Intel Core i9-7980XE And Core i9-7960X Review: Intel Attacks AMD Threadripper

Intel Core i9-7980XE And i9-7960X - Overclocking And Power Consumption

We also spent some time overclocking our Core i9-7980XE and Core i9-7960X processors using the Gigabyte Aorus X299 Gaming 3 motherboard. Like most of Intel's processors post Sandy Bridge, the easiest way to overclock Skylake-X is by tweaking various multipliers. BCLK straps and granular frequency manipulation are also available for fine tuning, but the quickest gains will come by simply upping the CPU core voltage and cranking up the CPU's multiplier. Like more mainstream K series SKUs, the Core X series processors are fully unlocked; so CPU, Turbo, and Memory frequencies can be easily altered through multiplier manipulation.
Overclocking The Core i9-7980XE and i9-7960X
Pushing Them To The Limit

With chips as large and complex as the Intel Core i9-7980XE and 7960X, power and cooling considerations are very important when overclocking. In their stock configuration, both of these processors are rated for 165W, but power consumption and heat output can shoot up considerably when the chip is pushed well beyond spec. As such, Intel has incorporated options to increase voltages and specify peak current thresholds too. The threshold options and power/heat considerations add some wrinkles and complexity to the overclocking process, if you're looking to squeeze every last MHz out of a Skylake-X chip, but we still found overclocking it to be relatively easy and fruitful, even with a mainstream, tower-type air cooler.

With proper cooling and a moderate voltage bump in the 1.35V range, we suspect many Core i9-7980XE processors will be able to hit 4.1 - 4.3GHz with quality air or liquid cooling. With more powerful cooling and some additional voltage though, we're certain higher clocks will be possible. Although the options are there to disable SpeedStep and various C states, overclocking Skylake-X is really as easy as finding the right combo of voltage, BCLK, and peak Turbo frequencies. By altering those options and leaving SpeedStep, etc. enabled, the processor can still clock-down when not under load, minimizing total power consumption and heat output when the CPU isn’t being fully utilized.

7960 oc

7980 oc
Overclocking In Action, Core i9-7960X (Top), Core i9-7980XE (Bottom)

We were able to take our particular Core i9-7980XE up to 4.1GHz all-core boost frequency using 1.35V and a peak, all-core turbo multiplier of 41. At that speed, however, we were pushing the limits of the platform as temperatures would spike above 90ºC, and invoking a multi-threaded benchmark that whacked every core would cause a system shutdown. Surprisingly, Our Core i9-7960X wasn't quite as overclock friendly. With fewer cores to power and cool down, we thought we'd get even higher frequencies out of our 7960X, but it wasn't fully stable at 4GHz, so we had to settle on an all-core max turbo clock of 3.9GHz, again with 1.35V.

oc cine
oc physics

While we had our Core i9-7980XE and Core i9-7960X processors overclocked, we re-ran a few benchmarks and saw some significant performance gains. The Core i9-7980XE's performance in Cinebench just misses the 4000 point mark and the Core i9-7960X is able to overtake the stock Core i9-7980XE result. The 3DMark Physics benchmark showed big gains as well, with the overclocked processors finishing in the top two slots.

Total System Power Consumption
Tested at the Outlet

Before wrapping things up, we'd also like to talk a bit about power consumption. Throughout all of our benchmarking and testing, we monitored how much power our test systems were consuming with a power meter to compare and contrast the results. Our goal was to give you an idea as to how much power each configuration used while idling at the Windows desktop and while under a heavy CPU workload. Keep in mind, this is total system power consumption being measured at the outlet with only the processor loaded and not the the individual power of the CPUs alone.

power 1

These power consumption numbers are somewhat shocking. Though the Core i9-7980XE and Core i9-7960X have 60 - 80% more cores than the Core i9-7900X (18 and 16 cores vs. 10 cores), they consumed only 27 - 28 more watts under load, and they used less idle power as well. After reviewing the Core i9-7900X, we thought the additional cores on the higher-end Core X-series processors would push power consumption much higher, and potentially surpass Threadripper, but that was not the case.

We pinged Intel to see if there was aggressive binning used when choosing dies for the high-end, many-core Core X-Series processors, but haven't gotten an answer just yet. 

power 2

We also monitored power consumption while overclocked to see how power was affected by the additional boost in frequency and saw some big jumps. Under load, the overclocked Core i9-7980XE-based rig pulled over 400 watts from the wall and the Core i9-7960X wasn't too far behind.  If you're contemplating buying one of these processors and are planning to overclock, make sure to take power and cooling considerations seriously.

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