Coffeelake thread, benchmarks, reviews, input, everything.

[rainy]

Guys how its possible to push 9900k 4,6Ghz all cores with TDP of 95W ?

I presume that TDP is only for the base clock and even here I would be a bit suspicious - 8700K with six cores at 3.7 GHz have the same 95W.
https://ark.intel.com/products/126684/Intel-Core-i7-8700K-Processor-12M-Cache-up-to-4_70-GHz

 

[The Stilt]

I presume that TDP is only for the base clock and even here I would be a bit suspicious - 8700K with six cores at 3.7 GHz have the same 95W.
https://ark.intel.com/products/126684/Intel-Core-i7-8700K-Processor-12M-Cache-up-to-4_70-GHz

The issue is that on Intel the TDP is an actual power limit (PL1).
So either the claimed clocks or the TDP are inaccurate, or the process variant is significantly more efficient than its predecessor.
Most likely either of the claimed specs is inaccurate IMO.

 

[PeterScott]

Good points, but I don't think cinebench represents the best case scenario for HT/SMT scaling.

For example, in Blender a 8700K is 47% faster than a 8600K. Even a 7700K beats the 8600K and that is with a 50% core deficit. Clock for clock the 8600K edges a 7700K but only barely. A 8700K only has 33% less cores than a 9700K.

https://www.gamersnexus.net/hwreviews/3157-intel-i5-8600k-review-overclocking-vs-8700k-8400/page-3

In Blender at least, based on this a 8700K would beat a 9700K if it is indeed an 8/8 chip. Other apps and benchmarks will be a mixed bag probably, like your CB example

You may have found the best case for HT in blender, but over a variety of software it's probably averages more like 10%.

I would definitely chose 8/8 over 6/12 if they were capable of the same clock speeds. Because I don't run Blender or the software Cinebench is based on.

The only significant fully parallel software I run is video encoding (Handbrake). So for me it is really only there that 6/12 would have a chance of beating 8/8. Have you seen that one clock for clock?

Like I said earlier, this one is close, and I can see Intel either not offering one of 8/8 or 6/12 in the 9 series desktops to avoid that overlap.

 

[psolord]

I cursed at Intel for not having an 8/8 model the other day. Glad I was wrong.

 

[JoeRambo]

I cursed at Intel for not having an 8/8 model the other day. Glad I was wrong.

Yeah, those 2500K's of generation as usually great buys. While i love my L3 cache and going to get 8C16T, 8 CFL cores and 12MB of L3 is plenty even without HT and comes with nice price discount.

About 25% boost in both cases.

That was for Neh/Westmere generation. Since then Intel has improved both core execution resources ( in Sandy Bridge, Haswell and esp in Skylake) and cache hierachy to feed them. Plus of course contemporary hexacore has faster mem.

 

[happy medium]

Looks like a 8 core ,8 thread 9700k @ 5ghz is a definite possibility.
Match that with an overclocked gtx1180 and it could drive gamers 1440p monitors at 144hz for a few years.

With the ps5 and Xbox 2 more than likely having 8 Zen cores in 2020/2021, with a gpu around the performance of a Vega 64, it should be a good sweet spot for gamers.

 

[frozentundra123456]

Valid point ... Call me naive, but I think they have had so long to work on this (4-5 years+ with all the delays) that they could well have gone back to the drawing board and bumped up the uarchitecture, maybe increased the caches or something. Especially once they realised probably by 2016 that 10nm was a shot process and even 10nm+ would not achieve the same clocks as 14nm++ (nevermind 14+++).
I don't know whether the spectre fixes and Ryzen's unexpected competitiveness could have influenced this or whether these events were too late in the game?.
Either way by the time Kabylake was launched as a stopgap they must have had a tough decision to make, that's where 14nm++ & 14nm+++ 6 & 8 core skylake dice came in to hold the fort whilst they Sellotaped 10nm+ together with a rejig of icelake microarchitecture...

Perhaps they had the foresight (alongside some handy information from poached ex AMD employee's) to scrub the IGPU and put on some more cores to the MESH..like 12 for instance.

Just speculation on my part, but I can't fathom how intel is going to compete with zen 2 with an 8/16 icelake, that has only 5-10% IPC and lower clocks than coffeelake can you?

Right now coffee lake has about 20% clockspeed advantage and some ipc advantage. So if the eight core can hold close to that clockspeed, CL would have about a 25% advantage over Ryzen. So Zen 2 will have to have a combination of 25% clock speed plus ipc gain to even equal CL. They may achieve that, but maybe not, and gaining more than that even with a new architecture and process seems like a tall order to me. So I dont think Zen 2 will necessarily be the CL killer some are assuming it to be. Not saying it wont be, but I dont think it is a forgone conclusion like many are assuming it will be

 

[amdfan111]

The issue is that on Intel the TDP is an actual power limit (PL1).
So either the claimed clocks or the TDP are inaccurate, or the process variant is significantly more efficient than its predecessor.
Most likely either of the claimed specs is inaccurate IMO.

The "leak" could very well be fake, but the TDP is defined for the base frequency, which is also suspect. The turbo frequency is not constrained by TDP at all, but only by the VR specification (ICCmax) and circuit timing. So we'll see "95 W" chips that run at 300-500 W out of box, similar to Skylake-X.

 

[french toast]

Right now coffee lake has about 20% clockspeed advantage and some ipc advantage. So if the eight core can hold close to that clockspeed, CL would have about a 25% advantage over Ryzen. So Zen 2 will have to have a combination of 25% clock speed plus ipc gain to even equal CL. They may achieve that, but maybe not, and gaining more than that even with a new architecture and process seems like a tall order to me. So I dont think Zen 2 will necessarily be the CL killer some are assuming it to be. Not saying it wont be, but I dont think it is a forgone conclusion like many are assuming it will be

Your right, it is not a foregone conclusion that Ryzen 3 can best the worst case version of icelake I specified, let alone the one I think they will launch.
But I am certain we will get skylake matching ipc with zen 2 (15% needed), with better SMT and more cores to boot.
I also think a binned 3800x could match coffeelake S 5ghz ST also.
That would make zen 2 match coffeelake s across the board but crucially offer better ST performance in popular benchmarks like cinebench..(skylake only ~6% ahead IPC)..and would destroy 8/16 skylake in multithreaded apps. (Assuming 12 core or above).

That would mean icelake would pull ahead again in ST perf (probably same difference between pinnacle ridge Vs coffeelake S now)..whilst being a good battle in MT..depending on core counts.

2019 is sure going to be exciting.

 

[The Stilt]

The "leak" could very well be fake, but the TDP is defined for the base frequency, which is also suspect. The turbo frequency is not constrained by TDP at all, but only by the VR specification (ICCmax) and circuit timing. So we'll see "95 W" chips that run at 300-500 W out of box, similar to Skylake-X.

TDP is always PL1 (sustained power limit) on Intel.

Base frequency doesn't exist unless Turbo is disabled.

https://newsroom.intel.com/wp-conte...04/8th-gen-intel-core-h-series-press-deck.pdf

Page 34.

 

[mikk]

TDP is always PL1 (sustained power limit) on Intel.

Base frequency doesn't exist unless Turbo is disabled.

https://newsroom.intel.com/wp-conte...04/8th-gen-intel-core-h-series-press-deck.pdf

Page 34.

There is a PL2 limit for sure, same for the new Xeon. The reported leak is most likely a fake though.

https://www.anandtech.com/show/12199/intel-launches-coffee-lake-xeon-e-entry

 

[amdfan111]

TDP is always PL1 (sustained power limit) on Intel.

Base frequency doesn't exist unless Turbo is disabled.

https://newsroom.intel.com/wp-conte...04/8th-gen-intel-core-h-series-press-deck.pdf

Page 34.

Of course the base frequency exists. TDP is the worst-case non-AVX power at the base frequency, which directly implies that the base frequency is the minimum frequency the processor runs at when limited to TDP by PL1. If you run a power virus, I'm sure you'll see the frequency approach base, especially on those parts where Intel makes an actual effort* into validating the base frequency (mobile and server).

* For desktop, Intel clearly doesn't give a fuck about base frequency, as can be seen from Skylake-X and Coffee Lake. They pick some lowball figure to make the TDP "work" and ship them to customers drawing 200+ W.

 

[Zucker2k]

Of course the base frequency exists. TDP is the worst-case non-AVX power at the base frequency, which directly implies that the base frequency is the minimum frequency the processor runs at when limited to TDP by PL1. If you run a power virus, I'm sure you'll see the frequency approach base, especially on those parts where Intel makes an actual effort* into validating the base frequency (mobile and server).

* For desktop, Intel clearly doesn't give a fuck about base frequency, as can be seen from Skylake-X and Coffee Lake. They pick some lowball figure to make the TDP "work" and ship them to customers drawing 200+ W.

This is false. Show us a coffee lake chip drawing 200+ watts at stock, please.

 

[epsilon84]

This is false. Show us a coffee lake chip drawing 200+ watts at stock, please.

I too would like to see an example of this, especially on a CFL chip. Well, I already know its not true, because I own a 8700K and there is no way it would overclock to 5GHz on air (or even stock speeds) without thermal throttling if it was a 200W chip at stock. Pretty sure my HSF (CM Hyper 212) struggles with anything over 150W.

From what I've seen, under a heavy MT workload like Blender, a stock 8700K does draw around 95W. So for a 8/16 9900K to have the same TDP and run at higher turbo clocks? I'm pretty dubious about that, unless Intel managed to drastically improve the 14nm process again.

 

[The Stilt]

Of course the base frequency exists. TDP is the worst-case non-AVX power at the base frequency, which directly implies that the base frequency is the minimum frequency the processor runs at when limited to TDP by PL1. If you run a power virus, I'm sure you'll see the frequency approach base, especially on those parts where Intel makes an actual effort* into validating the base frequency (mobile and server).

* For desktop, Intel clearly doesn't give a fuck about base frequency, as can be seen from Skylake-X and Coffee Lake. They pick some lowball figure to make the TDP "work" and ship them to customers drawing 200+ W.

Typically the lowest an 8700K will go at stock is 3.95GHz during Prime95 FMA3.
If the power limits are configured as they should (95W PL1, 119W PL2), it is impossible for the CPU to consume more than that in any workload.

Improper configuration of the power limits is not something which Intel does, but something that the motherboard ODMs do (and which poor reviewers do not counter).

 

[The Stilt]

Also here is Hardware.fr's measurements on 8700K during Prime95 28.10.

The VRM efficiency is typically < 83% on modern boards.
113.8 * 0.83 = < 94.454W.

 

[elpokor]

Typically the lowest an 8700K will go at stock is 3.95GHz during Prime95 FMA3.
If the power limits are configured as they should (95W PL1, 119W PL2), it is impossible for the CPU to consume more than that in any workload.

hmm, that PL2 is oddly close to the power consumption that a "good sample" of 8700K draws during a similar torture test with MCE settings (47x cores, 44x cache)

MCE draws almost exactly 120.6W/1.210V=100Amps average during torture testing, I've seen this aswell on a "bad sample" of 8700K and it drawed high 120s to low 130W while needing 1.280Vcore minimum to be stable. Mind you both CPUs had the toothpaste replaced with liquid metal, so it should be comparable to a soldered one.

Now, on the overclocking speculation... bumping +300Mhz across all cores and cache (50x cores, 47x cache) on the bad sample turned out to be impossible even with 1.45V. It maxed out at 49x/46 with terrible temps and 1,4V. The good one can do the +300Mhz bump, but it takes almost 158/1.341=118Amps to get there:

if any of you guys have a golden sample or an 8086K around there, feel free to repeat this test and post your results. I manually reset the sensors when the voltage spikes as the test begins and then come back around the 4 minute mark to take the screenshot when it finishes. It may be worth a separate thread if you feel it would clutter this one.

The bottom line is that going from PL2 (which seems to be equivalent to MCE activated) to +300Mhz takes 158/120=131.6%Watts. I can't see 5.5Ghz happening... heck, even 5.1Ghz truly stable in octacores would be somewhat miraculous given that they haven't anounced new improvements beyond 14nm++ and one would assume they've allocated those engineering resources to fix the 10nm mess.

 

[jpiniero]

The frequencies I imagine would be for non-AVX only.

 

[coercitiv]

PL2 is oddly close to the power consumption that a "good sample" of 8700K draws during a similar torture test with MCE settings (47x cores, 44x cache)

PL2 (which seems to be equivalent to MCE activated)

PL2 = configurable Power Limit which mobo makers / system integrator can set according to their needs
MCE = profile, set of parameters (CPU Multi / various voltages / power limits etc) a mobo maker may include in their BIOS

There is no equivalence between the two, since more often than not overclockable boards ship with power limits disabled or set so high only high overclocks would reach. Let me repeat that, expect most Intel based Z boards to come with PL1 and PL2 disabled or set so high as to not matter for the average overclocker. Only look for power limits in more budget oriented boards, or mITX Z boards.

 

[JoeRambo]

MCE draws almost exactly 120.6W/1.210V=100Amps average during torture testing, I've seen this aswell on a "bad sample" of 8700K and it drawed high 120s to low 130W while needing 1.280Vcore minimum to be stable. Mind you both CPUs had the toothpaste replaced with liquid metal, so it should be comparable to a soldered one.

The only nitpick i have here is that Your "settings" are not stock for memory, VCCSA and VCCIO. Memory that fast and 20-30% higher voltages are bound to generate extra load compared to stock 2666 dram.

The problem with this thread lately is the same we had before 8700K came out. There were plenty of people claiming it will be impossible to hit 5Ghz on 8700K, that 7700K is in fact rebadged 6700K and does not overclock better etc. The usual suspects were all here.

Fast forward to this day - plenty of chips hitting 5Ghz and there was clear improvement going from 6700K->7700K->8700K even if people deny it. If silicon is willing, and Intel improves cooling by returning to solder, i am certain 8C will hit 5Ghz no problem. The 212 crowd will suffer of course, but everyone else will be just fine, like always.

 

[Bouowmx]

Saw on Reddit r/hardware: Core i7-9700K (8 cores, 8 threads, 3.6 GHz, 12 MB LLC) in SiSoftware and supporting evidence for Coolaler.

 

[coercitiv]

The only nitpick i have here is that Your "settings" are not stock for memory, VCCSA and VCCIO. Memory that fast and 20-30% higher voltages are bound to generate extra load compared to stock 2666 dram.

Settings were not stock to start with, since MCE increases 6c multi from 43x to 47x.

 

[JoeRambo]

Settings were not stock to start with, since MCE increases 6c multi from 43x to 47x.

Ofc, but DDR4 4000 CL17 is not your average MCE enchanced "stock" either. Wattage would drop quite some if memory was 2666 with typical latencies by lowering linpack numbers and load.

 

[amdfan111]

Typically the lowest an 8700K will go at stock is 3.95GHz during Prime95 FMA3.
If the power limits are configured as they should (95W PL1, 119W PL2), it is impossible for the CPU to consume more than that in any workload.

Improper configuration of the power limits is not something which Intel does, but something that the motherboard ODMs do (and which poor reviewers do not counter).

As I noted, Intel makes no effort to provide tight bounds on the power consumption of "desktop" (overclocked laptop) parts. If you try this on mobile or server, you will see it approach the base frequency, with maybe 2-3 bins of margin on most parts. Actually, if you look at the reviews for the controversial "i9" MacBook, it runs at 3.1 GHz (base 2.9) when editing videos at 45 W.

Also here is Hardware.fr's measurements on 8700K during Prime95 28.10.

The VRM efficiency is typically < 83% on modern boards.
113.8 * 0.83 = < 94.454W.

The International Rectifier series of VRMs that everyone and their mother uses has 94% efficiency at optimum current, and 92+% across a broad spectrum. Some newer Infineon chips that are starting to trickle down to consumer have 96% efficiency. Inefficient VRMs are a myth.

 

[The Stilt]

The International Rectifier series of VRMs that everyone and their mother uses has 94% efficiency at optimum current, and 92+% across a broad spectrum. Some newer Infineon chips that are starting to trickle down to consumer have 96% efficiency. Inefficient VRMs are a myth.

The power stage itself might come close to the advertized figures in perfectly optimal situations (low current, >= 10% duty, low fSW), but the power stages (or mosfets) are not the only component in the VRM which has losses.
There are significant losses in the inductors and the capacitors, and some in the PCB as well.

> 85% efficiency is generally not happening even on Intel HEDT platforms, where currents are lower and VRM duty cycle is higher due to the presence of the FIVR (high output voltage).