Intel Skylake / Kaby Lake / Coffee Lake Thread - Skylake-X reviews out (page 501)

Discussion in 'CPUs and Overclocking' started by Sweepr, Apr 16, 2015.

  1. shortylickens

    shortylickens No Lifer

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    OK, so my 7700k is doing what I want, which of course is improving framerates in some games that previously lagged a bit.
    Fallout 4 is much smoother in the downtown area, as is Subnautica anywhere on the map, and a few others that were too much for the i3. Desktop stuff like large photo work has not improved noticeably, but then I never benchmarked those kinds of things.
    Its running very hot even with a Cooler Master Hyper TX3. And the fans are always loud. I may need to look at water cooled solutions.
     
  2. Markfw

    Markfw CPU Moderator VC&G Moderator Elite Member
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    Why are you posting in this thread ? Its about Skylake / Kaby Lake. I am confused
     
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  3. imported_ats

    imported_ats Senior member

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    Pretty far, realistically you are looking at a production cost in the range of ~$100 just based on napkin math. Honestly, the production cost is likely significantly less than that now with the fabs pretty much fully amortized.



    Markfw provided absolutely ZERO evidence that is relevant to our discussion. And no, 4x naples in a MCM doesn't have an upper bound of 4x power. Significant portions of die and I/O aren't even used in Naples. For I/O, Naples really isn't using even 1/4th of the I/O required for a 4x MCM.
     
  4. imported_ats

    imported_ats Senior member

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    Unfortunately we don't know what that rumored 205W figure represents. For example, Intel already sells custom spec ~200W E5v4's to some vendors to use in water cooled systems (allowing them to in effect run full time at max turbo). Nor do we know what all is included in that processor (rumors of both HMC and integrated dual 100g OPA abound with dual 100g chips taking 20-30W of power alone).
     
  5. imported_ats

    imported_ats Senior member

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    You'll get some form of inter thread communication of quite literally every memory access. And yes inter-thread communication has been an issue going back to essentially the beginning of multi-context processors. There are two types of inter-thread communication: implicit and explicit. Explicit inter-thread communication is caused by the program actively exchanging data between threads while implicit inter-thread communication is the burden put on all memory activity in order to maintain a coherent view of memory (aka cache coherency and MOM - Memory Order Model).

    On chip interconnection networks are rarely a bottleneck because you can throw a LOT of wires at the problem, but unfortunately once you have to go off chip, you are at the mercy of bumps and pads and the amount of wires and the performance of those wires quickly becomes an issue. It quickly becomes impossible to put enough interconnect in for worse cases and in addition you have extra latency getting on and off chip as well. So instead you end up designing around average case and practical worst case.
     
  6. tamz_msc

    tamz_msc Golden Member

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    The 205W TDP is more or less confirmed from the leaked OEM board featuring the C621 chipset.
     
  7. LTC8K6

    LTC8K6 Lifer

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    Last time I checked, the 7700K was a Kaby Lake chip.
     
  8. itsmydamnation

    itsmydamnation Golden Member

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    this will be my last OT post in this thread,

    https://tu-dresden.de/zih/forschung...benchit/2014_MSPC_authors_version.pdf?lang=en

    Code:
    location latency in ns
                           L2    L3     RAM
    local                   9.1
    2nd core                19.5 27.3 82.3
    on-chip                88.6
    2nd die in MCM         129 116 133
    other socket, 1 hop     136 123 146
    other socket, 2 hops     178 164 187
    including probe (max)    198 185 -
    Even on bulldozer the difference between an on chip not local L2 and a MCM L2 access is only 33%. But then go an look at the different SOC uarch's to see just how much better Zepplins is then Bulldozers.

    Bulldozer used the same HT interfaces on MCM and inter socket. Bulldozer had the SRQ which was one giant bottleneck even accessing the directory cache. To get to the other chip in the package you had to go SRQ-> crossbar->HT->crossbar->SRQ->directory/L3/L2.

    Zen is much better, cache directories are attached directly to the UMC's, the UMC's/GMI's/io Hub/Core Complexs are attached to the fabric, The L3 holds tags for the L2 within a CCX, so a much more scalable solution.

    Then even just look at the size and number of phy's for the GMI interfaces, sure they are going to cost you some power to go over the interposer but nothing like PCIe or memory accesses. Fudzilla's leaks( everything else in them is correct) had each of those GMI interfaces at 25GB/s which is twice the bandwidth of BD's HT (12.8), so we are looking at around 200 GB/s of GMI bandwidth for each SOC, what we dont know is if it is full mesh or ring (i think ring is more likely with 4 controls and 8 phys with only 4 stops) .

    So then it comes down to latency and we dont know what it is but i'll bet you its no more then the 40ns of BD, i recon it will be around the 20ns mark per hop just like inter CCX on the same chip. Just look at BD the difference for inter proc vs inter mcm is only 13ns so distance isn't a big contributor and we know Zeppelin has been designed from ground up to have a distributed memory hierarchy

    Last but not least i'll leave you with these tidbit from an OEM when we where talking about 32 core naples:

    https://forum.beyond3d.com/threads/amd-ryzen-cpu-architecture-for-2017.56187/
    We know why DP doesn't look as good, GMIx needs to use PCIe lanes, so in 2P you loose 1/2 your lanes and have nowhere near the bandwidth of the on package fabric.
     
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  9. imported_ats

    imported_ats Senior member

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    What numbers are you comparing there to get 33%? From my reading there it is 45% (129 vs 88.6). And it is only that low because the uncore is so incredibly bad. Intel's L2 latencies are like 1/2 or less depending on chip.


    If those GMI are running at high frequency, they'll still take a decent amount of power.

    Um, care to link to a post rather than an entire thread?
     
  10. tamz_msc

    tamz_msc Golden Member

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    Uh semantics? 88ns is 33% faster than 129ns or 129ns is 45% slower than 88ns.
     
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  11. crashtech

    crashtech Diamond Member

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    Any idea WHEN we will know whether at least some Z270s will support 6c Coffee Lake?
     
  12. Bouowmx

    Bouowmx Senior member

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    When motherboard manufacturers post "next-generation ready" articles some weeks prior to launch.
     
  13. Bouowmx

    Bouowmx Senior member

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    Edit: Made a mistake in this post
     
  14. LTC8K6

    LTC8K6 Lifer

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    BIOS updates...
     
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  15. Sweepr

    Sweepr Diamond Member

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    The 'Ice Lake' entry mysteriously disappeared from their search, though I can (still) open the comparison link provided here.
     
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  16. IntelUser2000

    IntelUser2000 Elite Member

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    Skylake server has one 100G OPA. Xeon Phi has 2 and adds 15W. Also HMC has never been on the official roadmaps and confidential slides. FPGAs and iGPUs are though.

    On the topic of TDP, there's too much speculation based on leaks. It can actually be wrong you know. GPU-Z for example is nearly almost wrong on the TMU/ROP stats for Intel iGPUs. The information in that case is limited to what the program author knows about the product. So the arguments are completely pointless. Take breather and stop acting like kids?

    IMO 205W is realistic for 28 cores and 2.5GHz. 250W may be for a rumored even higher 32 core part with everything enabled.
     
  17. mikk

    mikk Platinum Member

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    It disappeared from the official ranking, the entry still exists under the old link. Most likely removed from Geekbench because of the oddly fast memory scores, it says: "This result has been flagged as inaccurate"
     
  18. jpiniero

    jpiniero Diamond Member

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    The people at ServeTheHome made a good point... final Skylake-SP has been available to the cloud providers for some time. It's just you that have to wait until May 22nd.
     
  19. frozentundra123456

    frozentundra123456 Diamond Member

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    Yea, it's more on topic than all the posts about Ryzen.
     
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  20. ehume

    ehume Golden Member

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  21. Ajay

    Ajay Diamond Member

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    Multi Chip Module
     
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  22. coercitiv

    coercitiv Golden Member

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    The /s was strong in that post...
     
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  23. thepaleobiker

    thepaleobiker Member

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    Not sure if this helps with Skylake-X, but Skylake-EP CPU popped up on Ebay with some interesting specs :-

    "
    Some of Intel's new Skylake-EP processors have appeared on eBay, with the seller claiming that this model is a 28-core 2GHz unit called the E5-2600 V5.

    The images of this new CPU match what we have already seen in LGA 3647 CPU leaks, though at this time is is difficult to tell if this listing is genuine. Regardless, whoever one of these two matching CPUs will need an LGA 3467 motherboard to use it, motherboards that are not publically available at this time.

    While there is nothing illegal about this listing, it is certainly one that Intel will need to investigate, as at this time Skylake-EP is only available to select early partners, which should leave the company wondering who is selling these samples to the public.

    This Intel Xeon CPU is listed with the P 8136 name, which does not match any known Intel naming scheme, though this CPU is listed as a 28-core, 56-thread Xeon with 38.75MB of cache and a TDP of 165W.
    "

    Regards,
    Vish
     
  24. shortylickens

    shortylickens No Lifer

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    Its official, liquid cooling is my fave.

    Before: the 7700k was idling at 70 and maxing at 100.
    After: the 7700k idles at 35 and maxes at 69.

    If anyone wants to try it:

    https://www.amazon.com/gp/product/B015E14J9M/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

    I picked up a damaged box version for 63 dollars. It was easy to install except for mounting a little bracket on the underside of my motherboard. And of course, its quiet.
    Now its time for OVERCLOCKING!
     
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  25. richierich1212

    richierich1212 Platinum Member

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    What is your overclock/voltage @?
     
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