Intel Core i7-7820X Skylake-X Review
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Page 1:Features & Specifications
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Page 2:Test Setup & Overclocking
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Page 3:VRMark, 3DMark & AotS: Escalation
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Page 4:Civilization VI & Battlefield 1
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Page 5:Grand Theft Auto V, Hitman & Shadow of Mordor
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Page 6:Project CARS & Rise of the Tomb Raider
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Page 7:Workstation & HPC Performance
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Page 8:Power Consumption & Thermals
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Page 9:Final Analysis
Power Consumption & Thermals
Intel isn't using a soldered integrated heat spreader (IHS) for Skylake-X or Kaby Lake-X. Instead of the solder most enthusiasts clamor for, heat moves from the die to the IHS through thermal paste. This decision has implications for both our power consumption measurements and overclocking efforts, as you no doubt saw in our Skylake-X Mess Explored: Thermal Paste And Runaway Power article.
We measure power consumption after the voltage converters and CPU, using points on the motherboard.
Power Consumption
These numbers are generated using stock motherboard settings; any significant under-volting has no effect, except to cause stability problems.
Core i7-7820X consumes significantly less power at idle than Broadwell-E, and it also provides a small benefit compared to the ten-core Core i9-7900X.
AMD's Ryzen processors use quite a bit more power during idle, and that doesn't change much between the eight- and six-core models. Its Zeppelin die is a unified four-core building block, so it makes sense that AMD still feeds the disabled silicon with power.
AutoCAD is lightly threaded, but even mundane workloads trigger Skylake-X's aggressive Turbo Boost frequencies. Less than one watt separates the Core i7-7820X and i9-7900X. Meanwhile, the previous-gen Core i7-6900K doesn't hit the same clock rates, conveying a slightly lower power figure.
The Ryzen models are in a class of their own, though we have to point out that they (along with Core i7-6900K) underperform Skylake-X. So, our power measurements aren't indicative of overall efficiency.
The Skylake-X processors draw more power than competing CPUs during our Metro Last Light gaming loop. We do observe a ~6W reduction going from Core i9-7900X to Core i7-7820X, though. Surprisingly, the -6900K is the most frugal Intel processor in the group.
Kicking off a Prime95 run unleashes the Core i9-7900X's hideous power consumption. Core i7-7820X is a little more civil, likely due to its disabled FMA units. But it still draws a lot more power than the Broadwell-E-based -6900K or Ryzen 7s.
Thermal Performance
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Thermal output was recorded during AIDA and Prime95 stress tests at stock frequencies. We used the Corsair H100i v2 cooler, which provided enough headroom to keep up with these CPUs.
As expected, we observe a slightly lower average temperature from Core i7-7820X compared to Core i9-7900X.
Speaking of, the Core i9-7900X encountered difficulties during the Prime95 AVX workload. We use AIDA's system stability test window to monitor temperatures during our test run, and it detected thermal throttling. Typically, AIDA provides a percentage to quantify the severity, though we don't know what caused the slow-down.
The system generates bit-coded throttling flags based on three variables: Tcore, Tpackage, and VRM temperatures. AIDA detects these flags, but doesn't specify which one the warning is based on. We suspect the VRMs are to blame in this case.
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The processor is selling for $420 or less. Heck I bought mine yesterday from Fry's for $393
Not to mention the fact that you can find the 1700 for even less, and more than likely be able to bump the clocks to atleast match the 1800x. Microcenter was selling them for 269.99 last week.
Perhaps full blown profesionals who need something a bit better than what Ryzen has right now but can go for an i9 would appreciate this, but even hen he/she/it would probably wait to see what threadripper had to offer.
"However, you do have to tolerate a "mere" 28 lanes of PCIe 3.0. Last generation, Core i7-6850K in roughly the same price range gave you 40 lanes, so we consider the drop to 28 a regression. Granted, AMD only exposes 16 lanes with Ryzen 7, so Intel does end the PCIe comparison ahead."
Doesn't Ryzen have 24 lanes? Still under intel but I'm pretty sure there's more than 16 lanes.
Ryzen does have 24 lanes, but only 16 are usable, 8 are dedicated to chipset and storage needs.
16X are available for graphics as 1x16 or 2x8.
4X dedicated for M.2
4X for the chipset that's split into 8x PCI-E v2 by the X370 and allocated dynamically IIRC
I actually do have work application which can utilize the multi-core.
will take em a couple quarters to figure out what to do. but i'm loving the price/performance amd has brought to the table and know intel will have no choice but to cut prices.
this is always good for the buyers
I agree they should have completed the power consumption testing on the OC'ed chips from AMD and Intel. What I don't agree with is the bias, did you read the summary?
When I read the 7900k review, I was really disappointed with Skylake X. Today's chip seems to make a lot more sense. It performs nearly as well as the 7900k in many situations. It eats less power. Generates less heat. Is priced more competitively. Typically beats the Ryzen 1800x in most situations also.
If money wasn't a concern, I would say Intel's 7820x is a better CPU than AMD's 1800x. It's a different story when you look at the price tags though.
Putting the 7700k in the benchmarks was a really interesting choice. It holds up well in a lot of situations despite having half the cores. The price is right too. Kaby Lake is still VERY relevant even in the HEDT realm.
You guys are conscious that you are doing benches for not even 1% of the users?
If you want to do 1080p benches so much, use 480/580 1050/1060.
TH: "But we want to avoid CPU bottleneck in a world that you cannot avoid it anymore... so we can show how insignificant our benches are!"
Me: "I want to know what this system can do compared to others at ALL popular resolutions so I can make my choice when it comes to my hardware and not slam a fanboy war over pointless rethorics."
Perhaps you missed this line in the conclusion.
Seeketh, and yee shall findeth. While these benches do not reflect the 7820x in Tom's review, it does show where the 7700K stacks up against the 1800x shown on Tom's for extrapolation:
http://images.anandtech.com/graphs/graph11549/87722.png
http://images.anandtech.com/graphs/graph11549/87692.png
http://images.anandtech.com/graphs/graph11549/87716.png
http://images.anandtech.com/graphs/graph11549/87686.png
Actually, you have it wrong. They want to avoid GPU bottlenecks when they test a CPU. At 4K resolutions, there are maybe a handful of games where a GTX 1080Ti or the latest Titan X won't stagger & fall on the ground in despair, & you'd see very little difference in performance between an old Phenom II X3 CPU & an i7-7700K, let alone between the most recent Ryzen CPUs & these Kaby Lake-X CPUs.
At 1080p resolutions, however, a GTX 1080Ti is going to yawn & only has to idle along at maybe 30-40% utilization on Ultra settings...which means the primary bottleneck will be with the CPU. Hence why CPU testing is performed at 1080p resolutions with the best available GPU at that moment (or sometimes the 2nd-best, depending on what's available).
I think redgarl is just expecting something else and that's why they're disappointed.
Agreed. We also get lots of complaints that we don't test CPUs @ 4k, but....relevance. Due to time constraints, we want our results to be applicable to as many people as possible. Here's a good idea of what is relevant.
Going by Steam's metrics, 3840X2160 is applicable to 0.86% of users. Granted, those are likely HEDT guys/gals.
According to Steam, 93.34% of gamers are at 1920x1080 or below.
2.19% are at 2560X1440.
So, 1920x1080 is relevant. And since we are testing CPUs, we test with the most powerful GPU available to reduce bottlenecks on components that aren't under review.
http://store.steampowered.com/hwsurvey/
Wouldn't be the first time either from that individual being snarky.
It is such a pet peeve of mine seeing people complain "well why not use realistic GPUs and resolutions people game with" and other nonsense. I've been on Tom's, Anandtech, and other hardware sites since the late '90s and it is not anything new to be testing CPUs in gaming benchmarks at below-optimal GPU resolutions (and over 90% of Steam gamers run 1080p or lower resolution monitors).
What they also fail to understand is that quite a few 1080p gamers are running 144-165Hz monitors where high end cards make a difference. But back to historic reviews, case in point, a 2010 flashback review of an i7 950 using a 1680x1050 gaming resolution with a high end HD 5870 GPU:
https://www.bit-tech.net/reviews/tech/cpus/intel-core-i7-950-review/6/
Why people still do not understand the logic behind ^^this I will never understand.
I hate the excuse that 1080p is more relevant when only .47% have this type of chip.
http://store.steampowered.com/hwsurvey/
Well I'm quite fond of that excuse so it looks like we're at an impasse.
Now back to the article... everyone is comparing Ryzen's platform with X299, and highlighting that X299 has better connectivity, more PCI-E leaves, etc. Fewer PCI-E lanes is not a disadvantage of Ryzen, as it is meant for a different market than Intel's HEDT platform. Ryzen should be compared to Intel's LGA1151 platform in that respect.
Threadripper and X399 will be X299's contender. You mention the cheaper Threadripper will be $800 vs $600 of i7-7820X, and that they are not direct competitors, but CPU cost is just a portion of the system cost. X299 motherboards are very expensive. X399 boards will probably be $100-$150 cheaper, offsetting that $200 CPU price difference.
But also comparing 8 core to 8 core CPUs is an interesting read. I'm surprised how well Ryzen holds up in some tests, even beating the HEDT Intel's.
All in all, the i7-7820X is a much better value than the i9-7900X, but for gaming the i7-7700K is still king.