Intel Core i7-5820K vs Intel Core i7-9700T Comparison

FAQ

Q: Which processor has more physical cores, and how does that affect multi-threaded performance?

A: The Intel Core i7-9700T has 8 cores and 8 threads, while the Intel Core i7-5820K has 6 cores and 12 threads. Despite the core-count disadvantage, the 5820K wins 4 of 5 multi-core benchmark comparisons, including Cinebench R20 multi-core (3508 vs 3496) and Cinebench R23 multi-core (8354 vs 8325), suggesting its 12 threads compensate for fewer physical cores.

Q: How large is the single-core performance gap between the two CPUs?

A: The 9700T leads significantly in Geekbench single-core, scoring 1392 against 1174 for the 5820K — a 18.6% advantage. However, in Cinebench R23 single-core, the 5820K edges ahead at 1179 versus 1175, a mere 0.3% difference. The results are test-dependent, with the 9700T showing a clear lead only in Geekbench.

Q: What is the thermal design power (TDP) difference, and what does that imply for system requirements?

A: The 9700T has a 35W TDP, while the 5820K draws 140W. That is a fourfold difference, meaning the 5820K requires substantially more robust cooling and power delivery. The 9700T’s low TDP makes it suitable for compact or passively cooled systems, whereas the 5820K demands a serious aftermarket cooler.

Q: Do both processors support DDR4 memory, and how does memory bandwidth differ?

A: Both support DDR4 memory. The 5820K uses a quad-channel memory bus delivering 68.3 GB/s, while the 9700T uses dual-channel with 42.7 GB/s. The 5820K offers 60% more theoretical memory bandwidth, which can benefit memory-intensive workloads like large dataset processing.

Q: Which processor has integrated graphics, and how does that affect system design?

A: The 9700T includes Intel UHD Graphics 630, while the 5820K has no integrated graphics. This means a system based on the 5820K always requires a discrete GPU, whereas the 9700T can operate without one for basic display output or troubleshooting.

Q: How do the two compare in overall benchmark averages and percentile rankings?

A: The 9700T has an average benchmark score of 2668 and sits at the 50th percentile of all CPUs. The 5820K averages 2642 and ranks at the 49th percentile. The 9700T is marginally ahead in aggregate, but the 5820K’s closest rivals include the Intel Xeon E-2274G (2643) and Core i9-8950HK (2641), showing it performs in a similar tier.

Architecture Differences

The Intel Core i7-9700T and Intel Core i7-5820K come from different architectural eras. The 9700T is built on Coffee Lake, a 14nm process, with a die size of 180.3 mm². The 5820K uses Haswell-E, a 22nm process, with a substantially larger die at 356 mm² and 2,600 million transistors. This generational leap gives the 9700T a process advantage, enabling higher clock speeds at far lower power draw.

Core and thread configurations diverge sharply. The 9700T packs 8 physical cores but no hyper-threading, yielding 8 threads. The 5820K has 6 cores but supports 12 threads via hyper-threading. This makes the 5820K’s thread count 50% higher, which explains its edge in multi-threaded Cinebench tests despite fewer physical cores.

Cache hierarchies also differ. Both have 64 KB of L1 and 256 KB of L2 per core, but the 5820K offers 15 MB of shared L3 cache versus 12 MB on the 9700T. That extra 3 MB could help in workloads with large working sets, though the 9700T’s newer architecture may use its cache more efficiently.

Memory subsystems reflect their platform positioning. The 9700T uses dual-channel DDR4 with 42.7 GB/s bandwidth, while the 5820K supports quad-channel DDR4 at 68.3 GB/s. The 5820K also provides 28 PCIe Gen 3 lanes (CPU only) versus 16 on the 9700T, allowing more expansion cards or NVMe drives at full bandwidth.

The 9700T includes integrated UHD Graphics 630, while the 5820K has none. This is a practical difference: the 9700T can run headless or with basic display, while the 5820K mandates a separate graphics card. The 9700T also features a locked multiplier, whereas the 5820K has an unlocked multiplier for overclocking.

Release timing separates them by nearly five years, with the 9700T launching on 2019-04-22 and the 5820K on 2014-08-31. Both are end-of-life, but the 9700T represents a much later design point with refined power efficiency.

The Verdict

The data presents a nuanced picture. The Intel Core i7-5820K wins 5 of 8 head-to-head benchmarks, including all three Cinebench multi-core tests and two single-core tests. Its hyper-threading advantage (12 threads vs 8) delivers consistent, if narrow, wins in Cinebench R15 (841 vs 839), R20 (3508 vs 3496), and R23 (8354 vs 8325). The 5820K also leads in Cinebench R20 single-core (495 vs 493) and R23 single-core (1179 vs 1175).

However, the Intel Core i7-9700T wins the Geekbench tests decisively, particularly single-core (1392 vs 1174, an 18.6% margin) and multi-core (5503 vs 5464, a 0.7% edge). In aggregate, the 9700T’s average benchmark score (2668) slightly exceeds the 5820K’s (2642), placing it one percentile higher.

For users prioritizing Cinebench-style rendering workloads, the 5820K is the data-backed choice, though its 140W TDP demands serious cooling. For users who value single-core responsiveness in Geekbench-style tasks or need integrated graphics and low power consumption (35W TDP), the 9700T is clearly superior. The 5820K’s quad-channel memory and 28 PCIe lanes also make it attractive for memory-bandwidth-heavy applications or systems with many expansion devices.

The 9700T is the pick for energy-conscious builds or those avoiding a discrete GPU. The 5820K suits overclockers (unlocked multiplier) and users needing maximum memory bandwidth or PCIe lane count. Both are end-of-life, but their benchmark profiles suggest different ideal environments.

Specification Differences

| Specification | Intel Core i7-9700T | Intel Core i7-5820K |

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

| Cores | 8 | 6 |

| Threads | 8 | 12 |

| Base Clock | 2000 MHz | 3300 MHz |

| Boost Clock | 4300 MHz | 3600 MHz |

| TDP | 35W | 140W |

| Socket | Intel Socket 1151 | Intel Socket 2011-3 |

| Architecture | Coffee Lake | Haswell |

| Process Node | 14 nm | 22 nm |

| Die Size | 180.3 mm² | 356 mm² |

| Transistors | — | 2,600 million |

| L3 Cache | 12 MB (shared) | 15 MB (shared) |

| Memory Bus | Dual-channel | Quad-channel |

| Memory Bandwidth | 42.7 GB/s | 68.3 GB/s |

| PCIe Lanes | 16 (Gen 3) | 28 (Gen 3) |

| Integrated Graphics | UHD Graphics 630 | None |

| Multiplier | Locked | Unlocked |

| Launch MSRP | $323 | — |

Head-to-Head Benchmarks

The Cinebench R15 multi-core test shows an almost perfect tie: the 5820K scores 841 against the 9700T’s 839, a -0.2% delta. This is remarkable given the 9700T’s 8 cores versus 6, indicating hyper-threading fully closes the gap. The single-core R15 result is a dead heat at 118 for both.

Moving to Cinebench R20, the 5820K extends its multi-core lead to 3508 versus 3496 (-0.3%), and takes single-core at 495 versus 493 (-0.4%). The pattern repeats in Cinebench R23: 8354 vs 8325 multi-core (-0.3%) and 1179 vs 1175 single-core (-0.3%). These margins are tiny — under half a percentage point — but consistent across all three Cinebench versions.

The Geekbench results flip the narrative. The 9700T wins multi-core at 5503 against 5464, a 0.7% advantage. The single-core gap is enormous: 1392 versus 1174, a 18.6% delta in favor of the 9700T. This is the single largest difference in any benchmark, dwarfing the Cinebench margins. It suggests the 9700T’s architecture handles Geekbench’s workload far more efficiently, possibly due to higher boost clocks (4.3 GHz vs 3.6 GHz).

Across all 8 benchmarks, the 5820K wins 5 and the 9700T wins 3. Yet the 9700T’s wins include the largest margin, while the 5820K’s wins are all within 0.4%. This asymmetry means the 9700T’s aggregate score (2668) exceeds the 5820K’s (2642) despite losing more benchmarks — a fascinating statistical outcome.

Where Each One Wins

The Intel Core i7-5820K dominates in Cinebench workloads, winning all three multi-core tests and two single-core tests. This makes it the superior choice for rendering, 3D modeling, and video encoding tasks that scale with thread count. Its 12 threads clearly outperform the 9700T’s 8 threads in these scenarios, even at lower clock speeds. The 5820K’s quad-channel memory (68.3 GB/s) and 28 PCIe lanes further benefit bandwidth-hungry tasks like scientific computing or multi-GPU setups.

The Intel Core i7-9700T wins decisively in Geekbench, especially single-core with an 18.6% margin. This indicates advantages in applications that favor high boost clocks (4.3 GHz) and modern architectural efficiency. The 9700T is also the clear winner in power efficiency, with a 35W TDP versus 140W — a 4x reduction that enables fanless or small-form-factor builds. Its integrated UHD Graphics 630 allows basic display output without a discrete GPU, which the 5820K cannot offer.

For memory-intensive workloads, the 5820K’s 68.3 GB/s bandwidth versus 42.7 GB/s is a substantial advantage. For single-threaded responsiveness in everyday tasks, the 9700T’s Geekbench single-core score suggests snappier performance. The 5820K’s unlocked multiplier appeals to overclockers, while the 9700T’s locked multiplier means stock clocks are the ceiling.

In summary, the 5820K wins where multithreading and memory bandwidth matter; the 9700T wins where clock speed, efficiency, and integrated graphics matter. The data supports each processor’s distinct niche, with no universal victor.