AMD Opteron 6238

AMD Opteron 6238 is a 12-core, 12-thread server processor built on the Bulldozer architecture with a 32 nm process, released in November 2011. It operates at a base clock of 2.60 GHz and a boost clock of 3.20 GHz, with a TDP of 115 W. The chip targets the server and workstation segment, featuring quad-channel DDR3 memory support with 51.2 GB/s bandwidth and 768 KB of L1 cache, 2 MB per module of L2 cache, and 8 MB per die of L3 cache.

Benchmark Performance

The Opteron 6238’s multi-core scores establish it as a solidly mid-range performer. In Cinebench R15 multi-core, it scores 481 points, while R20 multi-core yields 2008 points, and R23 multi-core reaches 4781 points. These numbers place the processor at the 37th percentile among all CPUs, indicating it outperforms roughly a third of the database’s tracked processors. The average benchmark score across all tests is 1383, which aligns closely with its nearest rivals, all of which sit within a 0.3% delta of this figure.

Single-core performance tells a more modest story. The chip scores 67 points in Cinebench R15 single-core, 283 in R20 single-core, and 675 in R23 single-core. These figures are dramatically lower than the multi-core results, reflecting the inherent design limitations of the Bulldozer architecture for lightly-threaded workloads. The single-core scores are approximately 7% of the multi-core scores in each Cinebench version, illustrating that the processor’s strength lies entirely in parallel throughput rather than per-thread efficiency.

The deltaPct values against nearest rivals are remarkably tight. The Opteron 6238’s average score of 1383 is just 0.1% higher than the Intel Core i7-3615QE’s 1381, 0.2% higher than the Intel Core i7-2600K’s 1380, and 0.3% higher than the AMD Opteron 6366 HE’s 1379. Conversely, it trails the AMD Opteron 6274’s 1387 by 0.3%. These sub-1% margins mean the processor is effectively tied with all four rivals in aggregate performance, making benchmark run-to-run variance more significant than any actual performance gap.

How It Compares

Against the Intel Core i7-3615QE, the Opteron 6238 shows a negligible 0.1% average score advantage. The i7-3615QE is a mobile-class quad-core part, yet its higher single-thread efficiency nearly offsets the Opteron’s 12-core count in mixed workloads. In practice, the Opteron will pull ahead in heavily parallel tasks, but the Intel chip counters with superior responsiveness in single-threaded applications.

The comparison with the Intel Core i7-2600K is similarly close, with the Opteron leading by just 0.2% on average. The i7-2600K is a desktop quad-core with eight threads and a much higher clock speed, yet the aggregate scores are essentially identical. This highlights how the Opteron’s raw core count compensates for its lower per-core performance, but the Intel chip remains the better choice for latency-sensitive or lightly-threaded workloads.

Versus the AMD Opteron 6366 HE, the 6238 holds a 0.3% average score edge. The 6366 HE is a lower-power variant from the same Interlagos family, so the performance difference is minimal despite the 6238’s higher TDP. Both chips share the same architectural strengths and weaknesses, making them nearly interchangeable in server deployments.

The AMD Opteron 6274 is the only rival to surpass the 6238, doing so by 0.3% on average. The 6274 is also a 16-core part, giving it two additional modules compared to the 6238’s 12 cores. Despite this core-count disadvantage, the 6238 stays within striking distance, demonstrating that the 6274’s extra cores translate to only a marginal aggregate improvement.

Power and Thermals

The Opteron 6238 carries a TDP rating of 115 W, placing it in the mainstream server processor power class. This figure is moderate for a 12-core Bulldozer part, which historically consumed more power per core than competing Intel designs. The 115 W TDP implies that a capable air cooler or a low-end server heatsink is sufficient to maintain safe operating temperatures under sustained load.

Given the 32 nm process node from GlobalFoundries and the dual-die design with 2x 315 mm² die size, thermal density is a consideration. The processor’s 2,400 million transistors are spread across two dies, which helps distribute heat but also means two separate hotspots. Server chassis with proper front-to-back airflow will handle this chip without issue, but dense blade enclosures may require additional attention to cooling.

The 115 W TDP also suggests that the processor can be deployed in dual-socket configurations without exceeding typical power budgets for 2U or 4U servers. Power efficiency is not a standout trait, as the Bulldozer architecture was not known for performance-per-watt leadership, but the TDP is within the expected range for a 2011-era server chip. The Opteron 6366 HE, a rival with a lower power envelope, achieves nearly identical performance, indicating that the 6238 is not optimized for energy-sensitive environments.

Who Should Consider It

The Opteron 6238 is best suited for workloads that scale with core count and tolerate lower single-thread performance. In multi-threaded rendering tasks, the Cinebench R23 multi-core score of 4781 positions it as a capable processor for batch rendering of still frames or offline video encoding, where parallel throughput is the primary metric. The R20 multi-core score of 2008 further confirms this, showing consistent scaling across different rendering benchmarks.

For database servers or virtualization hosts running many concurrent lightweight threads, the 12 cores provide ample parallelism. The quad-channel memory bus with 51.2 GB/s bandwidth supports multiple simultaneous memory-intensive operations, and ECC memory support makes it suitable for reliability-critical applications. The server market segment designation aligns with these use cases, where single-thread performance is secondary to total throughput.

The processor is a poor fit for gaming or interactive workstation use. The single-core score of 675 in Cinebench R23 is roughly one-seventh of the multi-core score, meaning any workload with a dominant serial component will bottleneck severely. Office productivity applications, web browsing, and even light photo editing will feel sluggish compared to modern desktop chips, despite the 12-core count. The chip’s end-of-life production status and 2011 release date further limit its appeal for new deployments.

Single-Thread vs Multi-Thread Behavior

The Opteron 6238 exhibits an extreme divergence between single-thread and multi-thread performance. In Cinebench R15, the single-core score of 67 is only 13.9% of the multi-core score of 481. This ratio persists in R20, where 283 single-core is 14.1% of 2008 multi-core, and in R23, where 675 single-core is 14.1% of 4781 multi-core. These consistent ratios indicate that the processor’s multi-core scaling is nearly perfect, with all 12 cores contributing roughly equally to parallel workloads.

The architectural reason lies in the Bulldozer design, which pairs two integer cores per module but shares floating-point units and cache resources. This design choice prioritizes throughput over latency, making the chip excel at embarrassingly parallel tasks while struggling with anything requiring fast sequential execution. The boost clock of 3.20 GHz cannot compensate for the low instructions-per-clock of the Bulldozer microarchitecture in single-threaded code.

Real-world implications are clear: workloads like video transcoding, 3D scene rendering, and scientific simulations with high thread counts will see near-linear scaling across all 12 cores. Conversely, tasks like spreadsheet calculations, script execution, or single-threaded legacy applications will perform at a level comparable to low-end dual-core processors from the same era. The 37th percentile overall ranking reflects this split, as the aggregate score averages strong multi-core results with weak single-core results. Buyers must therefore evaluate their specific workload mix carefully, as the Opteron 6238 is a specialist tool for parallel processing rather than a general-purpose processor.