- Mar 3, 2017
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Yea, this is depressing.Actually it is worse.
AMD basically stopped shipping iterations of Bulldozer for DIY desktop. But they really did polish that turd almost every year through 2015! Zen 5 won't be getting that yearly treatment.
I really doubt that. I mean I’m not an expert, but it it’s been shown in other reviews it takes on the order of ~ 1 ms to hit boost frequency
~ 100 ns is on the order of RAM access latency, I can’t imagine it coming out of any kind of sleep anywhere near that fast. The voltage regulation, everything else will respond on timescales much longer than that. Just based on my intuition and respect for orders of magnitude I don’t think there can be a software (Windows driver) reason to explain the extra 120 ns. Microcode, maybe.
This really shouldn't be necessary. They really need to change this.Whelp, we have confirmation the review guide was a mess. They had to message reviewers later and tell them the dual CCD parts need special attention. You can click on the image to open timestamped GN 9950X review.
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Anyone know of a good program to measure core to core latency ?
I tried MicroBenchX.C2CLatency and and it spat out this
View attachment 105318
When i tried to save the data window closed, and i'm not running that again (~20min runtime)
If im reading it right, its ~20ns inter CCD and up in the 150-180ns range for cross ccd (?)
Only if this redesigned core somehow can run @5.4-5.5Ghz with 3D cache.So are we still expecting X3D in September? Mid or end of? Based on what?
Any chance it will magically be able to save Zen5?
Is there a detailed description anywhere of what we are seeing in this graph and how it was produced?
I hope the regression versus Zen 4 < 125 W is an artifact of the particular desktop setup. (Because Turin vs. Genoa eventually needs to have a very different outcome than this one...)
[It's not a rehash of the older 9950X *ES* measurements, is it?]
Ummm...hate to break it to you but Zen 5 will 100% be getting that "turd polishing" treatment. It is AMDs "new foundation" for x86 CPUs. Zen 6 will take Zen 5 core arch, put on a smaller process, a few various enhancements (possibly with a 16 core CCX per CCD), along with presumably brand new uncore / IOD setup. Then Zen 7 will iterate on what Zen 6 has done. All will use the Zen 5 core.Actually it is worse.
AMD basically stopped shipping iterations of Bulldozer for DIY desktop. But they really did polish that turd almost every year through 2015! Zen 5 won't be getting that yearly treatment.
Apparently a poor bandaid just like it has to happen when ISV, OS maker, OEM and CPU maker are not quite getting together for a more targeted implementation. Like assigning CPU affinities to the game process at its startup, maybe.The Core Parking seems to me more like a band aid to the problem
Well, we learned quite a bit more (how it behaves on GNR, whether or not SMT disabled in the BIOS influences its behavior, what the impact in actual workloads is, plus the commentary that moving the various resources between 1T mode to 2T mode is not entirely trivial and has got latencies). There are still more pieces to the puzzle left to discover (or not). Such as why this is counter to what M. Clark said when being interviewed.after decoder mystery got solved
Emphasis on yearly treatment.Ummm...hate to break it to you but Zen 5 will 100% be getting that "turd polishing" treatment. It is AMDs "new foundation" for x86 CPUs. Zen 6 will take Zen 5 core arch, put on a smaller process, possibly with a 16 core CCX per CCD, along with presumably brand new uncore / IOD setup. Then Zen 7 will iterate on what Zen 6 has done. All will use the Zen 5 core.
Any info which allows for an estimation of core/uncore power split?Cinebench R23 PPT scaling.
Regression in very low wattages are also present in Geekerwan’s Strix Point review if I recall correctly.
Any info which allows for an estimation of core/uncore power split?
thanks, that worked out well 👍Try this. https://github.com/nviennot/core-to-core-latency/releases/tag/v1.0.0
Edit: May need to run as admin.
thanks, that worked out well 👍
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Only if this redesigned core somehow can run @5.4-5.5Ghz with 3D cache.
I guess you are not using this fancy driver so we can exclude this as a cause, therefore it's a band aid and they botched something it seems...thanks, that worked out well 👍
I guess you are not using this fancy driver so we can exclude this as a cause, therefore it's a band aid and they botched something it seems...
That fancy driver as you put it is not a fix, its a work-around trying to mitigate the problemI guess you are not using this fancy driver so we can exclude this as a cause, therefore it's a band aid and they botched something it seems...
7950x3d for comparison.thanks, that worked out well 👍
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Did you use this cmd to run ? Or just make the window larger so its easier to read👍7950x3d for comparison.
That fancy driver as you put it is not a fix, its a work-around trying to mitigate the problem
Yes, I just copied what you did. Didn't output it to a csv file though. Heres one where I did.Did you use this cmd to run ?
core-to-core-latency 5000 --csv > output.csv
Yes I agree. I simply meant that some people thought driver is the reason for high latency and since you are not using it, we know it's not.That fancy driver as you put it is not a fix, its a work-around trying to mitigate the problem
That's at least my take if i understand it correctly
That would make sense if this was burst behaviour but I guess you can keep all cores active [disable power saving options in the bios should prevent lower power states? maybe something in the windows power planes] and the picture wouldn't be changed fundamentally. Might be that test itself is enough to keep the cores awake.Yeah, that's kind of how I see it. I think this behavior was intentional to lower the power consumption of the overall package when only needing a few cores. The driver is there to try and stop the OS from using both CCDs when only 1 is needed, to avoid having to wake up the other cores and suffer a power and performance penalty. Though, it seems to be mostly concerned with gaming loads, or whatever it sees as a gaming load.