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Intel Skylake / Kaby Lake

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wildhorse2k

Member
May 12, 2017
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I think the best chip for people who like to overclock from this year´s "generation" will be the 7920x, under condition it will come soldered. I would hazard a guess it could be OCable almost as high as 7900x (4,6+), cause only 2 more active cores, thanks to the possible solder not as difficult to cool, and overclocked on par with 1950x performance-wise (more or less, if 7900x can get ~2500 CB points at 4,5, then 7920x will no doubt attack 3000).

Granted, it will be slightly more expensive and less efficient/more power-hungry (but you never know, perhaps HCC dies will be for whatever reason superior in this regard to the LCCs, although i doubt it), but in regard to overclocking and top attainable clocks, probably way more fun than Threadripper.
I don't think 7920X will be a good choice at all for OC:
  • 7800X doesn't seem to consume that much less power than 7900X, as if those disabled cores couldn't be completely disabled. This would mean power consumption of 7920X won't be very good either.
  • 7900X has quite high L3 latency, almost as high as cross CCX of Ryzen. 7920X is expected to have the same latency like 7980X, which will be more than 7900X. You are buying just 2 extra cores with worse latency.
  • with practical upper limit of 7900X about 4.5Ghz (due to thermal issues), 7920X will be maybe 4.2Ghz for all core clock without delid
  • its questionable whether 12-18C will be delidable, they will have bigger die
  • at high clocks Skylake-X is inefficient, I'm not sure you want to have a case next to you with fans at maximum (even water cooling)
If you can afford the 7980X and OC it:
  • I think you will get better performance increase with OC, due to this CPU having lower frequency where it is more efficient. Increase of 100Mhz brings less heat increase (per core) than with 7920X. Percentage wise you will get more performance for each 100Mhz, due to base being lower.
  • use DDR4 4000 memory (instead of low latency 3600) to get good bandwidth as this CPU might be bandwidth starved (unlike its 6 channel Xeon brother)
  • you may even get better performance than Xeon 28C / Epyc 32C with extreme OC (as they both have low clocks and are locked)
  • you tune turbo 1-2 core frequency to be about 4.3Ghz (and downclock the rest, even below stock) and still may get ok performance for few thread applications

In my opinion the 2 most interesting X299 - CPUs are 7900X (high clocks, decent for gaming and work, can get performance like 12C) and 7980X (potentially crazy performance like Xeon 28C when OCed), but the price of 7980X playing against it.
 

wildhorse2k

Member
May 12, 2017
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- you mention delidding, my whole premise of 7920x being good chip for OCers was based on the possibility it would be soldered (as would the rest of HCC line-up) :)
- because of that (solder) there would be no thermal issues like with 7900x, so the same 4,5GHz OC might be possible
- regarding worse latency, i am pretty sure there are many workloads where those "just 2 extra cores" are more important than higher latency
- high clocks being inefficient, thats true, but i dont think enthusiasts care that much

finally, you expect 12C to have practical clocks 4,2GHz max, then you go on to say 7980xe will overclock better? If that 2 core difference between 7900x and 7920x means 300 MHz lesser overclock, than what about another 6 cores on top of that in case of 7980xe?

I kinda agree that 7900x and 7980xe might be the most interesting chips simply based on the fact they are both full fat dies, but i think if 7920x is soldered, thus potentially keeping the possibility of max clocks in the 7900x range, it could be even more interesting to some people, cause unlike 7900x, this one would on par with 16C Threadripper. Which 7900x cant be, no matter what. I mean, if you go on to pay extra for Intel product, it better be at least on par with AMD offering performance-wise, all around.
We don't know anything about solder in 12C so I assume it will be TIM again. If Intel can use it on Knights Landing, it can use it on 12C as well. It will have no effect on TDP, only on CPU temperatures.

7980XE overclocking better doesn't mean higher frequencies, but more performance for every extra Mhz due to more cores and better power efficiency at low clocks. So maybe you get 3.6Ghz all core speed. Power consumption isn't linear, above 4Ghz it skyrockets. If Ryzen clocked above 4Ghz, we would see this as well. Having "too many" cores will thus be actually an advantage of 7980XE. You won't need to depend on luck (silicon lottery) at all, as all of them will OC the same (eventually thermal issues). You tune turbo frequencies and get good single thread performance too.

You will pay hefty $2000, but may get performance of 28C Xeon in exchange.
 

aigomorla

Cases and Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
19,200
1,592
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Seriously i want to know whose bright idea it was at intel to use TIM under the IHS.

I bet you this is intels way of preventing all the RMA's done on CPU after killing them from Overclocking.
Its like you shall not pass unless u take the route to no RMA land.
The optional Performance warranty would also be voided if you delided that processor.

Sigh...

Im gonna wait and see what they did to the 7920k,.. and then compare it to TR.
The X299 board however is superior to X370 boards from what im looking at.
The M.2 Heatsinks which seem pretty common on the X299 boards are a definite must as those guys get really hot, and memory compatibility is near universal vs the X370.

However this may all change with the X399.

But so far, honestly IMO, unless CFL ends up being a glorified 7700k in gaming with 2 extra cores, i think AMD might have won this time, because im not seeing any improvements at all in SKL-X in gaming over the 7700K.
 

DrMrLordX

Lifer
Apr 27, 2000
17,666
6,663
136
x299 is still seeing weird NVMe/m.2 performance issues with Skylake-X though. I'd like to know what is causing that problem.
 
Aug 11, 2008
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Seriously i want to know whose bright idea it was at intel to use TIM under the IHS.

I bet you this is intels way of preventing all the RMA's done on CPU after killing them from Overclocking.
Its like you shall not pass unless u take the route to no RMA land.
The optional Performance warranty would also be voided if you delided that processor.

Sigh...

Im gonna wait and see what they did to the 7920k,.. and then compare it to TR.
The X299 board however is superior to X370 boards from what im looking at.
The M.2 Heatsinks which seem pretty common on the X299 boards are a definite must as those guys get really hot, and memory compatibility is near universal vs the X370.

However this may all change with the X399.

But so far, honestly IMO, unless CFL ends up being a glorified 7700k in gaming with 2 extra cores, i think AMD might have won this time, because im not seeing any improvements at all in SKL-X in gaming over the 7700K.
Yea, but Ryzen is no improvement in gaming either over 7700K. In fact in most cases still slower than either 7700k or Skylake X for gaming. I agree though, gaming performance of Skylake X is not as good as I had hoped for. It may improve with updates, but who knows.
 

VirtualLarry

No Lifer
Aug 25, 2001
51,678
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Yea, but Ryzen is no improvement in gaming either over 7700K.
Not true. It shows better minimum framerates, and thus, smoother gameplay. This has been benchmarked. True, it can't beat the "max" framerates of the 7700K very well, but, in the end, which is more important, once you reach the frame-rate of your display device?
 
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Zucker2k

Golden Member
Feb 15, 2006
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Not true. It shows better minimum framerates, and thus, smoother gameplay. This has been benchmarked. True, it can't beat the "max" framerates of the 7700K very well, but, in the end, which is more important, once you reach the frame-rate of your display device?
Does Ryzen have better minimum framerates than BDW-E or Skylake X? Just curious.
 

scannall

Golden Member
Jan 1, 2012
1,801
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Yea, but Ryzen is no improvement in gaming either over 7700K. In fact in most cases still slower than either 7700k or Skylake X for gaming. I agree though, gaming performance of Skylake X is not as good as I had hoped for. It may improve with updates, but who knows.
Since my gaming is done at 4k, there is no difference at all. When I see these 1080 benchmarks, I ignore them. They have no relevance for my uses.
 

dullard

Elite Member
May 21, 2001
22,975
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Intel Coffee Lake Core i5-8250U, 4 cores, maximum 3.4 GHz, in Acer Swift 3: http://laptopmedia.com/news/intel-core-i5-8250u-is-coming-acer-swift-3-to-get-it-early/

Perhaps 2.5-3.0 GHz sustained on all cores with cTDP up to 25 W.
Compare that to the equivalent Kaby Lake processor (7260U, 2 core, 2.2 GHz base, 3.4 GHz turbo). It shows basically what we should expect from Coffee Lake:
  • 2 more cores,
  • An increase in TDP (although ~25% less than the equivalent TDP if it were Kaby Lake),
  • A drop in base clocks to prevent the TDP from getting out of hand with the additional cores, and
  • Turbo clock will be about the same as Kaby Lake for the equivalent chip.
 

SPBHM

Diamond Member
Sep 12, 2012
4,998
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6c/6t sounds very interesting, specially if it can OC over 4.5ghz it will probably be the new favorite gaming CPU.
 
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dullard

Elite Member
May 21, 2001
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Core i7-8700K 6C/12T 3.7 GHz base, 12MB L3, 95W
Core i7-8700 6C/12T 3.2 GHz base, 12MB L3, 65W
Core i5-8600K 6C/6T 3.6 GHz base, 9MB L3, 95W
Core i5-8400 6C/6T 2.8 GHz base, 9MB L3, 65W
Core i3 gets 4C/4T

https://www.cpchardware.com/coffee-lake-approche

Finally someone posted. Should I leak the Turbo clocks? I didn't believe at first. :D:eek:
I'd like to see the turbos. So far those specs exactly match the expected changes in my post above (except I need the turbo to confirm).
 

TheGiant

Senior member
Jun 12, 2017
748
353
106
Not true. It shows better minimum framerates, and thus, smoother gameplay. This has been benchmarked. True, it can't beat the "max" framerates of the 7700K very well, but, in the end, which is more important, once you reach the frame-rate of your display device?
Can you provide numbers?

rarely seen it in any review that ryzen shows better min fps (and if you look at the run chart it is an outlier), in fact oced 7700k shows performance advantage in min fps that shows THE reason to upgrade from sandy

except this forum talk of BF1 MP

I see the 6/6 CFL as THE cpu of choice. enough threads for most of desktop uses, low power and TEH enough coarz gaming performance
 
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JoeRambo

Golden Member
Jun 13, 2013
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Since my gaming is done at 4k, there is no difference at all. When I see these 1080 benchmarks, I ignore them. They have no relevance for my uses.
This myth needs to die, sure not relevant for "Your uses", but creates a false sense of "enough performance for 4K@60hz".

There is in fact a huge difference. Of course impact depends on what games You are playing, but a faster CPU is faster. Frames per second is not "end all" stat for CPU's, even if we ignore the elephant in the room called "minimum frames".

Where a faster, "built for gaming" CPU matters is various games, think about turn times in strategy games like Civilization series / Endless series. Also simulation times in games like EU4 / Stellaris / HOI4. There is a world of a difference to play those on fast CPU. Just ask around Arma, Nintento emulation, flight sim crowds, fastest CPU there will be 7700K @ 5Ghz and no one will have "too much" of performance
And fool yourself no more, once you realize that faster CPU is helping in playing those games both directly and indirectly ( for example game/save load times ), you will come to realize that those 1080P tests are in fact a good proxy of well built CPU with good cache subsystem that facilitates inter thread communication, and those CPUs that don't do well there, tend to suffer in general gaming. All those guys with 4Ghz Ryzens are giving up 30-40% of that sweet ST performance vs current best in market.
 

scannall

Golden Member
Jan 1, 2012
1,801
1,293
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This myth needs to die, sure not relevant for "Your uses", but creates a false sense of "enough performance for 4K@60hz".

There is in fact a huge difference. Of course impact depends on what games You are playing, but a faster CPU is faster. Frames per second is not "end all" stat for CPU's, even if we ignore the elephant in the room called "minimum frames".

Where a faster, "built for gaming" CPU matters is various games, think about turn times in strategy games like Civilization series / Endless series. Also simulation times in games like EU4 / Stellaris / HOI4. There is a world of a difference to play those on fast CPU. Just ask around Arma, Nintento emulation, flight sim crowds, fastest CPU there will be 7700K @ 5Ghz and no one will have "too much" of performance
And fool yourself no more, once you realize that faster CPU is helping in playing those games both directly and indirectly ( for example game/save load times ), you will come to realize that those 1080P tests are in fact a good proxy of well built CPU with good cache subsystem that facilitates inter thread communication, and those CPUs that don't do well there, tend to suffer in general gaming. All those guys with 4Ghz Ryzens are giving up 30-40% of that sweet ST performance vs current best in market.
1080 gaming isn't the least bit relevant if you game at 4k. Further, if you actually use your computer for other tasks, a 'gaming' CPU will always perform worse. For example, I do a lot of 3d modeling and rendering. A 7700k is a poor choice for that job. Why someone would spend thousands on a computer, then use a 1080 TN panel is beyond comprehension. Makes not the least bit of sense.
 

Edrick

Golden Member
Feb 18, 2010
1,913
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x299 is still seeing weird NVMe/m.2 performance issues with Skylake-X though. I'd like to know what is causing that problem.
I have my NVMe (m.2) issues all sorted. It was a PITA for the first week however.

It was a combination of BIOS fixes and actual testing application updates. Now I am running full speed with 2 Samsung NVMe drives installed.
 
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Mar 10, 2006
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1080 gaming isn't the least bit relevant if you game at 4k. Further, if you actually use your computer for other tasks, a 'gaming' CPU will always perform worse. For example, I do a lot of 3d modeling and rendering. A 7700k is a poor choice for that job. Why someone would spend thousands on a computer, then use a 1080 TN panel is beyond comprehension. Makes not the least bit of sense.
A 1080P TN panel @ 144Hz or even 240Hz is a fine choice if you are a competitive gamer.
 

JoeRambo

Golden Member
Jun 13, 2013
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080 gaming isn't the least bit relevant if you game at 4k. Further, if you actually use your computer for other tasks, a 'gaming' CPU will always perform worse.
The problem with these forums is that there is much larger amount of people that are encoding video and rendering and doing distributed computing. But for general crowd 7700K would provide what is by far the best performance in games AND in "other tasks" like web browsing, office work.
Still my point stands, 1080P tests are a good proxy of CPU performance.
 

ManyThreads

Member
Mar 6, 2017
99
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Poor M.2 performance?
I have an 960 PRO 512GB In an ASUS TUF MK1, it will not go over 2/3 speed either in Samsung Magician benchmark or CrystalDisk. I hope it's just a BIOS thing, I really don't want to RMA my mobo and/or 960 Pro. And yes I am using Samsuing NVME drivers, not the Windows ones (but they had identical crippled performance)
 
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ManyThreads

Member
Mar 6, 2017
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Tested my 512GB 960 Pro using AS-SSD. Looks okay.


Also tested my four 2TB 850 EVOs in RAID-0 (8TB).


The X299 PCH seems to do a great job with SSDs.
Yours looks similar to mine - stuck around 2/3 speed. User benchmarks should show maximum performance or very close to it, lots of people have posted samples. Not sure whats going on with these boards, I can't figure it out.
 

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