has earned recognition for its ability to run the vast installed base of x86 applications economically, while simultaneously offering an upgrade-path to 64-bit computing.
The Opteron processor possesses an integrated DDR SDRAM / DDR2 SDRAM (Socket AM2/F) memory controller. This both reduces the latency penalty for accessing the main RAM and eliminates the need for a separate northbridge chip.

Multi-processor features

In multi-processor systems (more than one Opteron on a single motherboard), the CPUs communicate using the Direct Connect Architecture over high-speed HyperTransport links. Each CPU can access the main memory of another processor, transparent to the programmer. The Opteron approach to multi-processing isn't the same as standard symmetric multiprocessing as instead of having one bank of memory for all CPUs, each CPU has its own memory. Thus the Opteron is a Non-Uniform Memory Access (NUMA) architecture. The Opteron CPU directly supports up to an 8-way configuration, which can be found in mid-level servers. Enterprise-level servers use additional (and expensive) routing chips to support more than 8 CPUs per box.
In a variety of computing benchmarks, the Opteron architecture has demonstrated better multi-processor scaling than the Intel Xeon. This is primarily because adding an additional Opteron processor increases bandwidth, while that isn't always the case for Xeon systems, and the fact that the Opterons use a switched fabric, rather than a shared bus. In particular, the Opteron's integrated memory controller allows the CPU to access local RAM very quickly. In contrast, multiprocessor Xeon system CPUs share only two common buses for both processor-processor and processor-memory communication. As the number of CPUs increases in a Xeon system, contention for the shared bus causes computing efficiency to drop.

Multi-core Opterons

In May of 2005, AMD introduced its first "Multi-Core" Opteron CPUs. At the present time, the term "Multi-Core" at AMD in practice means "dual-core"; each physical Opteron chip actually contains two separate processor cores. This effectively doubles the computing-power available to each motherboard processor socket. One socket can now deliver the performance of two processors, two sockets can deliver the performance of four processors, and so on. Since motherboard costs go up dramatically as the number of CPU sockets increases, multicore CPUs now allow much higher performing systems to be built with more affordable motherboards.
AMD's model number scheme has changed somewhat in light of its new multicore lineup. At the time of its introduction, AMD's fastest multicore Opteron was the model 875, with two cores running at 2.2 GHz each. AMD's fastest single-core Opteron at this time was the model 252, with one core running at 2.6 GHz. For multithreaded applications, the model 875 would be much faster than the model 252, but for single threaded applications the model 252 would perform faster. Next-Generation AMD Opteron processors

are offered in three series: the 1200 Series (up to 1P/2-core), the 2200 Series (up to 2P/4-core), and the 8200 Series (4P/8-core to 8P/16-core). The 1200 Series is built on AMD's new Socket AM2. The 2200 Series and 8200 Series are built on AMD's new Socket F.
AMD launched quad core Opteron chips on September 10th, 2007 with hardware vendors to follow suit with servers in the following month. Based on a core design codenamed Barcelona, new power and thermal management techniques are planned for the chips. Existing dual core DDR2 based platforms will be upgradeable to quad core chips.

Socket 939

AMD has also released Socket 939 Opterons, reducing the cost of motherboards for low-end servers and workstations. Except for the fact they've 1 MiB L2 Cache (versus 512 KiB for the Athlon64) the Socket 939 Opterons are identical to the San Diego and Toledo core Athlon 64s, but are run at lower clockspeeds than the cores are capable of, making them more stable. They are also the only dual core Socket 939 processors still easily available now that the Athlon 64 X2s for that platform have been discontinued, though even these processors are becoming more and more difficult to find. (External Link

)

Socket AM2

Socket AM2 Opterons are available for servers that only have a single-chip setup. These chips may prove to be as successful as the previous generation socket 939 Opterons due to the Opteron's overclockability. Codenamed Santa Ana, rev. F dual core AM2 Opterons feature 2×1 MiB L2 cache, unlike the majority of their Athlon 64 X2 cousins which feature 2x512 KiB L2 cache.

Socket F

Socket F (LGA 1207 contacts) is AMD’s second generation of Opteron socket. This socket support processors such as the Santa Rosa, Barcelona and Shanghai codenamed processors. The “Lidded Land Grid Array” socket adds support for DDR2 SDRAM and improved HyperTransport version 3 connectivity. Physically the socket and processor package are nearly identical, although not generally compatible with socket 1207 FX

Micro-architecture update

The Opteron line saw an update with the implementation of the AMD K10 microarchitecture. New processors, launched in the third quarter of 2007 (codename Barcelona), incorporate a variety of improvements, particularly in memory prefetching, speculative loads, SIMD execution and branch prediction, yielding an appreciable performance improvement over K8-based Opterons, within the same power envelope.
In the meantime, AMD has also utilized a new scheme to characterize the power consumption of new processors under "average" daily usage, named Average CPU Power (ACP).

Models

First generation single-core Opterons follow the three-digit "Opteron xyy" model numbers and going forward the newer generations (all dual cores) are four-digit in the form "Opteron xnyy".
The first digit (the x) specifies the maximum number of CPUs on the target machine:

1 - Designed for uniprocessor systems

2 - Designed for dual-processor systems

8 - Designed for systems with 4 or 8 processors The n digit is the release number (omitted in first release). The major differences between release one and release two include different socket type (socket 940 vs. socket F), single-core vs. dual core, quad-core upgradeability, support for DDR1 vs. DDR2 memory and for AMD Virtualization.
The last two digits in the model number (the yy) give an indication of the relative performance comparison among models of the processors.
Models with an HE label refers to a low-power deviative with 55W & 68W lower TDP value, while products with a SE label refers to a high performance processor with higher TDP values. A detailed list of Opteron microprocessors is here. The broad model families are:

Opteron (130 nm SOI)

Single-core — SledgeHammer (1yy, 2yy, 8yy)

CPU-Steppings: B3, 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

Registered DDR SDRAM required, ECC possible

VCore: 1.50 V - 1.55 V

Max Power (TDP): 89 W

First Release: April 22, 2003 (External Link

)

Clockrate: 1400–2400 MHz (x40 - x50)

Opteron (90 nm SOI, DDR)

Single-core — Venus (1yy), Troy (2yy), Athens (8yy)

CPU-Steppings: E4

L1-Cache: 64 + 64 KiB (Data + Instructions)

L2-Cache: 1024 KiB, fullspeed

MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64

Socket 940, 800 MHz HyperTransport

Socket 939/Socket 940, 1000 MHz HyperTransport

Registered DDR SDRAM required for socket 940, ECC possible

VCore: 1.35V - 1.4V

Max power (TDP): 95W

NX Bit

64-bit segment limit checks for VMware-style binary-translation virtualization.

Optimized Power Management (OPM)

First Release: February 14, 2005

Clockrate: 1600 - 3000 MHz (x42 - x56)

Dual-core — Denmark (1yy), Italy (2yy), Egypt (8yy)

CPU-Steppings: E1, E6

First Release: Spring 2005

Clockrate: 1600–2800 MHz (x60, x65, x70, x75, x80, x85, x90)

...

Socket 939/Socket 940, 1000 MHz HyperTransport

...

NX bit

Opteron (90 nm SOI, DDR2)

Dual-core — Santa Ana (12yy), Santa Rosa (22yy, 82yy)

CPU-Steppings: F2, F3

L1-Cache: 64 + 64 KiB (Data + Instructions)

L2-Cache: 2*1024 KiB, fullspeed

MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64

Socket F, ??? MHz HyperTransport - Opteron 2yy, 8yy

Socket AM2, ??? MHz HyperTransport - Opteron 1yy

VCore: 1.35 V

Max Power (TDP): 95W

NX Bit

AMD-V Virtualization

Optimized Power Management (OPM)

First Release: ?????? 2006

Clockrate: 1800–3200 MHz (xx10, xx12, xx14, xx16, xx18, xx20, xx20, xx22, xx24)

Opteron (65 nm SOI)

Quad-core — Barcelona (23yy, 83yy)

CPU-Steppings: BA

L1-Cache: 64 + 64 KiB (Data + Instructions) per core

L2-Cache: 512 KiB, fullspeed per core

L3-Cache: 2048 KiB, shared

MMX, Extended 3DNow!, SSE, SSE2, SSE3, AMD64, SSE4a

Socket F, Socket AM2+, HyperTransport 3.0 (1.6 GHz-2.0 GHz)

Registered DDR2 SDRAM required, ECC possible

VCore: ?

Max Power (TDP): ?

NX Bit

AMD-V Virtualization

Split power plane dynamic power management

VCore: 1.2 V

First Release: September 10, 2007

Clockrate: 1700–2000 MHz

Supercomputers

On the November 2007 TOP500 list, 15.8% of the world's 500 fastest known supercomputer installations were AMD64 Opteron-based systems (down from 22.6% on 11/06), while 64.4% were Intel ia32e/EM64T/Intel 64 Xeon-based.
Supercomputers based on Opteron mentioned in the top 10 fastest supercomputers in the world:

#6: Sandia National Laboratories, USA. Red Storm - Sandia/ Cray Red Storm, AMD64 Opteron Dual Core 2400 MHz. Cray Inc. 26,569 total cores. Rpeak: 127.531 TeraFlops.

#7: Oak Ridge National Laboratory, USA. Jaguar - Cray XT4/XT3. AMD64 Opteron Dual Core 2600 MHz (5.2 GFlops/unit). Cray Inc. 23,016 total cores. Rpeak: 119,350 TFlop.

#9: NERSC/LBNL, USA. Franklin - Cray XT4. AMD64 Opteron Dual Core 2600 MHz. Cray Inc. 19,320 total cores. Rpeak: 100,464 TFlop.

Issues

Opteron without Optimized Power Management

AMD has released some Opteron processors without Optimized Power Management(OPM) support, which use DDR memory. The following table describes those processors lacking OPM.

Max P-State Frequency	in P-State Frequency	Model	Package-Socket	Core #	Manufacturing Process	Part Number(OPN)
1400 MHz	N/A	140	Socket 940	1	130 nm	OSA140CEP5AT
1400 MHz	N/A	240	Socket 940	1	130 nm	OSA240CEP5AU
1400 MHz	N/A	840	Socket 940	1	130 nm	OSA840CEP5AV
1600 MHz	N/A	142	Socket 940	1	130 nm	OSA142CEP5AT
1600 MHz	N/A	242	Socket 940	1	130 nm	OSA242CEP5AU
1600 MHz	N/A	842	Socket 940	1	130 nm	OSA842CEP5AV
1600 MHz	N/A	242	Socket 940	1	90 nm	OSA242FAA5BL
1600 MHz	N/A	842	Socket 940	1	90 nm	OSA842FAA5BM
1600 MHz	N/A	260	Socket 940	2	90 nm	OSK260FAA6CB
1600 MHz	N/A	860	Socket 940	2	90 nm	OSK860FAA6CC

Opteron recall

AMD has recalled some E4 stepping-revision single-core Opteron processors, including x52 (2.6 GHz) and x54 (2.8 GHz) models which use DDR memory. The following table describes affected processors, as they're listed in AMD Opteron x52 and x54 Production Notice.

Max P-State Frequency	Uni-Processor	Dual Processor	Multi-Processor	Package-Socket
2600 MHz	152	252	852	Socket 940
2800 MHz	N/A	254	854	Socket 940
2600 MHz	152	N/A	N/A	Socket 939
2800 MHz	154	N/A	N/A	Socket 939

The affected processors may produce inconsistent results in the presence of three specific conditions occurring simultaneously:

The execution of floating point-intensive code sequences

Elevated processor temperatures

Elevated ambient temperatures A software verification tool for identifying the AMD Opteron processors listed in the above table that may be affected under these specific conditions is available only to AMD OEM partners. AMD will replace those processors at no charge.

Future

Future Opteron processors will see an implementation of the Montreal core based on a 45 nm fabrication node, manufactured using the MCM technique. Further, the server line of processors will incorporate the newly announced Bulldozer core with native 4 cores or more configurations, each supporting SSE5 aimed at better HPC and cryptographic computations.

Further Information

Get more info on 'Opteron'.

External Link Exchanges

Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:

<a href="http://opteron.totallyexplained.com">Opteron Totally Explained</a>

Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned.