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Intel Skylake / Kaby Lake

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Sweepr

Diamond Member
May 12, 2006
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Skylake-X & Kaby Lake-X Reviews List

- AnandTech (Core i7-7800X, Core i7-7820X, Core i9-7900X)
- Hardware Canucks (Core i7-7740K)
- The Tech Report (Core i9-7900X)
- Guru3D (Core i9-7900X)
- Tom's Hardware (Core i9-7900X)
- bit-tech (Core i9-7900X)
- Hexus (Core i9-7900X)
- PCGamesHardware.de (Core i9-7900X - Preview)
- PCWorld (Core i9-7900X)
- Overclock3D (Core i7-7820X, Core i9-7900X)
- HotHardware.com (Core i7-7740K, Core i9-7900X)
- LanOC Reviews (Core i7-7740K, Core i9-7900X)
- Hardware.info (Core i7-7740K, Core i9-7900X)
- PC Perspective ( Core i9-7900X)
- TweakTown (Core i9-7900X)
- GamersNexus (Core i9-7900X)
- 4Gamer.net (Core i9-7900X)
- Coolenjoy (Core i9-7900X)
- LinusTechTips (Core i9-7900X)
- Vortez (Core i7-7740K)
- Coolaler (Core i7-7740K, Core i9-7900X)
- PConline (Core i7-7820X)
- Mobile01 (Core i9-7900X)
- TechBang (Core i7-7820X, Core i9-7900X)
- 3DMGame (Core i7-7740K)
- 3DNews.ru (Core i9-7900X)
- Benchmark.pl (Core i7-7740K)
- Zol (Core i7-7740K, Core i7-7820X)
- XFastest (Core i9-7900X)
- PCGamer (Core i9-7900X)
- Techspot (Core i7-7800X, Core i7-7820X, Core i9-7900X)
- PurePC (Core i9-7900X)
- Hardware.fr (Core i7-7740K, Core i9-7900X)
- Hardwareluxx (Core i7-7740K, Core i7-7800X, Core i7-7820X, Core i9-7900X)
- PCLab (Core i7-7740K, Core i9-7900X)
- SweClockers (Core i9-7900X)
 
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Zucker2k

Golden Member
Feb 15, 2006
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This launch is a bit disappointing. The motherboard makers seem to have been caught with their pants down once again. The performance looks promising, but with the current news about a microcode (bios) update, I'm not sure who is testing what? Also, the lack of solder was extremely shortsighted. Anywho, I plan to run my chip delidded. Any delidded reviews out there? A cooler chip sucks less juice is the popular understanding.
 
Mar 10, 2006
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The rest of the Skylake-X SKUs are going to be less appealing to enthusiasts who want the best single thread performance and multithread performance. MCC die based 16C and 18C SKUs are likely to have serious difficulty with overclocking to 4 Ghz given 7900x is already drawing 150w at stock.
The rest of the Skylake-X SKUs will obviously be for multi-threaded workloads. If you want the best ST perf, get a 7700K or 7740K, or soon Coffee Lake.
 

lolfail9001

Golden Member
Sep 9, 2016
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The funny thing is that AVX-512 workloads will be a major pain to run on 7900X+, because now it sucks down ridiculous amounts of power and from what i see AVX offset does not allow to reduce voltage too. Ultimately it means that to run LinX stable CPU you need to settle for like 1.1V as your very max voltage on 7900X already.
 

Zucker2k

Golden Member
Feb 15, 2006
1,263
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The funny thing is that AVX-512 workloads will be a major pain to run on 7900X+, because now it sucks down ridiculous amounts of power and from what i see AVX offset does not allow to reduce voltage too. Ultimately it means that to run LinX stable CPU you need to settle for like 1.1V as your very max voltage on 7900X already.
I think anywhere from 3.8ghz to 4ghz is possible for that voltage in linx with reasonable temps.
 

lolfail9001

Golden Member
Sep 9, 2016
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I think anywhere from 3.8ghz to 4ghz is possible for that voltage in linx with reasonable temps.
Yeah, 3.8Ghz with near 100 degrees on D15S.
The problem is that for non-AVX workloads you are voltage limited. So you either settle for running ~4.5-4.7Ghz in non-AVX and like 2Ghz in linx or 3.8Ghz in every workload. Or 3.3Ghz in linx and 4.3Ghz in everyday usage. On 7900X.
 

inf64

Diamond Member
Mar 11, 2011
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Considering that while consuming 40% more power at the platform level, it does twice the job, it is reasonably efficient, ya know.
8C 7820X does twice the job of 1800X in what parallel universe please? Oh and OCed 1700 to ~3.9Ghz vs 4.5Ghz (realistic for 7820) is ~25% performance delta while total platform cost is in the range of +400$ without even a cooler factored in (used cheapest x299 board and DC ram instead of QC). Plus the furnace at 4.5Ghz would draw ~90W more than OCed 1700.
 
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lolfail9001

Golden Member
Sep 9, 2016
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8C 7820X does twice the job of 1800X in what parallel universe please?
In the AVX2 stress test universe. Actually sorry, not twice but twice times clock ratio.
Oh and OCed 1700 to ~3.9Ghz vs 4.5Ghz (realistic for 7820) is ~25% performance delta while total platform cost is in the range of +400$ without even a cooler factored in (used cheapest x299 board and DC ram instead of QC).
You could also complain that Bugatti Chiron costs 3-4 orders of magnitude more than second hand Corsa even though it is only like 3 times faster.
Plus the furnace at 4.5Ghz would draw ~90W more than OCed 1700.
While being faster. That said, you are correct, it is such a furnace that i would never consider getting it.
 

inf64

Diamond Member
Mar 11, 2011
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In the AVX2 stress test universe. Actually sorry, not twice but twice times clock ratio.

You could also complain that Bugatti Chiron costs 3-4 orders of magnitude more than second hand Corsa even though it is only like 3 times faster.

While being faster. That said, you are correct, it is such a furnace that i would never consider getting it.
Bad comparison since Ryzen would be just 25% slower in non-avx workloads (which is 99% of the cases) while costing 500 dollars less (cooler counted in) and heating the room less/costing less(unless you have free electricity). But sure, some people want the most expensive products which tend to have worst perf./$ ratios anyway. IMO this whole platform is a mess and not worth it at all.
 
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vissarix

Senior member
Jun 12, 2015
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An overclocked i7 7800x is enough to beat any ryzen on any workload and has the same price...The rest of the lineup from Intel is just competing with himself...
 

ManyThreads

Member
Mar 6, 2017
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Just ordered a 7820K and TUF MK1. Hope I did OK with the mobo choice, never owned anything from the TUF series before. Integrated fan makes me nervous, but 5 year warranty is good.
 
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Markfw

CPU Moderator, VC&G Moderator, Elite Member
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May 16, 2002
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An overclocked i7 7800x is enough to beat any ryzen on any workload and has the same price...The rest of the lineup from Intel is just competing with himself...
The Anandtech review (for one) shows the 1700 (cheaper at 299) beating the 7800 at many things. The 1700x beats it in almost everything. Your argument that OC'd it beats it is just a guess, and does not count the fact that its not at sustained loads. This post borders on trolling.
 

crisium

Platinum Member
Aug 19, 2001
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Maybe make a new thread so it becomes clear when Skylake-X Review discussion begins? 12,000 posts in?

Anyway, looking for OC results if anyone OCed the 7800X (7 core) at all.
 

Karnak

Senior member
Jan 5, 2017
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An overclocked i7 7800x is enough to beat any ryzen on any workload and has the same price...
Wrong and wrong. Not at stock and not overclocked.

The rest of the lineup from Intel is just competing with himself...
The rest of the lineup from Intel is in a lot of trouble if AMD launches a 16C Threadripper for less than $1000. Which is not that unlikely IMO.
 

Shivansps

Diamond Member
Sep 11, 2013
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You might want to share some of your technical knowledge with Ian:

"So this is surprising. Normally Intel are relatively good at their recommended TDP numbers: the ability to remove a certain amount of heat related to power consumption is something Intel either gets bang on, or has plenty of headroom. The sole Kaby Lake-X CPU that completed this test is an example: at under 60W, it is comfortably under the 112W TDP that chip has. But for the 140W Skylake-X parts, we recorded nearly 150W power consumption."
TDP stands for "thermal design power" there is no much to try to go around it. It cant be any clearer than that.
 

vissarix

Senior member
Jun 12, 2015
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The Anandtech review (for one) shows the 1700 (cheaper at 299) beating the 7800 at many things. The 1700x beats it in almost everything. Your argument that OC'd it beats it is just a guess, and does not count the fact that its not at sustained loads. This post borders on trolling.
You dont need to be a rocket scientist to realize that a 5ghz 6 core Skylake-X is faster then an 8 core 4ghz Ryzen...especially if you consider 10% higher Ipc for Skylake X...
 
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Malogeek

Golden Member
Mar 5, 2017
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yaktribe.org
The Anandtech review (for one) shows the 1700 (cheaper at 299) beating the 7800 at many things. The 1700x beats it in almost everything. Your argument that OC'd it beats it is just a guess, and does not count the fact that its not at sustained loads. This post borders on trolling.
Not to mention the 7800X drawing over twice as much power as the 1700.
 

tamz_msc

Platinum Member
Jan 5, 2017
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In the AVX2 stress test universe. Actually sorry, not twice but twice times clock ratio.
As if generating heat with Prime95 is a relevant workload...
You could also complain that Bugatti Chiron costs 3-4 orders of magnitude more than second hand Corsa even though it is only like 3 times faster.
I'd rather have a 911 GT3 with a manual transmission.
 

wildhorse2k

Member
May 12, 2017
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7740X will have very few customers as X299 boards are too expensive and offer the same features as Z270 with this CPU.

Anybody who considered the 7800X should look elsewhere. It has too big latencies and halved AVX-512. Better wait for Coffee lake or go with competition. Coffee lake should be an excellent overall CPU.

I guess many prospective 7820X customers will be let down by mediocre gaming performance, high latencies and halved AVX-512.

For 7900X customers mediocre gaming performance doesn't matter much as they are not bought primarily for gaming. As long as BIOSes get a bit more tuned and performance stays above Broadwell-E it will be fine. So for me 7900X is still the best option, but I will wait how it turns out to get a more stable platform and see if there are any serious bugs.

I see the 7900X at the breaking point - it should sell ok, also models above it but not models below it.

Performance could get better with DDR4 4000 and increased uncore frequency - base is just 2.4 and 2.8-3.0Ghz is definitely possible. Intel keeps it down for TDP reasons.
 
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formulav8

Diamond Member
Sep 18, 2000
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Well I looked at some reviews on the 7900x and the power consumption and temps are awful. And looks to be quite buggy.
 

Markfw

CPU Moderator, VC&G Moderator, Elite Member
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May 16, 2002
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You dont need to be a rocket scientist to realize that a 5ghz 6 core Skylake-X is faster then an 8 core 4ghz Ryzen...especially if you consider 10% higher Ipc for Skylake X...
I don't remember the exact review, but due to thermal problems, they said that 4.5 was the highest sustained they thought they could do. Also, Ryzen has 8 cores vs the 7800 is 6 cores. Again, you are just guessing. Knock it off.
 
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Shlong

Diamond Member
Mar 14, 2002
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7900X is 30% faster than R7 1800X, draws around 40% more power, and costs around 100% more. 7900X is very hard to overclock even with custom water loops unless you de-lid. If comparing with an R7 1700, even more advantages for Ryzen. Ryzen is looking pretty good for bang for the buck value now. Threadripper should be released in the near future and that should have Intel worried.
 

wildhorse2k

Member
May 12, 2017
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I don't remember the exact review, but due to thermal problems, they said that 4.5 was the highest sustained they thought they could do. Also, Ryzen has 8 cores vs the 7800 is 6 cores. Again, you are just guessing. Knock it off.
7820 can do 4.8Ghz, so I guess 7800X can do 5Ghz. https://www.overclock3d.net/reviews/cpu_mainboard/intel_core_i7_7820x_skylake_x_review/3
However the original post that OCed 7800X would beat any Ryzen is still a speculation as we don't have it benchmarked.

http://images.anandtech.com/graphs/graph11550/87080.png shows little difference between 7800X and 7900X power consumption though which looks very strange given the core difference. One would guess disabled cores would not consume power.
 
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lolfail9001

Golden Member
Sep 9, 2016
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As if generating heat with Prime95 is a relevant workload...
Generating heat was the workload in question, in case you missed context.
Bad comparison since Ryzen would be just 25% slower in non-avx workloads (which is 99% of the cases) while costing 500 dollars less (cooler counted in) and heating the room less/costing less(unless you have free electricity).
Ryzen would be just 25% slower in non-avx workloads while consuming 20% less power (maybe?). I think i know the winner.
 
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Topweasel

Diamond Member
Oct 19, 2000
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TDP stands for "thermal design power" there is no much to try to go around it. It cant be any clearer than that.
Intel has been using a "good enough" average power usage envelope that covers when a CPU starts to throttle away from boost for a long while. AMD getting tired of being compared to Intels not actual top power usage number tried to come up with an A(verage)DP power usage or something like that back in the Athlon X2 or Phenom days. AMD has since dropped that and just calls it TDP like Intel. Fact is neither number actually represents full/max power usage under load for their CPU's. Since both support thermal throttling, the TDP rating is more of a cooler recommendation rating than power rating.
 

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