CPU Comparison

The Intel Pentium Gold G6600 and Intel Xeon E5645 represent two very different eras of Intel silicon, yet they land in the same performance tier. The data shows a surprising outcome: the older, server-oriented Xeon consistently outperforms the newer desktop Pentium in every head-to-head benchmark recorded. This is not a close contest; it is a systematic victory for the six-core Westmere chip.

Head-to-Head Benchmarks

The benchmark results are unambiguous, with the Intel Xeon E5645 winning all five recorded comparisons. In Cinebench R15 multicore, the Xeon scores 421 against the Pentium’s 361, a margin of 14.3%. That gap is consistent across every multi-core test. Cinebench R20 multicore shows the same 14.3% delta, with the Xeon posting 1758 to the Pentium’s 1507. Cinebench R23 multicore follows suit: 4187 for the Xeon versus 3589 for the Pentium, again a 14.3% difference.

The single-core results are more telling, as they highlight the architectural gulf. In Cinebench R20 single-core, the Xeon scores 248 while the Pentium manages 212, a 14.5% deficit. Cinebench R23 single-core shows a 14.4% gap, with the Xeon at 591 and the Pentium at 506. The Xeon even wins the single-core tests despite its much lower base clock of 2.40 GHz compared to the Pentium’s 4.20 GHz. This suggests the Xeon’s older architecture is not the limitation one might expect, or that the test conditions favor its design in ways the clock speed alone cannot predict.

Looking at the broader benchmark landscape, the two processors sit at the same percentile relative to all CPUs, both are at the 34th percentile. Their average benchmark scores are also close: the Pentium averages 1235, while the Xeon averages 1211. The Pentium’s nearest rival, the Intel Core i3-8109U, matches its average score exactly at 1235. The Xeon’s nearest rival, the Intel Core i3-7300T, matches its average at 1211. In direct comparison, the Xeon’s 5-0 win record in the head-to-head tests is decisive, but the overall averages suggest that in a broader suite of applications, the difference might narrow.

Architecture Differences

The foundational difference is in core count and process node. The Pentium Gold G6600 uses a 14 nm Comet Lake architecture with 2 cores and 4 threads. The Xeon E5645 uses a 32 nm Westmere-EP architecture with 6 cores and 12 threads. That is a threefold increase in physical cores and threads for the Xeon, which explains its multi-core advantage.

Cache configurations also diverge significantly. Both have 64 KB of L1 cache per core and 256 KB of L2 cache per core. However, the Xeon has 12 MB of shared L3 cache, while the Pentium has only 4 MB. This larger pool of cache likely helps the Xeon in workloads that benefit from shared data access across its six cores.

The memory subsystem reflects their different market positions. The Pentium supports DDR4 memory with dual-channel access and a bandwidth of 42.7 GB/s. The Xeon supports DDR3 with triple-channel access, though its bandwidth is not listed in the data. The Xeon also supports ECC memory, a feature absent on the Pentium. This makes the Xeon suited for error-sensitive server workloads.

PCIe support differs as well. The Pentium offers PCIe Gen 3 with 16 lanes from the CPU. The Xeon offers PCIe Gen 2, with no lane count specified. The integrated graphics also separate them: the Pentium includes UHD Graphics 630, while the Xeon has none. The Xeon’s socket is Intel Socket 1366, whereas the Pentium uses Intel Socket 1200, meaning they are not interchangeable in any system.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Xeon E5645 has 6 cores and 12 threads. The Intel Pentium Gold G6600 has 2 cores and 4 threads.

Q: Why does the Xeon win the single-core benchmarks despite its lower clock speed?

A: The data shows the Xeon winning single-core tests by about 14.4% to 14.5% despite a base clock of 2.40 GHz versus 4.20 GHz for the Pentium. The benchmark results indicate the Xeon’s architecture delivers higher per-thread performance in these specific Cinebench tests, though the exact reason is not detailed in the data.

Q: Do these processors support the same memory type?

A: No. The Pentium Gold G6600 supports DDR4 memory with dual-channel access. The Xeon E5645 supports DDR3 memory with triple-channel access.

Q: Is ECC memory supported on either processor?

A: Only the Intel Xeon E5645 supports ECC memory. The Pentium Gold G6600 does not have ECC support.

Q: Which processor has integrated graphics?

A: The Intel Pentium Gold G6600 includes UHD Graphics 630. The Intel Xeon E5645 has no integrated graphics.

Q: What is the production status of each chip?

A: The Intel Pentium Gold G6600 is listed as Active in production. The Intel Xeon E5645 is listed as End-of-life.

Specification Differences

• Cores: Pentium Gold G6600 has 2; Xeon E5645 has 6.
• Threads: Pentium Gold G6600 has 4; Xeon E5645 has 12.
• Base Clock: Pentium Gold G6600 is 4.20 GHz; Xeon E5645 is 2.40 GHz.
• Boost Clock: Pentium Gold G6600 has none listed; Xeon E5645 has 2.67 GHz.
• TDP: Pentium Gold G6600 is 58 W; Xeon E5645 is 80 W.
• Socket: Pentium Gold G6600 uses Intel Socket 1200; Xeon E5645 uses Intel Socket 1366.
• Process Node: Pentium Gold G6600 is 14 nm; Xeon E5645 is 32 nm.
• L3 Cache: Pentium Gold G6600 has 4 MB shared; Xeon E5645 has 12 MB shared.
• Memory Support: Pentium Gold G6600 uses DDR4; Xeon E5645 uses DDR3.
• Memory Bus: Pentium Gold G6600 is dual-channel; Xeon E5645 is triple-channel.
• Memory Bandwidth: Pentium Gold G6600 is 42.7 GB/s; Xeon E5645 has no listed value.
• ECC Memory: Pentium Gold G6600 does not support it; Xeon E5645 supports it.
• PCIe: Pentium Gold G6600 is Gen 3 with 16 lanes; Xeon E5645 is Gen 2 with no lane count.
• Integrated Graphics: Pentium Gold G6600 has UHD Graphics 630; Xeon E5645 has none.
• Market Segment: Pentium Gold G6600 is Desktop; Xeon E5645 is Server/Workstation.
• Production Status: Pentium Gold G6600 is Active; Xeon E5645 is End-of-life.
• Transistors: Pentium Gold G6600 has no listed count; Xeon E5645 has 1,170 million.
• Die Size: Pentium Gold G6600 has no listed size; Xeon E5645 is 239 mm².

The Verdict

The data is clear: if you are choosing purely on benchmark performance, the Intel Xeon E5645 is the superior processor. It wins every head-to-head Cinebench test by a margin of roughly 14.3% to 14.5%. The Xeon’s advantage is consistent across both multi-core and single-core workloads, which is a rare outcome when comparing a newer dual-core chip to an older six-core server part.

However, the Xeon is an end-of-life product on the Intel Socket 1366 platform, while the Pentium is active on the modern Intel Socket 1200 platform. The Pentium offers integrated graphics, DDR4 memory support, and a lower TDP of 58 W versus 80 W for the Xeon. The Xeon requires a separate graphics card and uses the older DDR3 memory standard. For a builder starting a new system today, the Pentium’s platform advantages are substantial, even if its raw compute performance lags.

The benchmark averages tell a slightly different story. The Pentium’s average benchmark score is 1235, while the Xeon’s is 1211. This means that in a broader set of tests beyond the five Cinebench runs, the Pentium might actually hold its own or even edge ahead. The head-to-head data is specific to Cinebench workloads, which may favor the Xeon’s core count more than other applications would.

Where Each One Wins

The Intel Xeon E5645 wins in every measured Cinebench scenario. Its 6 cores and 12 threads provide a clear advantage in multi-threaded rendering tasks, as shown by the 14.3% lead in Cinebench R15, R20, and R23 multicore tests. It also wins single-core tests by about 14.4%, which is counterintuitive given its lower clock speed, but the data supports it. The Xeon is the pick for any workload that is heavily threaded or that mirrors the Cinebench rendering pattern.

The Intel Pentium Gold G6600 does not win any head-to-head benchmark, but it has strengths the Xeon cannot match. It includes UHD Graphics 630, so a basic system can run without a discrete GPU. It supports DDR4 memory with 42.7 GB/s of bandwidth, which is a faster memory standard than the Xeon’s DDR3. Its 58 W TDP is lower, making it easier to cool and more efficient in a desktop chassis. The Pentium is also an active product on a current socket, meaning new motherboards are available, whereas the Xeon’s Socket 1366 platform is obsolete.

In practical terms, the Xeon is the better choice if you already have a Socket 1366 motherboard and need maximum compute performance for Cinebench-style workloads, and you do not mind using a discrete GPU. The Pentium is the better choice for a new, simple desktop build where integrated graphics, modern memory support, and lower power draw are priorities, and where the 14% performance deficit in Cinebench is acceptable. The data does not show any scenario where the Pentium wins a benchmark, so the decision comes down to platform features versus raw performance.