Intel Core i7 3980X Extreme Edition Processor review

Photo of Intel Core i7 3980X Extreme Edition Processor

The Core i7 900 series has acted as Intel’s premier product range for over three year now, with the platform culminating in the six-cored 990X Extreme Edition. This architecture’s replacement is finally upon us, and as you would hope from Intel’s new flagship, there are plenty of improvements to talk about. The product launch of the new i7 3900 series consists of two SKUs, the 3930K and the 3960X, with more variants to be added over time. The former is a fully unlocked part clocked at a default frequency of 3.2GHz. The latter, which we are looking at today, is 100MHz quicker and has an extra 3MB of L3 cache to boot. Both have an impressive six cores under the bonnet. 

As with the socket 1155 Sandy Bridge processors, the 3960X has the capability to increase its clock frequency using Intel’s Turbo Boost technology. When one or two cores are under use the chip can reach a peak of 3.9GHz, whilst with 5-6 cores the extra speed drops to a still-respectable 3.6GHz. This is, of course, subject to the thermal conditions of the chip being favourable. 

Along with these new chips Intel has released a new chipset in the form of its X79. One of the main upgrades of this chipset is the addition of native 6Gb/s SATA ports, which are an evolution of those found on the mainstream P67 and Z68 boards. It’s disappointing there are only two of these on such an expensive product, but board partners will undoubtedly add more via 3rd party controllers. A lack of native USB 3.0 also seems like a missed opportunity. 

In terms of performance the 3960X excels, delivering performance 12% faster in our overall system performance benchmark compared to the i7 2600K – the previous record holder. It particularly excelled in the multitasking subsection, with an impressive 23% boost compared to the socket 1155 chip. Gamers will see little or no benefit from this new platform, however, with our F1 2011 and Crysis benchmarks showing results within 1% of previously released mainstream solutions. As usual, if you want the best gaming performance, prioritise the investment in your video card rather than the CPU. 

Where the 3960X really excels is in its memory bandwidth. X58 featured a ludicrously powerful triple channel memory setup and X79 goes one stage further, offering quad channel DDR3 RAM support and a peak measured memory bandwidth in Sisoft Sandra of over 40GB/s. This is a monumental step up from socket 1155 based machines; it’s just a shame this doesn’t translate into direct real-world performance in many benchmarks. 

Overclocking wise, we managed to take our sample chip to a maximum stable frequency of 4.7GHz. Any higher and the system would blue screen after around 20 minutes of stress testing. Keeping the i7 3960X cool is extremely challenging as you will need plenty of extra voltage for the best clock speeds. Even our Corsair H100 water cooler was close to its limit at 4.7GHz, as were the VRMs on the motherboard which became red hot when running Prime 95. The resulting performance was well worth it however, with the 3960X delivering benchmark results higher than any other single CPU system we have reviewed. 

Company: Intel


  • Super fast, overclockable
  • Quite expensive


The thorn in the Core i7 3960X's side is a predictable one; its price tag. At £840 including VAT for the chip and at least £180 for a decent board to run it in, the platform cost of such a rig is prohibitive. The 3960X may be the fastest desktop processor in the world, but the 3930X is a much more affordable stepping stone onto Intel's new flagship platform and you won't need to sell a kidney to afford it.