Studying the effect of frequency and timing for Coffee

Subject: Memory | October 18, 2017 - 04:20 PM |
Tagged: coffee lake, i7 8700k, Intel

The performance of AMD's Ryzen chips depend heavily on the frequency of the RAM installed thanks to how Infinity Fabric works.  TechPowerUp decided to see how sensitive Intel's Coffee Lake processors are, testing the performance with RAM speeds from 2133MHz up to 4000MHz as well as modifying the timings.  Not to spoil the results for you, we can reveal something else their tests revealed, G.SKILL's Trident Z DDR4-3866 16GB kit is impressively flexible, they were stable at 15 different combinations of timings and frequencies.  Check out the full results to discover the sweet spot.

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"We take a close look at memory speeds, latencies and command rate on Intel's latest Core i7-8700K with Z370. Scenarios tested include fail-safe 2133 MHz, the platform default of 2666 MHz and overclocked memory speeds from 3000 MHz to 4000 MHz - at various timings."

Here are some more Memory articles from around the web:

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Source: TechPowerUp

How hot is your Coffee?

Subject: Processors | October 10, 2017 - 06:35 PM |
Tagged: Intel, coffee lake, i7 8700k

The Tech Report addresses two questions about Intel's i7-8700K in their latest review, how to keep it running cool and how the multi-core enhancement feature changes that answer.  Multi-core enhancement is a BIOS level overclocking feature which allows all cores on Coffee Lake processors to hit the full boost clock instead of only a single core.  In this example, a single core could hit 4.7 GHz while the other cores are being limited to 4.3GHz, however with multi-core enhancement enabled that limit is removed and all cores can hit 4.7GHz simultaneously.  As with any type of overclock this produces significantly more heat and requires more cooling.

This enhancement means there are two answers to the question about cooling your Coffee.  With the enhancement feature disabled you should be just fine with a CM Hyper 212 Evo or equivalent heatsink, however with MCE enabled even a Corsair H115i shows a 90° C package temperature with core temps between 84-90C.  Keep this in mind when shopping for parts; it is nice to have all cores running at their full Boost Clock but you will need to be able to cool them or else see throttling as the chip sense Tjunction temps in excess of 100C.

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"Intel's Core i7-8700K proved an exceptionally well-rounded chip in our testing, but the company's choice of thermal interface material has left many wondering whether the Coffee Lake flagship will prove a challenge to keep cool. We establish a handy baseline for what might make a chip "difficult" to cool and see whether the Core i7-8700K falls on the wrong side of the line."

Here are some more Processor articles from around the web:

Processors

 

Extreme Overclockers Fill Coffee Lake With Liquid Nitrogen

Subject: Processors | October 6, 2017 - 11:44 PM |
Tagged: Extreme Overclocking Competition, overclocking, liquid nitrogen, coffee lake, i7 8700k

A new CPU means new overclocking challenges and with it comes a new batch of refreshed Z370 motherboards. At the high end, the current frequency record for the Core i7 8700K is 7,405.1 MHz obtained by Hovan Yang using a MSI Z370 Godlike Gaming motherboard.

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He’s not the only one testing the limits of Intel’s new six core processors though. Asus held an overclocking event a few weeks ago where renowned overclockers Alex@ro, elmor, der8auer, Rsannino, and shamino battled it out. Der8auer got a pre-release crack at the i7 8700K at the event and after de-lidding and replacing the TIM with liberal amounts of Kryonaut thermal paste managed to achieve 6.8 GHz using 1.8 volts and a 68x multiplier (and bumping the cache speed up to 6.3 GHz). With these settings on the monster Maximus X Apex motherboard, he scored 299 in single threaded and 2253 in multithreaded in Cinebench R15. Der8auer compared this benchmark result to Skylake X at 5.5 GHz scoring 237 in the single threaded test. Following the benchmark run, he went for the highest CPU-z validated clockspeed he could hit and managed to push the chip to 7300 MHz (100MHzx73). From there overclocker Alex from Romania was able to overclock his i7 8700K to 6844 MHz and scored 2306 in Cinebench R15.

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The overclockers broke 10 new records in the six core CPU category and also managed to break a DDR4 clockspeed record by pushing a single 8GB G.Skill DIMM to 5529.2 MHz at 24-31-31-63-3 timings!

Also of note is that Coffee Lake does not depend of FIVR so overclockers are able to use a full pot of liquid nitrogen (or liquid helium) to cool the processor down to much lower temperatures so that they can crank up the voltage and achieve much higher clockspeeds than Skylake-X which cannot boot if temperatures are too low.

While the ASUS team does not hold the clockspeed record anymore (though they might regain it with some Liquid Helium), der8auer has an interesting video and Asus has a blog post with photos talking about the process, setup, and everything that goes into these extreme overclocking sessions including pre-binning the chips, preparing the IHS and motherboard for the super cold (-185°C to -190°C) temperatures, and keeping the processors and motherboards running. For example, and Josh will be interested in this, part of the process of preparing the motherboard involves slathering it in Vaseline!

If you are interested in this extreme overclocking stuff it gives a bit of insight into all the fun to be had!

Source: Asus