Intel Core i7 3960X

Intel’s CPU Range

Intel Core i7 Series 3000 processors were launched in November 2011.

The i7 3960X is the first of these six-core processors to hit the market and comes complete with Turbo mode and Hyper-Threading technology.

Based on the Sandy Bridge architecture, these Sandy Bridge-E processors use a 2011 socket (X79 chipset) and have 10 to 15 MB of L3 cache.

These CPUs use 1600 MHz DDR3 quad-channel memory. Note that they have the same 32 nm process node and 130-watt thermal design power (TDP) as Intel's previous generation of CPUs.

The Intel Core i7 3960X is the first model to emerge from Intel’s top-of-the-range Sandy Bridge-E CPU series. It’s an exceptional product with six cores, a Turbo mode, Hyper-Threading technology and a lunch price pushing £1,000! Based on the firm's Sandy Bridge architecture, this new power-packed processor re-affirms Intel’s role as undisputed leader of the consumer CPU market.

It seems like Intel has taken everything it does best and packed it into the Core i7 3960X. For starters, the processor uses the excellent Sandy Bridge architecture, already seen in the likes of the Core i7 2600K and i5 2500K. This new CPU has a 32 nm design just like Intel’s previous generation of processors (the Core i7 980X in particular), but this beast is packed with 2.27 billion transistors. Plus, it's been designed to optimise power consumption and maximise processing efficiency.

Turbo Mode, Hyper-Threading, Quad-Channel Memory

This processor is brimming with all of Intel's latest technology, including features like a Turbo mode and Hyper-Threading. For a more detailed explanation of how they work, see our review of the Core i7 2600K. Basically though, Turbo mode (here it’s version 2.0) cranks up the clock speed by 300 MHz or 600 MHz depending on how many cores are actually in use at any one time.
 

Turbo mode as explained by Intel. Click to enlarge.

That can help speed things up in ‘single-thread’ apps which don’t make use of the processor’s multiple cores. In this particular CPU, the base frequency is 3.3 GHz but this can be pushed up to 3.9 GHz in the right conditions.
 

Hyper-Threading allows the CPU to artificially double the number of cores the operating system ‘thinks’ it has. So instead of the six physical cores in the Core i7 3960X, the system would think it had 12 cores. This allows processing to be more effectively distributed among the various cores for increased efficiency.
 

Intel has also opted for a quad-channel memory controller, rather than the dual-channel system previously used. In theory then, you’re better off using memory modules in multiples of four if you want to ensure maximum performances. In practice, however, the ‘loss’ in performance from using two memory modules is actually negligible, as out test results show:
 

Results in seconds except for Cubase 5.1 (compressors on) and HQ games (frames per second).

Power Consumption

As promised by Intel, power use is controlled more effectively than in previous-generation CPUs. When idle, the Core i7 3960X uses around 10 watts less power than previous-generation models, drawing a total of 97 watts in our test computer. That’s a little better than the AMD FX-8150, but it’s still a fair way off Intel’s four-core Sandy Bridge CPUs, some of which pushed power use down below 85 watts.
 

When working intensively, there’s a very slight drop in power use compared with previous models, as the Core i7 3960X clocks up 252 watts, next to 255 watts for the Core i7 980X and 262 watts for the AMD FX-8150. While these results are still pretty high, they're actually not that bad given the monster performance levels.

Performance: Applications

Intel already reigned supreme with the fastest CPUs on the market with the Core i7 980X and i7 990X. It’s therefore not too much of a surprise to see that this new processor is even faster still (22 %), further increasing Intel’s lead over AMD. Note though, that this Core i7 3960X processor sells for the best part of £1,000, while AMD’s top-end processors are more affordable.
 

Click on the graph to see all our test results
and compare CPUs in the Face-Off.

All in all, at the time of writing, the Core i7 3960X is the fastest processor on the market for users willing to splash some cash.

Performance: Games

While the older Core i7 980X was still fastest for performance in applications, it was outstripped in games by Sandy Bridge processors like the Core i7 2600K and Core i5 2500K. Since the i7 3960X also uses the Sandy Bridge architecture, it’s no surprise to see performances of a similar level to the other models in the range. This makes it one of the best CPUs for gaming currently available, although some of Intel's less high-end Sandy Bridge models do just as good a job.