Intel Core i7-6900K vs Intel Core i9-9900 Comparison

Head-to-Head Benchmarks

The head-to-head data records eight benchmark comparisons between the Intel Core i9-9900 and the Intel Core i7-6900K. The i9-9900 wins seven of those eight tests, with the i7-6900K taking a single victory. The margins, however, tell a more nuanced story than the raw win count.

In the Cinebench suite, the i9-9900 is consistently ahead across all three versions and both single-core and multi-core tests. In Cinebench R15 multi-core, the i9-9900 scores 1361 against 1254 for the i7-6900K, a delta of 8.5%. Single-core in the same test shows 192 versus 176, a 9.1% advantage. Moving to Cinebench R20, the multi-core gap is 5673 versus 5226, an 8.6% edge, and single-core is 800 versus 737, again 8.5%. Cinebench R23 repeats the pattern: multi-core 13509 against 12444 (8.6%) and single-core 1907 versus 1756 (8.6%). These are remarkably consistent margins, all falling between 8.5% and 9.1%. The i9-9900 does not just win; it wins by nearly the same percentage in every rendering workload, which points to a clock-speed advantage that scales uniformly across thread counts.

The single exception is Geekbench multi-core, where the i7-6900K posts 8774 against the i9-9900's 8175, a delta of -6.8% in favor of the older chip. This is the only test where the i7-6900K leads, and it is a substantial lead. The contrast with the Cinebench results is striking: the i7-6900K wins the Geekbench multi-core test by a larger margin than the i9-9900 wins any single Cinebench test except single-core R15. The i9-9900's largest victory is Geekbench single-core, where it scores 1687 against 1392, a 21.2% advantage. That is more than double any other margin in the entire comparison.

Looking at the average benchmark score, the i9-9900 sits at 4163, while the i7-6900K records 3970. The i9-9900's nearest rivals in the database include the Intel Core i5-11500H (4187, -0.6%), the AMD Ryzen 9 5980HS (4121, 1%), the AMD Ryzen 7 PRO 2700X (4114, 1.2%), and the Intel Core i5-12500T (4216, -1.3%). The i7-6900K, by comparison, sits near the AMD Ryzen 7 PRO 5875U (3971, 0%), the AMD Ryzen 5 PRO 4650G (3977, -0.2%), the Intel Xeon E5-2669 v3 (3959, 0.3%), and the AMD Ryzen 3 7330U (3958, 0.3%). Both processors land at the 57th percentile among all CPUs in the database, which places them in the same overall performance tier despite the different benchmark distributions.

The key takeaway from the head-to-head data is that the i9-9900 dominates in rendering and single-threaded workloads, while the i7-6900K shows a specific strength in Geekbench's multi-core measurement. The i9-9900's 21.2% single-core Geekbench lead is the largest delta recorded in this comparison, and it underscores the generational clock improvement between the two parts.

Architecture Differences

The two processors come from different architectural eras. The Intel Core i9-9900 uses the Coffee Lake architecture, specifically the Coffee Lake-R codename, and belongs to the Core i9 (Coffee Lake Refresh) generation. It is built on a 14 nm process node with a die size of 180.3 mm². The Intel Core i7-6900K uses the Broadwell architecture with the Broadwell-E codename, part of the Core i7 (Broadwell-E) generation. It also uses a 14 nm process node, but the die is larger at 246 mm². The i7-6900K has a transistor count of 3,400 million; the i9-9900's transistor count is not recorded in the database.

Both chips have 8 cores and 16 threads, so the fundamental compute unit count is identical. The cache hierarchy, however, differs at the L3 level. The i9-9900 has 16 MB of shared L3 cache, while the i7-6900K has 20 MB of shared L3 cache. L1 and L2 caches are the same on both: 64 KB per core for L1 and 256 KB per core for L2.

The sockets are entirely different. The i9-9900 uses Intel Socket 1151, while the i7-6900K uses Intel Socket 2011-3. This is a critical platform distinction: the two chips cannot be installed in the same motherboard. The i9-9900 has a base clock of 3.10 GHz and a boost clock of 5.00 GHz. The i7-6900K has a base clock of 3.20 GHz and a boost clock of 3.70 GHz. The i9-9900's boost clock is dramatically higher, and this is the primary driver behind its single-core performance advantage. The i7-6900K actually starts with a slightly higher base clock, but its boost ceiling is 1.30 GHz lower.

Thermal design power differs substantially. The i9-9900 is rated at 65 W, while the i7-6900K is rated at 140 W. This is a major efficiency gap: the newer chip delivers higher performance in most tests while consuming less than half the thermal envelope. The i9-9900 also includes integrated graphics (UHD Graphics 630), while the i7-6900K has no integrated graphics at all. The i9-9900 has a locked multiplier, while the i7-6900K has an unlocked multiplier, meaning the older chip is designed for overclocking while the newer one is not.

Memory support also differs. Both support DDR4, but the i9-9900 uses a dual-channel memory bus with 42.7 GB/s of bandwidth, while the i7-6900K uses a quad-channel memory bus with 76.8 GB/s of bandwidth. The i7-6900K's memory bandwidth is nearly double that of the i9-9900. Neither chip supports ECC memory. PCIe lane allocation is another differentiator: the i9-9900 provides Gen 3 with 16 lanes (CPU only), while the i7-6900K provides Gen 3 with 40 lanes (CPU only). The i7-6900K offers substantially more PCIe connectivity for expansion.

Release dates place the i9-9900 in April 2019 and the i7-6900K in May 2016, a gap of roughly three years. Both are marked end-of-life in the database. The i9-9900's launch MSRP is $423. The i7-6900K's launch MSRP is $1089. The part numbers are SRG18 for the i9-9900 and SR2PB for the i7-6900K.

Where Each One Wins

The i9-9900 is the clear winner in rendering workloads. Its Cinebench R15, R20, and R23 multi-core scores all exceed the i7-6900K by approximately 8.5% to 8.6%. For users running CPU-based rendering, video encoding, or other heavily threaded production tasks that behave like Cinebench, the i9-9900 is the faster chip. The consistency of the margin across all three Cinebench versions suggests the advantage holds across different rendering engines and workload scales.

The i9-9900 is also the winner in single-threaded performance. Its single-core scores are higher across every recorded test: Cinebench R15 (192 versus 176), R20 (800 versus 737), R23 (1907 versus 1756), and Geekbench (1687 versus 1392). The Geekbench single-core gap is the largest in the entire comparison at 21.2%. Applications that depend on single-thread speed, such as older games, certain simulation software, and lightly threaded productivity tools, will favor the i9-9900 significantly.

The i7-6900K's single win is Geekbench multi-core, where it scores 8774 against 8175. This is a 6.8% advantage. The Geekbench multi-core test apparently exercises memory bandwidth or other platform characteristics in a way that favors the i7-6900K's quad-channel memory configuration and larger L3 cache. Users whose workloads resemble Geekbench's multi-core pattern, particularly memory-bandwidth-sensitive parallel tasks, may see better results on the i7-6900K.

The i7-6900K also offers platform advantages that do not show up in CPU-only benchmarks. Its quad-channel memory bus provides 76.8 GB/s of bandwidth, nearly double the i9-9900's 42.7 GB/s. Its 40 PCIe Gen 3 lanes allow for more expansion options, including multiple GPUs or high-speed storage arrays. The unlocked multiplier gives overclocking headroom, which can close some of the performance gap in tuned systems. The larger 20 MB L3 cache may help in workloads with large working sets that fit within cache.

For most users, the i9-9900 is the better all-around processor. It wins seven of eight benchmarks, has a much higher boost clock, runs at a far lower TDP, and includes integrated graphics. The i7-6900K is the better choice only in specific scenarios: Geekbench-style multi-core workloads, memory-bandwidth-heavy tasks, systems requiring extensive PCIe expansion, or overclocking-focused builds where the user intends to push the chip beyond stock settings.

FAQ

Q: Which processor is faster in Cinebench R23 multi-core?

A: The Intel Core i9-9900 scores 13509 in Cinebench R23 multi-core, against 12444 for the Intel Core i7-6900K, an 8.6% advantage.

Q: Does the Intel Core i7-6900K win any benchmark against the i9-9900?

A: Yes. The i7-6900K wins Geekbench multi-core with a score of 8774, compared to 8175 for the i9-9900, a delta of -6.8% in favor of the i7-6900K.

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

A: In Geekbench single-core, the i9-9900 scores 1687 against 1392 for the i7-6900K, a 21.2% advantage. In Cinebench R23 single-core, the i9-9900 leads 1907 to 1756, an 8.6% advantage.

Q: Do both processors have the same number of cores and threads?

A: Yes, both have 8 cores and 16 threads.

Q: Which processor has more memory bandwidth?

A: The i7-6900K has a quad-channel memory bus with 76.8 GB/s of bandwidth, while the i9-9900 has a dual-channel bus with 42.7 GB/s.

Q: Does either processor include integrated graphics?

A: Only the i9-9900 includes integrated graphics, specifically UHD Graphics 630. The i7-6900K has no integrated graphics.

Specification Differences

The two processors differ in the following recorded specifications:

• Base clock: 3.10 GHz for the i9-9900, 3.20 GHz for the i7-6900K.
• Boost clock: 5.00 GHz for the i9-9900, 3.70 GHz for the i7-6900K.
• TDP: 65 W for the i9-9900, 140 W for the i7-6900K.
• Socket: Intel Socket 1151 for the i9-9900, Intel Socket 2011-3 for the i7-6900K.
• Architecture: Coffee Lake (Coffee Lake-R) for the i9-9900, Broadwell (Broadwell-E) for the i7-6900K.
• Generation: Core i9 (Coffee Lake Refresh) for the i9-9900, Core i7 (Broadwell-E) for the i7-6900K.
• Die size: 180.3 mm² for the i9-9900, 246 mm² for the i7-6900K.
• Transistors: 3,400 million for the i7-6900K; not recorded for the i9-9900.
• L3 cache: 16 MB (shared) for the i9-9900, 20 MB (shared) for the i7-6900K.
• Memory bus: Dual-channel for the i9-9900, quad-channel for the i7-6900K.
• Memory bandwidth: 42.7 GB/s for the i9-9900, 76.8 GB/s for the i7-6900K.
• PCIe: Gen 3, 16 lanes (CPU only) for the i9-9900, Gen 3, 40 lanes (CPU only) for the i7-6900K.
• Integrated graphics: UHD Graphics 630 for the i9-9900, none for the i7-6900K.
• Multiplier: Locked for the i9-9900, unlocked for the i7-6900K.
• Release date: 2019-04-22 for the i9-9900, 2016-05-30 for the i7-6900K.
• Launch MSRP: $423 for the i9-9900, $1089 for the i7-6900K.
• Part number: SRG18 for the i9-9900, SR2PB for the i7-6900K.

Both share the same process node (14 nm), foundry (Intel), memory type (DDR4), L1 cache (64 KB per core), L2 cache (256 KB per core), lack of ECC support, desktop market segment, end-of-life production status, and 8-core/16-thread configuration.