Intel Core i9-7900X Skylake-X

Intel Core i9-7900X Skylake-X 10 Core CPU Review

Since the introduction of AMD’s Zen CPU architecture to the market, communities, consumers and media outlets have been abuzz from all of the hype; not just the hype prior to the launch, but of course performance upon release too. It’s been no surprise that AMD’s Ryzen processor launch has been a success due to the price/performance ratio of their processors, more impressively the Ryzen 7 range with the 1700 being one of the top core/performance/price effective processors of the last 5 or 6 years. The big question from most people however was “how are Intel going to respond?”. Well Intel made their response well known from the outset and decided to bring forward the launch of their latest HEDT platform based on the X299 chipset, with the processors being codenamed ‘Skylake-X’…


Today we have one of those processors, but more specifically, the Intel Core i9-7900X which features 10 cores and 20 threads at a TDP rating of 140W. This processor also features 13.75MB of restacked L2 cache and utilises Intel’s Turbo Boost 3.0 technology. The Core i9-7900X processor features a base frequency of 3.3GHz and a maximum turbo boost frequency of 4.3GHz; this is fantastic for a 10-core processor and overshadows the AMD’s Ryzen 7 1800X processors boost of 4.0GHz by 300MHz. Let’s take a look at the technical specifications of the processor and dive right into the review…

Intel Core i9-7900X Specifications & Features

  • Interface
    LGA 2066
  • Cores/Threads
  • TDP
  • Base Frequency
    3.3 GHz
  • Turbo Frequency
    4.3 GHz
  • L3 Cache
  • Graphics
  • Graphics Base/Turbo
  • Memory Support
  • Memory Contoller
    Quad Channel
  • Unlocked Multiplier
  • PCIe Lanes

As we can see from a rundown of the main specifications the Core i9-7900X sits with quad channel memory support and shares similar specifications to Intel’s previous 10 core processor, the Core i7-6950X. The main improvements have come in the way of a faster clock speed, as well as a lower entry price onto the market ($1723 vs $1000). This is fantastic as far as Intel are concerned and have clearly decided to adopt a more aggressive pricing structure; although AMD haven’t given them any choice and it goes against Intel meaning they could have been more wallet friendly, but opted not to be.


In terms of new features, Intel have increase their supported DDR4-2400 rating to DDR4-2666 on all of the new Skylake-X processors with the exception of the Core i7-7800X processor. The Core i9-7900X also has had a bump in PCI lanes to 44 meaning multi graphics card setups and those favouring NVME PCI storage drives have plenty of lanes to pull from; we won’t even mention Kaby Lake X and their 16 PCI lanes, aside from this mention obviously! Other features include Intel’s VROC support meaning that you can unify up to 20 SSDs into a singular bootable RAID volume, as well as ratio offset control for the new AVX-512 vectorisation instruction set; this is something AMDs Zen architecture doesn’t support and makes Intel a clear choice for those users utilising vectorisation into their workloads.

Test Setup & Methodology

Test Setup

Memory – Crucial Ballistix Elite 3000 MHz (4x8GB) DDR4
Graphics – ASUS GTX 1060 STRIX 6GB
Cooler – be quiet! Silent Loop 240mm
PSU – be quiet! 1000w Dark Power Pro 11
Storage – Crucial MX300 525GB SSD
OS – Windows 10 Professional 64bit

Testing Methodology

2D Synthetic Benchmarks: AIDA64, Cinebench R15, PCMark 8
3D Synthetic Benchmarks: 
3DMark Fire Strike, 3DMark Time Spy
Gaming Benchmarks: 
Ashes of The Singularity, Thief, Tom Clancy’s: The Division, Total War: WARHAMMER (1080p/1440p/4K)

When running the above benchmarks, the processor and all major settings on the motherboard have been left at default to coincide with every other processor tested. This is to keep fair and consistent results to omit gains given from overclocked results. Each processor has had turbo left on, but has been left to run of its own accord.

Intel Core i9-7900X Skylake-X Processor Benchmark Results

(2D Synthetic) AIDA64

AIDA64 CPU Queen 7900X Performance

AIDA64 CPU AES 7900X Performance

AIDA64 CPU Photoworxx 7900X Performance

AIDA64 Memory Read 7900X Performance

AIDA64 Memory Write 7900X Performance

AIDA64 Memory Copy 7900X Performance

(2D Synthetic) Cinebench R15

Cinebench R15 CPU 7900X

Cinebench R15 OpenGL 7900X

(2D Synthetic) PCMark 8

PCMark 8 7900X

(3D Synthetic) 3DMark

3DMark Fire Strike 7900X Performance

3DMark Time Spy 7900X Performance

(Gaming) Ashes Of The Singularity

AOTS 1440p 7900X

(Gaming) Thief

Thief 1440p 7900X

(Gaming) Tom Clancy’s: The Division

The Division 1440p 7900X

(Gaming) Total War: WARHAMMER

Total War WARHAMMER 1440p 7900X

Performance Analysis & Conclusion

When you compare Intel’s new flagship 10 core Skylake-X processor (the Core i9-7900X) against Intel’s previous iteration in the shape of the Broadwell Core i7-6950X, on paper everything looks in the Core i9-7900X’s favour. Intel has been developing new and more efficient ways in producing HCC (high core count) processors for at least the last 10 years and they have done a fantastic job of it; some would say they are the authority on HCC processors.

Back in September 2014, Intel launched their Haswell range of processors which featured FIVR (fully integrated voltage regulation) and proved a more efficient way of streamlining power through to the processor and all of its components. This time round, Intel have gone from a 22nm manufacturing process, all the way down to 14nm and although the way they have designed it is albeit similar, the Skylake-X Core i9-7900X actually features a new ‘Mesh’ design which allocates cache in a different way than Intel have done before on the desktop platform. The results of this speak for themselves, but let’s digest it and see what’s what shall we…

Design & Performance

Intel’s new integrated voltage regulator and mesh design have clearly had an impact on performance, mostly positive, but some quite negative results too! One large improvement jumping from the different architectures is the increase in overall performance at stock of both the Core i7-6950X and Core i9-7900X processors; with the latter being the winner in synthetic performance via our benchmarking suite. Although somewhat of a rushed-out platform thanks to AMD’s high core/low cost offerings (Ryzen), this played Intel’s HEDT hand a little earlier than expected and even though Intel’s architectures are usually designed well in advance of launch, something seemed a little off with X299 from the offset. The chipset itself is brilliant in my opinion, but maybe a little more could have been done at launch to ensure performance was hard hitting; we re-tested from previous CPU reviews to give a more up-to-date and fair review for the benefit of yourselves, consumers and of course, window shoppers who would do anything for a 10-core processor for bragging rights.

The somewhat negative side is down to out and out gaming performance; aside from in Ashes of The Singularity, the Intel Core i9-7900X performed the worst out of all the processors in our testing when gaming, even the Core i3-7350K. Now I know what you’re thinking, it’s a 10-core processor and isn’t optimised for gaming… but the same was said about Ryzen 7 and it’s hard to ignore the difference in results between the predecessor and the new kid on the block (Core i7-6950X v i9-7900X again). So, what do I put the issue down to? Well the main change of course is the mesh design on the cache and on ambient cooling (AIO), I struggled to get about 3.8GHz on the cache, even though the core clock overclocked on my sample to 4.5GHz with relative ease; albeit with thermal throttling issues. Was the new design rushed, or is it simply a case of lack of gaming optimisation? Who knows, but it’s certainly not looking good for gamers looking for a new processor and out of the ones we have tested, I would still have to recommend the Intel Core i7-7700K for maximum performance whilst gaming.


This is where the Intel Core i9-7900X looks great on paper compared to the Core i7-6950X; it’s around $600-700 cheaper at its launch. This can be attributed and credited to AMD’s Ryzen launched and more specifically, the success AMD have had since the launch of Ryzen 7 in the 8-core segment of the market. It’s no surprise the 7900X outperforms the Ryzen 7 range in 2D synthetic benchmarks and even manages to clock quite a bit higher, which is another reason this processor does so well.

Final Thoughts

If you’re looking for a new processor and require AVX-512 vectorisation support, do a lot of video/photo editing, content creating, streaming or you have £900/$1000 to blow on a 10-core processor you probably won’t get a better overall CPU than the Core i9-7900X. The flip side here and number cruncher is the gaming performance. If you’re more into gaming than any of the above and don’t intend to utilise all of the 44 PCI lanes with super multi-graphics configurations, the Intel Core i7-7700K offers much better gaming/price performance than virtually anything currently on the market.

Huge thanks to Intel for sending a sample of the Core i9-7900X in for review!

Play3r Gold Award

  • Performance
  • Design
  • Value


– Fantastic 2D performance
– Much cheaper and newer alternative to the Core i7-6950X ($999 v $1700)
– Features 44 PCI lanes for beastly multi-graphics card setups
– High clock speeds out of the box with Intel Turbo Boost 2.0 (4.3GHz turbo)
– New king of 10-core HEDT platform


– Gaming performance is very concerning from a $1000 processor, HEDT focused or not

User Review
0 (0 votes)
Comments Rating 0 (0 reviews)
Previous articleID-Cooling Frostflow+ 280 AIO Cooler Review
Next articleOverclockers UK Introduce New Hydra Brand Products

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.