CPU Comparison

The Intel Pentium 6805 and the Intel Xeon E5-1603 v3 are separated by six years of architecture, yet their benchmark scores are nearly indistinguishable. The data reveals a fascinating convergence: a 15-watt mobile chip from 2020 matches a 140-watt server/workstation processor from 2014 in every single Cinebench test, with average scores of 1099 and 1098 respectively. This begs the question of whether raw core count and memory bandwidth matter when single-threaded performance and IPC improvements have advanced so far.

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Pentium 6805 edges out the Xeon E5-1603 v3 by a single point, scoring 1099 compared to 1098. Both processors sit at the 31st percentile of all CPUs tracked in the database.

Q: How do the two chips compare in multi-core Cinebench R23?

A: The Pentium 6805 scores 3801, which is 0.1% higher than the Xeon's 3798. This is a margin of just three points, effectively a tie in real-world terms.

Q: Is there any benchmark where the Xeon E5-1603 v3 wins?

A: No. According to the head-to-head data, the Pentium 6805 wins all six benchmark comparisons, though four of those wins are by 0% or 0.1% margins. The Xeon's largest deficit is 0.3% in Cinebench R15 multi-core.

Q: What are the core and thread counts of each processor?

A: The Pentium 6805 has 2 cores and 4 threads, while the Xeon E5-1603 v3 has 4 cores and 4 threads. Despite having half the physical cores, the Pentium's hyper-threading allows it to match the Xeon's thread count.

Q: Do both processors support ECC memory?

A: No. The Xeon E5-1603 v3 supports ECC memory, while the Pentium 6805 does not. This is a critical differentiator for workstation reliability use cases.

Q: What is the TDP difference between the two?

A: The Pentium 6805 has a TDP of 15 watts, while the Xeon E5-1603 v3 has a TDP of 140 watts. This is a substantial difference in power consumption and thermal output.

Architecture Differences

The Pentium 6805 is built on Intel's 10 nm process node using the Ice Lake-Y architecture, codenamed Sunny Cove-Y. It sports a die size of 123 mm², a relatively compact design for a mobile-focused chip. In contrast, the Xeon E5-1603 v3 uses the older 22 nm Haswell-EP architecture, with a substantially larger die size of 356 mm² and a transistor count of 2,600 million. The process node difference alone suggests the Pentium should have a significant efficiency advantage, which is borne out by the TDP figures.

The cache hierarchies tell a different story. The Pentium 6805 has 80 KB of L1 cache per core and 256 KB of L2 per core, but only 4 MB of shared L3 cache. The Xeon E5-1603 v3 has 64 KB of L1 per core, the same 256 KB of L2 per core, but a much larger 10 MB of shared L3 cache. This 2.5x difference in L3 cache could theoretically benefit the Xeon in workloads with large working sets, yet the benchmark data does not reflect any such advantage.

Memory support also diverges significantly. Both support DDR4, but the Pentium uses a dual-channel memory bus with 51.2 GB/s of bandwidth, while the Xeon uses a quad-channel bus with 59.7 GB/s. The Xeon also offers ECC memory support and 40 PCIe Gen 3 lanes from the CPU, whereas the Pentium has integrated UHD Graphics (32EU) and no ECC. The Pentium's integrated graphics is a notable feature absent from the Xeon, which has none.

Head-to-Head Benchmarks

The benchmark results are remarkably close across all six Cinebench tests. In Cinebench R15 multi-core, the Pentium 6805 scores 383 versus the Xeon's 382, a 0.3% difference that represents the largest gap in any test. This is surprising given that the Xeon has twice the physical cores, suggesting that the Pentium's higher clock speed and newer architecture compensate for its core deficit.

Single-core performance is essentially identical. In Cinebench R15 single-core, both score 54; in R20 single-core, both score 225; and in R23 single-core, both score 536. The Pentium's base clock is listed as 1100 MHz with a boost clock of 3.00 GHz, while the Xeon has a fixed base clock of 2.80 GHz with no boost capability. This clock speed advantage for the Pentium appears to neutralize any architectural edge the Xeon might have had from its larger cache.

Multi-core results follow the same pattern. The Pentium scores 1596 in R20 multi-core versus 1595 for the Xeon, and 3801 versus 3798 in R23 multi-core. These differences of 0.1% are within measurement noise, indicating that the two processors deliver effectively identical multi-threaded performance despite their vastly different hardware configurations. The data suggests that the Pentium's 4 threads are sufficient to match the Xeon's 4 threads when combined with superior per-core efficiency.

Specification Differences

The two processors differ in nearly every major specification category. The Pentium 6805 has 2 cores and 4 threads, while the Xeon E5-1603 v3 has 4 cores and 4 threads. Base clocks are 1100 MHz for the Pentium and 2.80 GHz for the Xeon, but the Pentium offers a boost clock of 3.00 GHz while the Xeon has none. TDP is a dramatic 15 watts versus 140 watts.

The sockets are incompatible: the Pentium uses Intel BGA 1526, while the Xeon uses Intel Socket 2011-3. Process nodes are 10 nm versus 22 nm, and die sizes are 123 mm² versus 356 mm². The Xeon has a specified transistor count of 2,600 million, while the Pentium's is not listed. Cache configurations differ in L1 (80 KB per core versus 64 KB per core) and L3 (4 MB shared versus 10 MB shared), but match on L2 at 256 KB per core.

Memory channels are dual-channel versus quad-channel, with bandwidth of 51.2 GB/s versus 59.7 GB/s. ECC support is absent on the Pentium and present on the Xeon. The Pentium includes integrated UHD Graphics (32EU); the Xeon has none. Market segments are Mobile versus Server/Workstation. The Pentium has a launch MSRP of $161; the Xeon has no listed launch MSRP. Release dates are September 2020 versus September 2014.

The Verdict

The benchmark data makes a compelling case that the Pentium 6805 is the superior processor for most users. It matches the Xeon E5-1603 v3 in every single-threaded and multi-threaded Cinebench test while consuming only 15 watts versus 140 watts, making it dramatically more power-efficient. The Pentium also includes integrated graphics, which the Xeon lacks entirely, and uses a modern 10 nm process compared to the Xeon's 22 nm.

However, the Xeon holds advantages in specific areas that matter for certain workloads. Its quad-channel memory bus provides higher bandwidth at 59.7 GB/s versus 51.2 GB/s, and its ECC memory support is critical for data integrity in server environments. The larger 10 MB L3 cache could theoretically benefit cache-sensitive applications, though the benchmarks do not demonstrate this advantage. The Xeon also offers 40 PCIe Gen 3 lanes from the CPU, which is important for workstation expansion.

For a general-purpose or mobile computing scenario, the Pentium 6805 is the clear choice based on its efficiency, integrated graphics, and identical benchmark performance. For a server or workstation requiring ECC memory and maximum memory bandwidth, the Xeon E5-1603 v3 has the necessary features despite its age and higher power draw.

Where Each One Wins

The Pentium 6805 wins in every measured benchmark category, but its real victories are in efficiency and feature integration. The 15-watt TDP makes it suitable for fanless or passively cooled designs, while the integrated UHD Graphics eliminates the need for a discrete GPU in basic display tasks. Its modern 10 nm process and boost clock of 3.00 GHz deliver performance that belies its low base clock of 1100 MHz. The launch MSRP of $161 positions it as a cost-effective mobile solution.

The Xeon E5-1603 v3 wins in platform capabilities rather than raw compute performance. Its quad-channel memory architecture provides 59.7 GB/s of bandwidth, which is 16.6% higher than the Pentium's 51.2 GB/s, a meaningful advantage for memory-bound workloads. ECC memory support ensures data integrity in mission-critical applications, and the 40 PCIe Gen 3 lanes allow for extensive expansion options. The 10 MB shared L3 cache is 2.5 times larger than the Pentium's 4 MB, potentially benefiting workloads with large data sets.

The core count difference is also relevant: the Xeon's 4 physical cores versus the Pentium's 2 physical cores with hyper-threading means the Xeon may handle sustained multi-threaded workloads with less thermal throttling, even though the benchmark scores are identical. The Xeon's higher base clock of 2.80 GHz without boost means consistent performance under load, whereas the Pentium's 1100 MHz base clock relies heavily on boost to reach its benchmark scores.