The Stilt
Golden Member
- Dec 5, 2015
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95 Watts at 1.4V is not even close to 95 Watts at 1.1V (don't know the voltage range for Zen)
We have to return on this subject too, once the reviews are out
95 Watts at 1.4V is not even close to 95 Watts at 1.1V (don't know the voltage range for Zen)
I went back to CPC's claim of 35% higher performance of Zen 1C/2T Vs PD 1C/2T. It turns out that according to this we have A0 sample they had tested achieves around 1.69x IPC without SMT Vs PD core(without its CMT). Hardware.fr found out in their initial FX8150 review that average gain from CMT is around 1.53x, while SMT on intel SNB core netted 23.4% on average. I assumed that Zen will be no worse than SNB when it comes to SMT gains. Pilderive core is baseline 1.
One core PD performance without CMT: 1/1.53=0.65
One core Zen performance without SMT: 1.35/1.23~=1.1 => Zen has 1.1/0.65~=1.69x or 69% higher IPC.
From AT Carrizo review we have generational performance uplifts calculated for PD, Kaveri and Richland. In summary from PD core to Carrizo core we have around 15.5% more IPC (average figure from apps and games). Now we can see how much better than Carrizo is the A0 sample that CPC tested: 1.692/1.155~=1.46 or some 4.6% better than what AMD claimed. If there are any performance hindering bugs on that sample I don't expect them to affect the IPC by more than 5% (from A0 to whatever retail stepping we end up with). In conclusion, I think at best the IPC will be 53% better, at worst we are having around 45% better IPC - the average figure of course. Maximums and minimums will likely exist and will vary a lot from benchmark to benchmark. Overall the core seems to be very strong and close to Haswell/Broadwell level. I expect 4-5% overall lower than Broadwell-E and around 6-7% lower than Skylake level, basically AMD's Haswell version.
Well, I'm walking into somewhat of a minefield here, but the AMD/GCN cards do have a small design "fault". It's not relevant for gaming, but they are quite power hungry during video decoding, because AMD chooses to run the memory at full speed. Again this is not an issue as such if you use your PC for gaming, but there are a few situations where it is relevant.
Maybe I phrased it wrong, A0 was referring to Zen part used by CPC in their review.On PD the average CMT yield is >= 75%.
What A0 stepping Carrizo are you talking about? AT used Athlon X4 845 retail part for the review, which features the only available final silicon version (CZ-A1).
Hardware.fr found out in their initial FX8150 review that average gain from CMT is around 1.53x,
Well if I take the 70% average CMT gain we would end up at 1.88x IPC gain over PD and 63% gain over XV core which I believe is not realistic. Unless of course Zen has 35% gain from SMT(not impossible) in which case we are back at similar numbers as in my original post: ~72% over PD, 49% over XV. So either SMT gain on Zen is a lot greater or CMT gain on PD core is not ~70% on average. Former is likely to be correct as there are speculations that Zen sees more SMT gains due to FP co-processor model AMD used.
Yes, for BD they do. Also I assume that those workloads are similar to what we have seen in Zen preview. The workloads are not the same of course (hardware.fr Vs CPC's preview) but the performance picture will not vary that much.Do the figures you mention refer the workloads in the chart you posted?
Yes, for BD they do. Also I assume that those workloads are similar to what we have seen in Zen preview. The workloads are not the same of course (hardware.fr Vs CPC's preview) but the performance picture will not vary that much.
If AMD beats thats IPC, without SMT, like they said, then all that can be said is kudos, that they've made a revolutionary and impressive design. K8 v2.I hope this won't cause another class action suit. And what should we tell the "up to 40%" believers?.
Good to know, but again, this is something AMD should control and remedy before launch. Not for an end user or reviewer to play around with.The bug (often compared to the TLB bug) might cause SB level IPC then. Any leaks out there might also suffer from this.
Quality components and I'd have no issues with even 4+2 designs. Even boards like the Asrock 890GX (4+1), we ran 1.5v 9850BEs 24/7 std aircooling for nearly a year no problem. That was 90+20A stock, so you were looking at >200W after OC there.It looks like it has 7 chokes / phases at first, but there is an eighth choke in there.
It's kind of weird. This looks like a mid range board at best, nothing too special
In particular, what are their Idd limits for each core/component. Low Idd and such VRMs would be fine but I doubt Idd will be low.Do we have any information on what voltages or power planes Zen products need to work? This being a socket that can support APUs or CPUs, both being SoCs with a southbridge/FCH in there too..
So the GPU side must be pretty darn powerful to require at least 3 MOS. Good to know!That appears to be a pretty standard mainstream board, not the high-end (UP-series) we've seen before.
4+3 was chosen as one-size-fits-all type of solution, which isn't really good for anything else but the 65W Bristol and Raven Ridge APUs.
We definitely do not want 8+2 phase boards, unless we have no intention of using the same board with Raven
Despite the concerted effort in these forum to discredit it, power consumption does matter, and Polaris was a dud in this area. It was especially disappointing after all the hype by AMD (and the fans in this forum) about 2.5x performance per watt improvement, how it would beat nVidia in efficiency, blah, blah, blah, when the majority of cards failed to even come close to that. In fact, despite AMD's backtracking that it was for only one model, I dont know if any model ever reached that efficiency. It was also quite entertaining to see all the posts about how wonderful polaris would be in performance per watt, and the desperate backtracking and reversals of field when it turn out nVidia was still more efficient and we were then told to change our light bulbs and quit drinking beer instead of buying an efficient card.what's the problem with Polaris? It is already better than its more expensive competitor, the 1060 6GB. Yes, there was TONS of hype before Polaris, but look at where it is now, and what people were saying about "where it would be" only 6 months ago.
I'm actually impressed.
So the GPU side must be pretty darn powerful to require at least 3 MOS. Good to know!
But the question still remains unanswered: if that really is IPC over EXC they mentioned, or, throughput
It was especially disappointing after all the hype by AMD (and the fans in this forum) about 2.5x performance per watt improvement, how it would beat nVidia in efficiency, blah, blah, blah,
We've been over this, if it were +40% throughput then IPC gain would be even higher.But the question still remains unanswered: if that really is IPC over EXC they mentioned, or, throughput
Its still faster chip. With more memory, more TFLOPs and cheaper price. It uses 40W more? Well that sucks, but it sucks more if AMD wants to deliver the goods in laptop. If I'm building budget gaming PC I'll take faster card that is more future proof.Despite the concerted effort in these forum to discredit it, power consumption does matter, and Polaris was a dud in this area. It was especially disappointing after all the hype by AMD (and the fans in this forum) about 2.5x performance per watt improvement, how it would beat nVidia in efficiency, blah, blah, blah, when the majority of cards failed to even come close to that. In fact, despite AMD's backtracking that it was for only one model, I dont know if any model ever reached that efficiency. It was also quite entertaining to see all the posts about how wonderful polaris would be in performance per watt, and the desperate backtracking and reversals of field when it turn out nVidia was still more efficient and we were then told to change our light bulbs and quit drinking beer instead of buying an efficient card.
As for CMT yield I used hardware.fr results from their Bulldozer review. I doubt that PD core has any better CMT performance, AMD just upped the IPC of the core by around 7-10% from what I saw in the reviews.
Edit: Are you sure that average CMT yield is the 75%. Hardware.fr found that many MT workloads didn't see more than 50% (or even less than that):
Eliminating all the games(ST) and low score outliers ( like Winrar/1st pass) I get 49% average CMT yield.
That s about the 100th time that such a "question" was answered in this very thread, do you know that we have the info since Hotchips..?.
Of course it is possible to support Raven with 2-phase secondary plane,
Most of the mainstream boards will most likely utilize the new controller family from Intersil, which supports flexible phase configuration.
Okay, I'm curious: how? Do you have to split one plane between the NB and GPU?
Interesting. So those 4+3 boards can commit one extra phase to the CPU for Summit Ridge . . . wait, what's with the extra choke on that Gigabyte board, though?