CPU Comparison

The Intel Xeon E5645 and Intel Core i5-3330 represent two distinct eras of Intel design, but the benchmark data reveals a decisive performance hierarchy. The Xeon E5645, a six-core Westmere-EP server part, wins every single head-to-head benchmark in the Cinebench suite against the quad-core Ivy Bridge desktop processor. Across five tests spanning R15, R20, and R23, the Xeon's victory margins are remarkably consistent, ranging from 19.9% to 20.4%. While the Core i5-3330 benefits from a newer microarchitecture and a higher base clock, the Xeon's additional cores and threads prove decisive in rendering workloads. The data indicates a clear overall winner, though the specific use cases for each processor differ significantly.

Head-to-Head Benchmarks

The most striking aspect of this comparison is the uniformity of the Xeon E5645's advantage. In the Cinebench R15 multi-core test, the Xeon scores 421 against the Core i5's 351, a delta of 19.9%. This pattern holds almost exactly in the newer Cinebench R20 multi-core test, where the Xeon's 1758 points eclipse the Core i5's 1464, yielding a 20.1% lead. The R23 multi-core benchmark confirms the trend, with the Xeon posting 4187 versus 3486, again a 20.1% advantage. These results strongly suggest that the Xeon's six physical cores and twelve threads provide a scalable performance headroom that the Core i5's four cores and four threads cannot match, regardless of the rendering engine's generation.

Single-core performance, however, is where the Core i5's newer architecture might be expected to shine. The data shows otherwise. In Cinebench R20 single-core, the Xeon E5645 scores 248, while the Core i5-3330 manages 206. This translates to a 20.4% lead for the older Xeon. The R23 single-core test tells a similar story, with the Xeon's 591 points beating the Core i5's 492 by 20.1%. This is a surprising result given that the Core i5 has a base clock of 3.00 GHz and a boost clock of 3.20 GHz, compared to the Xeon's 2.40 GHz base and 2.67 GHz boost. The benchmark results indicate that the Xeon's architecture, despite its lower clock speeds, delivers superior instructions per clock in these specific tests, or that the Cinebench workload is sufficiently optimized for its feature set. The consistency of the ~20% delta across all tests points to a fundamental performance gap that clock speed alone cannot bridge.

The average benchmark scores further contextualize these two processors. The Xeon E5645 holds an average benchmark score of 1211, while the Core i5-3330 sits at 1200. This places them within 0.9% of each other on average, which is interesting given the large deltas in the Cinebench tests. The explanation lies in their respective nearest rivals. The Xeon's closest competitor is the Intel Core i3-7300T, with a delta of 0%, while the Core i5-3330's nearest rival is the AMD Athlon PRO 200GE, also at a 0% delta. These rival relationships suggest that in the broader benchmark database, these CPUs are positioned in a similar performance tier, even though their specific strengths and weaknesses in Cinebench differ markedly. The Xeon's percentile rank of 34 and the Core i5's percentile rank of 34 also confirm that they sit at the same level relative to all other CPUs in the database, which underscores that the head-to-head Cinebench results represent a specific workload profile rather than a general overall superiority in all tasks.

FAQ

Q: Which processor wins the most benchmarks in the head-to-head comparison?

A: The Intel Xeon E5645 wins all five head-to-head benchmarks. It takes the Cinebench R15 multi-core, R20 multi-core, R20 single-core, R23 multi-core, and R23 single-core tests. The Intel Core i5-3330 does not win any of the five compared tests.

Q: What is the performance difference in the Cinebench R23 multi-core test?

A: The Xeon E5645 scores 4187, while the Core i5-3330 scores 3486. This results in a 20.1% advantage for the Xeon E5645, which is consistent with the deltas seen in the other multi-core tests.

Q: How do the two processors compare in average benchmark score?

A: The Xeon E5645 has an average benchmark score of 1211, and the Core i5-3330 has an average score of 1200. This is a difference of just 11 points, placing them very close in overall database rankings.

Q: Does the Core i5-3330 have a higher boost clock than the Xeon E5645?

A: Yes, the Core i5-3330 has a boost clock of 3.20 GHz, which is higher than the Xeon E5645's boost clock of 2.67 GHz. Despite this clock advantage, the Xeon still wins all single-core benchmarks in this comparison.

Q: What is the percentile ranking for each processor?

A: Both the Intel Xeon E5645 and the Intel Core i5-3330 have a percentile rank of 34, meaning they perform better than 34% of all CPUs in the benchmark database.

Q: Which processor has a higher core and thread count?

A: The Intel Xeon E5645 has 6 cores and 12 threads. The Intel Core i5-3330 has 4 cores and 4 threads. The Xeon's higher thread count is a significant factor in its multi-core benchmark victories.

Where Each One Wins

The Intel Xeon E5645 is the clear winner for multi-threaded rendering workloads. The data shows a consistent 20% lead in all multi-core Cinebench tests, which directly translates to faster performance in 3D rendering, video encoding, and other tasks that can utilize its 12 threads. Its 6-core, 12-thread configuration provides a scalable advantage that the Core i5's 4-core, 4-thread setup cannot match. For a workstation handling content creation or scientific computing, the Xeon's multi-core dominance makes it the superior choice.

The Intel Core i5-3330, despite losing all benchmarks, has its own strengths based on its design and platform. It operates on the Intel Socket 1155 platform with a lower TDP of 77 watts, compared to the Xeon's 80 watts. It also features integrated graphics in the form of Intel HD 2500, making it a viable solution for a basic desktop system where a discrete GPU is not required. Its dual-channel memory bus and PCIe Gen 3 support with 16 lanes (CPU only) make it suited for a standard consumer desktop build. The Xeon requires a discrete GPU and is aimed at the server/workstation segment, making the Core i5 the more practical choice for a general-purpose desktop PC where the multi-core performance gap is not the primary concern.

Specification Differences

The two processors differ significantly across their core specifications. The most fundamental difference is in core and thread counts, where the Xeon E5645 offers 6 cores and 12 threads, while the Core i5-3330 offers 4 cores and 4 threads. Clock speeds also differ, with the Core i5 having a base clock of 3.00 GHz and a boost clock of 3.20 GHz, while the Xeon is rated at 2.40 GHz base and 2.67 GHz boost. The Xeon has a higher TDP of 80 watts, compared to the Core i5's 77 watts. Regarding cache, the Xeon has a significantly larger L3 cache of 12 MB (shared), whereas the Core i5 has a 6 MB (shared) L3 cache. Both have 64 KB of L1 cache and 256 KB of L2 cache per core.

The memory support also differs, with both supporting DDR3, but the Xeon utilizes a triple-channel memory bus while the Core i5 uses a dual-channel bus. The Xeon supports ECC memory, a feature absent on the Core i5. PCIe support is another differentiator, with the Xeon offering Gen 2 and the Core i5 offering Gen 3 with 16 lanes (CPU only). The Core i5 includes integrated graphics (Intel HD 2500), while the Xeon has none. The sockets are incompatible: the Xeon uses Intel Socket 1366, and the Core i5 uses Intel Socket 1155. The market segments are also distinct, with the Xeon aimed at Server/Workstation and the Core i5 at Desktop. Finally, the processing nodes differ, with the Xeon built on a 32 nm process and the Core i5 on a 22 nm process.

Architecture Differences

The architectural differences between these two CPUs are generational and structural. The Xeon E5645 is based on the Westmere architecture, with the codename Westmere-EP, and belongs to the Xeon (Westmere-EP) generation. In contrast, the Core i5-3330 is based on the Ivy Bridge architecture and belongs to the Core i5 (Ivy Bridge) generation. This generational gap is reflected in their process nodes: the Xeon uses a 32 nm process with a die size of 239 mm², while the Core i5 uses a smaller 22 nm process with a die size of 133 mm². The Xeon also features a higher transistor count of 1,170 million, whereas the Core i5's transistor count is not listed in the data.

The core design philosophies also differ. The Xeon's Westmere-EP architecture is designed for multi-socket server environments, emphasizing throughput and scalability with its 6 cores and 12 threads. The Ivy Bridge architecture in the Core i5 is a mainstream desktop design focused on efficiency and balanced performance, offering only 4 cores and 4 threads without Hyper-Threading. The Xeon's larger 12 MB L3 cache is a direct result of its server-oriented design, aimed at feeding its many cores in multi-threaded workloads. The Core i5's smaller 6 MB L3 cache is sufficient for its fewer threads. The Xeon supports ECC memory, a key feature for data integrity in server environments, while the Core i5 does not. The Core i5's integrated graphics represent a major architectural feature absent on the Xeon, which is a server part that assumes a discrete GPU is present. The PCIe generations also highlight the age difference, with the Xeon using Gen 2 and the Core i5 using the newer Gen 3 standard.