AMD Opteron 842

AMD Opteron 842 is a single-core server processor from the K8 architecture family, codenamed Athens, running at a base clock of 1600 MHz. It sits at the 50th percentile among all CPUs in the benchmark database, indicating a median position in historical performance distribution. The chip targets the Server/Workstation market segment and is now end-of-life, having been released on November 30, 2004.

Single-Thread vs Multi-Thread Behavior

The Opteron 842 contains exactly one core and one thread, meaning all computational work is serialized through a single execution pipeline. This design makes single-thread performance the only relevant metric; there is no multi-thread scaling to analyze because the processor cannot execute parallel workloads natively. For any application that relies on concurrent execution, the Opteron 842 will be severely constrained, it processes one instruction stream at a time, regardless of how many tasks the operating system schedules.

The base clock of 1600 MHz is modest even for its era, and with no boost clock available, the processor operates at a fixed frequency under all conditions. This flat clock behavior means performance is predictable but never dynamically enhanced. The absence of a boost clock also implies that burst workloads cannot receive a temporary frequency bump, so latency-sensitive tasks have no headroom beyond the static 1600 MHz rate.

Given the single-thread nature, the Opteron 842 is best suited for legacy applications that were written for single-processor execution, such as certain database transactions or serialized scientific calculations. However, modern operating systems and applications increasingly expect multi-threading, so the lack of additional cores or threads limits the processor to very specific, specialized use cases. The 50th percentile ranking suggests it sits exactly in the middle of historical CPU performance, which aligns with a mid-tier single-core server part from its generation.

Power and Thermals

The thermal design power (TDP) is rated at 85 watts, which places the Opteron 842 in a moderate power class for a server processor. For a single-core chip running at 1600 MHz, an 85W TDP indicates a relatively power-hungry design per core, likely due to the 90 nm process node and the K8 architecture's electrical characteristics. The 90 nm manufacturing process, using 106 million transistors, contributes to this power draw, smaller process nodes typically reduce power, but 90 nm was not exceptionally dense by modern standards.

The 85W TDP implies that a standard server heat sink with adequate airflow should suffice, no exotic cooling solution is required. The absence of a boost clock means power consumption stays relatively constant under sustained load, as there are no frequency spikes that would cause thermal transients. This predictability is advantageous for data center environments where thermal management is critical.

Since the processor is end-of-life and uses the AMD Socket 940 platform, cooling solutions must match that specific socket retention mechanism. The 85W rating is moderate enough that passive cooling or low-profile active coolers could be considered, but the server form factor typically demands active cooling for reliability. The data does not specify any thermal throttling behavior, so sustained operation at 1600 MHz is assumed under the rated TDP.

Benchmark Performance

The average benchmark score for the Opteron 842 is 0, and the percentile rank is 50, which suggests the processor has either not been widely benchmarked or its scores were not recorded in the database. The nearest rivals list is empty, meaning there are no direct comparison points from the database that share its performance envelope. This absence of comparative data limits the ability to state exact percentage deltas against competing processors.

However, the 50th percentile position provides context: the Opteron 842 performs better than half of all CPUs ever cataloged, and worse than the other half. Given its single-core, 1600 MHz configuration, this median ranking likely reflects a processor that was competitive in its server niche during its lifetime but has been surpassed by subsequent generations. The single-thread nature means its benchmark scores, if available, would reflect raw IPC and clock speed, but with no recorded scores, only the percentile is usable.

The lack of nearest rivals means the Opteron 842 occupies a unique position in the database, no other processor is statistically close enough to warrant a comparison entry. This could indicate that its performance profile is either too old or too specialized to match modern parts. Without benchmark scores, the practical interpretation is that the processor delivers baseline server functionality, with the median percentile confirming it was neither a high-end nor a low-end part in its time.

Platform and Compatibility

The Opteron 842 uses the AMD Socket 940 platform, which is a server-oriented socket that supports registered memory. Memory support is dual-channel, though the specific type and capacity are not specified in the data. ECC memory is not supported, which is unusual for a server processor, this limits its use in environments where data integrity is critical, such as financial transactions or scientific computing that relies on error detection.

PCIe generation is Gen 2, which provides adequate bandwidth for expansion cards from that era, such as network controllers or storage adapters. The socket is specific to the Opteron Athens generation, so upgrade paths are limited to other Socket 940 processors from the same family. Since the production status is end-of-life, obtaining replacement or upgrade chips is dependent on secondary markets.

The processor has a fixed multiplier and is not unlocked, so overclocking is not possible. The part number is OSA842FAA5BM, which helps identify compatibility with specific motherboards. The K8 architecture and 90 nm process node are legacy technologies, so modern motherboards with newer sockets will not accept this chip. The memory bus being dual-channel suggests a two-DIMM configuration for optimal bandwidth, though no memory bandwidth figure is provided.

How It Compares

The nearest rivals list is empty, so the Opteron 842 has no direct comparisons in the benchmark database. This means its performance cannot be expressed relative to specific competing processors with exact percentage deltas. The 50th percentile is the only positional reference, indicating an average historical standing.

In the absence of rival data, the comparison must rely on architectural context. The single-core K8 design places it below multi-core contemporaries in any parallel workload. For single-threaded applications, the 1600 MHz clock is roughly comparable to other early 2000s server chips, but without specific rival scores, no quantitative comparison is possible.

The empty nearestRivals field also suggests that the benchmark database does not consider any other processor statistically similar to the Opteron 842. This could be because its benchmark scores are zero or missing, precluding meaningful comparative statistics. Therefore, the processor stands alone in the dataset, and any performance positioning must be inferred from its core count, clock speed, and percentile.

FAQ

Q: How many cores does the AMD Opteron 842 have?

A: The processor has exactly one core and one thread, making it a single-threaded CPU.

Q: What is the base clock speed of the Opteron 842?

A: The base clock is 1600 MHz, and there is no boost clock available.

Q: Does the Opteron 842 support ECC memory?

A: No, ECC memory is not supported, which is notable for a server processor.

Q: What socket does the Opteron 842 use?

A: It uses the AMD Socket 940 platform, which is specific to the K8 Athens generation.

Q: What is the TDP of the Opteron 842?

A: The thermal design power is rated at 85 watts.

Q: Is the Opteron 842 still in production?

A: The production status is end-of-life, and it was released on November 30, 2004.

Who Should Consider It

The Opteron 842 is appropriate for environments that run legacy single-threaded server applications where multi-core scaling is not a requirement. Given its single-core design and 1600 MHz clock, it is not suitable for modern gaming, which typically demands at least four cores and higher frequencies. The 50th percentile ranking confirms it is an average performer historically, but that average is based on a single thread.

For office productivity tasks, the processor would struggle with modern multitasking, as the single thread must handle the operating system, applications, and background processes simultaneously. The lack of ECC memory further disqualifies it from reliability-critical workloads. However, for embedded or dedicated control systems that run one fixed program, the Opteron 842 could still function, provided the software is compatible with the Socket 940 platform and the K8 instruction set.

Server/workstation use cases that involve serialized computations, such as certain financial models or single-threaded database queries, might find the Opteron 842 acceptable if the workload is light. The 85W TDP allows for compact cooling, and the dual-channel memory bus offers adequate bandwidth for basic server tasks. Yet, any modern workload that benefits from multiple threads would be better served by a different processor, as the Opteron 842 cannot parallelize work at all.