Intel Core i3-8300 vs Intel Core i5-6600T Comparison

The Intel Core i3-8300 and Intel Core i5-6600T are both quad-core, quad-thread desktop processors, but they represent different generations of Intel design. The data shows a clear overall performance leader: the i3-8300 wins all six head-to-head comparisons, with an average benchmark score of 1564 against the i5-6600T's 1563. Despite the i5-6600T carrying the higher-tier "i5" branding, the newer i3-8300 delivers consistently higher scores across every tested workload, making it the stronger choice for raw compute performance in this matchup.

Head-to-Head Benchmarks

The most striking pattern in the benchmark data is the uniformity of the i3-8300's victory. Across all six Cinebench tests, the i3-8300 wins by a margin between 13.4% and 14.3%. This is not a case of one processor excelling in a single niche; the lead is consistent whether the workload is single-threaded or multi-threaded.

In multi-core workloads, the i3-8300 posts 545 points in Cinebench R15 multi-core, a 14% advantage over the i5-6600T's 478 points. The gap widens slightly in absolute terms in newer tests: the i3-8300 scores 2271 in Cinebench R20 multi-core versus 1992 for the i5-6600T, again a 14% lead. In Cinebench R23 multi-core, the i3-8300 reaches 5408, while the i5-6600T manages 4745 — a difference of 663 points, which represents the same 14% margin.

Single-core performance tells a similar story, though the margins are slightly tighter. The i3-8300 wins Cinebench R15 single-core with 76 points against 67, a 13.4% lead. In Cinebench R20 single-core, the scores are 320 versus 280, a 14.3% advantage. The i3-8300's Cinebench R23 single-core score of 763 beats the i5-6600T's 669 by 14.1%.

It is importantly the i5-6600T has two additional benchmark entries in the data — Geekbench multi-core (3104) and single-core (1172) — but these are not part of the head-to-head comparison. The i3-8300's six wins out of six possible tests leave no ambiguity about which processor is faster in the measured categories. This is a clean sweep, and the consistency of the deltaPct values suggests the performance gap is structural rather than workload-specific.

FAQ

Q: Which processor is faster overall?

A: The Intel Core i3-8300. It wins all six head-to-head Cinebench tests, with an average benchmark score of 1564 versus 1563 for the i5-6600T. The per-test deltas range from 13.4% to 14.3% in the i3-8300's favor.

Q: Is the i5-6600T better at anything in the benchmark data?

A: No. The head-to-head results show the i5-6600T with zero wins across six tests. Its best result is an average benchmark score of 1563, which is only one point behind the i3-8300's 1564.

Q: How does the i3-8300 compare to its nearest rivals?

A: The i3-8300's nearest rival is the i5-6600T, with a deltaPct of 0. The AMD Ryzen 3 1300X is 0.1% behind, and the AMD Opteron 6276 is 0.3% behind. The AMD Opteron 6282 SE is 0.3% ahead. The i3-8300 sits at the 39th percentile of all CPUs.

Q: What is the difference in TDP between the two?

A: The i5-6600T has a TDP of 35 watts, while the i3-8300 has a TDP of 62 watts. This makes the i5-6600T significantly more power-efficient on paper, though it also runs at a lower base clock.

Q: Do both processors support ECC memory?

A: No. The i3-8300 supports ECC memory (true), while the i5-6600T does not (false). This is a notable feature difference for users who require error-correcting memory.

Q: What is the launch MSRP of each processor?

A: The i3-8300 has a launch MSRP of $138. The i5-6600T has a launch MSRP of $213.

Architecture Differences

The two processors come from different Intel microarchitectures. The i3-8300 uses Coffee Lake, while the i5-6600T uses Skylake. Both are built on the same 14 nm process node, but the die size differs significantly: the i3-8300 has a die size of 126 mm², while the i5-6600T's die is larger at 177 mm².

Cache configuration also differs. Both have 64 KB of L1 cache per core and 256 KB of L2 cache per core, but the shared L3 cache is larger on the i3-8300: 8 MB shared versus 6 MB shared on the i5-6600T. This extra 2 MB of L3 cache likely contributes to the i3-8300's performance advantage.

Memory support is another area of divergence. The i3-8300 supports DDR4 memory only, while the i5-6600T supports both DDR3 and DDR4. Memory bandwidth also favors the i3-8300 at 38.4 GB/s versus 34.1 GB/s for the i5-6600T. Both use dual-channel memory and have identical PCIe configurations: Gen 3 with 16 lanes (CPU only).

The integrated graphics differ as well. The i3-8300 comes with UHD Graphics 630, while the i5-6600T has UHD Graphics 530. Neither processor has an unlocked multiplier, and both are marked as end-of-life production status.

Specification Differences

The most obvious specification difference is the clock speed. The i3-8300 has a base clock of 3.70 GHz with no boost clock listed, while the i5-6600T has a base clock of 2.70 GHz and a boost clock of 3.50 GHz. This means the i3-8300's base clock is 1.0 GHz higher than the i5-6600T's base, and it is also 0.20 GHz higher than the i5-6600T's maximum boost.

TDP is another key differentiator. The i3-8300 is rated at 62 watts, while the i5-6600T is rated at 35 watts. This makes the i5-6600T a much lower-power part, which could be relevant for compact builds or systems with limited cooling.

The L3 cache differs: 8 MB shared on the i3-8300 versus 6 MB shared on the i5-6600T. ECC memory support is present on the i3-8300 but absent on the i5-6600T. Memory type support also differs, with the i3-8300 limited to DDR4 and the i5-6600T supporting both DDR3 and DDR4. The i3-8300 has a higher memory bandwidth of 38.4 GB/s versus 34.1 GB/s.

Release dates are far apart: the i5-6600T was released in July 2015, while the i3-8300 arrived in February 2018. The launch MSRP also differs, with the i3-8300 at $138 and the i5-6600T at $213. The part numbers are SR3XY for the i3-8300 and SR2L9 for the i5-6600T. Die size, integrated graphics model, and architecture are all different as well.

The Verdict

The data makes this straightforward: the Intel Core i3-8300 is the faster processor in every benchmark measured. It wins all six head-to-head tests with margins between 13.4% and 14.3%. Its average benchmark score of 1564 edges out the i5-6600T's 1563, and both sit at the 39th percentile of all CPUs. The i3-8300 also offers a larger L3 cache, higher memory bandwidth, ECC support, and a lower launch MSRP.

The i5-6600T's only clear advantages are its lower TDP of 35 watts and its support for DDR3 memory in addition to DDR4. It also has a boost clock of 3.50 GHz, which is higher than its base but still below the i3-8300's fixed 3.70 GHz base clock. For users who prioritize power efficiency or need DDR3 compatibility, the i5-6600T has a reason to exist. For anyone seeking raw CPU performance, the i3-8300 is the unambiguous pick based on the benchmark results.

Where Each One Wins

The i3-8300 wins in all performance-oriented scenarios. Its higher base clock of 3.70 GHz, larger 8 MB L3 cache, and 38.4 GB/s memory bandwidth give it a consistent edge in both single-core and multi-core Cinebench workloads. It is the better choice for tasks like rendering, compilation, or any CPU-bound application where the 14% performance delta will translate into measurable time savings. The ECC memory support also makes it suitable for systems where data integrity is a concern.

The i5-6600T wins in efficiency-focused scenarios. Its 35-watt TDP is nearly half the i3-8300's 62 watts, making it a better fit for passively cooled or small-form-factor builds where heat output matters more than peak performance. Its support for DDR3 memory opens upgrade paths for older platforms or cheaper memory kits. The i5-6600T also has a boost clock of 3.50 GHz, which helps close the gap in lightly threaded workloads, though not enough to overcome the i3-8300's lead.

In practical terms, the i3-8300 is the processor to buy for a main desktop that will handle demanding applications. The i5-6600T is the processor to consider for a low-power secondary rig or a system constrained by cooling and power delivery. The benchmark data does not support choosing the i5-6600T for performance reasons; its strengths lie entirely in power consumption and memory flexibility.