Intel Core i3-9300 vs Intel Core i5-6600T Comparison

The Intel Core i5-6600T and Intel Core i3-9300 are both desktop processors on the Intel Socket 1151 platform, yet they represent different generations and design philosophies. The i5-6600T is a Skylake-era part aimed at low-power systems, while the i3-9300 is a Coffee Lake Refresh chip targeting mainstream performance. Benchmark data shows a clear and consistent performance gap between the two, with the i3-9300 winning all six head-to-head tests. This analysis breaks down those results, explores where each chip fits, and examines the architectural differences that explain the outcome.

Head-to-Head Benchmarks

The head-to-head results are unambiguous: the Intel Core i3-9300 wins every single benchmark in the comparison. The largest margin comes in Cinebench R20 single-core, where the i3-9300 scores 318 against the i5-6600T’s 280, a delta of -11.9% from the i5-6600T’s perspective. That pattern repeats across all Cinebench versions. In Cinebench R15 multi-core, the i3-9300 posts 541 versus 478, a -11.6% gap. The single-core R15 test shows 76 against 67, a -11.8% difference.

The consistency is striking. In Cinebench R20 multi-core, the i3-9300 scores 2257 while the i5-6600T manages 1992, again a -11.7% delta. Moving to Cinebench R23, the multi-core result is 5374 for the i3-9300 and 4745 for the i5-6600T, with the same -11.7% gap. The single-core R23 test shows 758 versus 669, also -11.7%. Every benchmark lands within a narrow band of -11.6% to -11.9%, suggesting the performance difference is systemic rather than workload-specific.

The i5-6600T does have one additional benchmark not present in the i3-9300’s data set: Geekbench. It scores 3104 in multi-core and 1172 in single-core. These results cannot be compared directly to the i3-9300 because the latter lacks Geekbench scores in the data. Still, they provide context for the i5-6600T’s overall capability. Its average benchmark score is 1563, while the i3-9300’s average is 1554 — nearly identical despite the i3-9300 winning every head-to-head test. That happens because the i5-6600T’s Geekbench results are included in its average, while the i3-9300’s average relies solely on Cinebench scores.

Both processors sit at the 39th percentile among all CPUs, meaning their overall performance ranking is the same despite the i3-9300’s clear advantage in the shared tests. The nearest rivals for the i5-6600T include the Intel Core i3-8300, which scores 1564 with a -0.1% delta, and the AMD Ryzen 3 1300X at 1562 with a +0.1% delta. The i3-9300’s rivals include the Intel Xeon E3-1268L v5 at 1557 (-0.2%) and the AMD FX-8350 also at 1557 (-0.2%). This places both chips in a similar performance tier overall, yet the i3-9300 is consistently faster in the Cinebench suite.

Where Each One Wins

The Intel Core i3-9300 wins in every shared benchmark category. This includes multi-core workloads, where its 541 R15, 2257 R20, and 5374 R23 scores top the i5-6600T’s 478, 1992, and 4745 respectively. It also wins in single-core tests, with 76 R15, 318 R20, and 758 R23 versus 67, 280, and 669. If a workload relies heavily on raw CPU throughput, the data points squarely at the i3-9300.

The i5-6600T, however, has no head-to-head wins. Its only distinct advantage appears in the Geekbench figures, but those are not comparable to the i3-9300 since the latter lacks such scores. The i5-6600T does have a significantly lower TDP of 35 watts versus the i3-9300’s 62 watts. That makes it the more power-efficient choice for systems where heat and energy draw are primary concerns. The data also shows the i5-6600T supports DDR3 in addition to DDR4, which could matter for users repurposing older memory modules.

For single-threaded responsiveness, the i3-9300 is the clear pick. Its higher base clock of 3.70 GHz and boost clock of 4.30 GHz, compared to 2.70 GHz and 3.50 GHz on the i5-6600T, explain the consistent single-core margins. For multi-threaded tasks, both chips have 4 cores and 4 threads, so the i3-9300’s advantage comes purely from clock speed and architecture improvements, not core count. The i5-6600T’s lower power envelope might make it suitable for compact builds, but performance-oriented users will find no scenario in the data where it outpaces the i3-9300.

Architecture Differences

The two processors come from different Intel architectures. The i5-6600T uses Skylake, while the i3-9300 is built on Coffee Lake. Both are manufactured on a 14 nm process at Intel, but the die sizes differ: the i5-6600T has a 177 mm² die, while the i3-9300 is smaller at 126 mm². That smaller die likely contributes to the i3-9300’s higher clock speeds despite its higher TDP.

Cache configurations also differ. Each core has 64 KB of L1 and 256 KB of L2 in both chips, but the shared L3 cache is larger on the i3-9300 at 8 MB versus 6 MB on the i5-6600T. This extra cache can improve performance in workloads that repeatedly access the same data. Memory support diverges as well: the i5-6600T supports both DDR3 and DDR4, while the i3-9300 only supports DDR4. The i3-9300 also has higher memory bandwidth at 38.4 GB/s compared to 34.1 GB/s on the i5-6600T, and it supports ECC memory, which the i5-6600T does not.

Integrated graphics differ too. The i5-6600T includes UHD Graphics 530, while the i3-9300 has UHD 630. Both chips use PCIe Gen 3 with 16 lanes, and neither has an unlocked multiplier. The production status for both is end-of-life, and both use the Intel Socket 1151. The i3-9300 launched in April 2019 with a launch MSRP of $143, while the i5-6600T launched in July 2015 with a launch MSRP of $213. Neither part is currently in production, but the i3-9300 is the newer design.

FAQ

Q: Which CPU is faster in multi-core benchmarks?

A: The Intel Core i3-9300 wins all multi-core tests. It scores 541 in Cinebench R15, 2257 in R20, and 5374 in R23, versus 478, 1992, and 4745 for the i5-6600T. The delta is consistently around -11.7%.

Q: How do the single-core scores compare?

A: The i3-9300 leads in every single-core test. It posts 76 in Cinebench R15, 318 in R20, and 758 in R23, while the i5-6600T scores 67, 280, and 669 respectively. The performance gap ranges from -11.7% to -11.9%.

Q: Do both CPUs have the same core and thread counts?

A: Yes, both have 4 cores and 4 threads. The i3-9300’s advantage comes from higher clock speeds and a newer architecture, not additional cores.

Q: What memory types does each support?

A: The i5-6600T supports both DDR3 and DDR4, while the i3-9300 only supports DDR4. The i3-9300 also has higher memory bandwidth at 38.4 GB/s versus 34.1 GB/s.

Q: Is there a difference in integrated graphics?

A: Yes. The i5-6600T has UHD Graphics 530, while the i3-9300 has UHD 630. Neither chip has an unlocked multiplier.

Q: Which CPU has a lower power draw?

A: The i5-6600T has a TDP of 35 watts, compared to 62 watts for the i3-9300. This makes the i5-6600T more power-efficient, though it comes at the cost of performance.

The Verdict

The data is decisive: the Intel Core i3-9300 outperforms the Intel Core i5-6600T in every benchmark they share. The margins are uniform, hovering near -11.7% across all Cinebench tests, which points to a consistent architectural and clock-speed advantage rather than a workload-specific quirk. Users who prioritize raw CPU performance should choose the i3-9300 without hesitation.

The i5-6600T does have reasons to exist. Its 35-watt TDP is nearly half the i3-9300’s 62 watts, making it a fit for low-power or thermally constrained systems. It also supports DDR3 memory, which could be a deciding factor for someone reusing older RAM. However, those advantages come with a substantial performance penalty that no benchmark in the data offsets.

Given that both chips sit at the 39th percentile and have nearly identical average benchmark scores — 1563 for the i5-6600T and 1554 for the i3-9300 — the overall performance tier is similar. But within that tier, the i3-9300 is the stronger performer in every measurable way. The i5-6600T is only the better choice when power efficiency or DDR3 compatibility outweighs the need for speed.

Specification Differences

| Specification | Intel Core i5-6600T | Intel Core i3-9300 |

|---|---|---|

| Base Clock | 2.70 GHz | 3.70 GHz |

| Boost Clock | 3.50 GHz | 4.30 GHz |

| TDP | 35 W | 62 W |

| Architecture | Skylake | Coffee Lake |

| Die Size | 177 mm² | 126 mm² |

| L3 Cache | 6 MB (shared) | 8 MB (shared) |

| Memory Support | DDR3, DDR4 | DDR4 |

| Memory Bandwidth | 34.1 GB/s | 38.4 GB/s |

| ECC Memory | No | Yes |

| Integrated Graphics | UHD Graphics 530 | UHD 630 |

| Release Date | 2015-07-01 | 2019-04-22 |

| Launch MSRP | $213 | $143 |