Sizing Up Servers: Intel's Skylake-SP Xeon versus AMD's EPYC 7000 - The Server CPU Battle of the Decade?
by Johan De Gelas & Ian Cutress on July 11, 2017 12:15 PM EST- Posted in
- CPUs
- AMD
- Intel
- Xeon
- Enterprise
- Skylake
- Zen
- Naples
- Skylake-SP
- EPYC
Intel’s Turbo Modes
A last minute detail from Intel yesterday was information on the Turbo modes. As expected, not all of the processors actually run at their rated/base frequency: most will apply a series of turbo modes depending on how many cores are registered as ‘active’. Each core can have its frequency adjusted independently, allowing VMs to take advantage of different workload types and not be hamstrung by occupants on other VMs in the same socket. This becomes important when AVX, AVX2 and AVX-512 are being used at the same time.
Most of the turbo modes are a sliding scale, with the peak turbo used when only one or two cores are active, sliding down to a minimum frequency that may be the ‘base’ frequency or just above it. There’s a lot of information for the parts here, so we’ll break it down into stages.
First up, a look at the Platinum 8180 in the different modes:
It should be worth noting what the base frequency actually is, and some of the nuance in Intel’s wording here. The base frequency is the guaranteed frequency of the chip – Intel sells the chip with the base frequencies as the guarantee, such that when the chip is not idle and not in normal conditions (i.e. when not in thermal power states to reduce temperature) should operate at this frequency or above it. Intel also lists the per-core turbo frequencies as ‘Maximum Core Frequencies’ indicating that the processors could be running lower than listed, depending on power distribution and requirements in other areas of the chip (such as the uncore, or memory controller). It’s a vague set of terms but ultimately the frequency is determined on the fly and can be affected by many factors, but Intel guarantees a certain amount and provides guides as to what it expects the turbo frequencies to be.
As for the Platinum 8180, it keeps its top turbo modes while up to two cores are active, and then drops down. It does this again for another two cores, and a further two cores. From this point, under non-AVX load the CPU is pretty much the same frequency until >20 cores are loaded, but does not decrease that much in all. For AVX 2.0 and AVX-512, the downward slope of more cores means less frequency continues, with AVX-512 taking a bigger jump down at 13 cores loaded. The final turbo frequency for AVX-512 running on all cores is 2.3 GHz.
Comparing the two 28-core CPUs for which we have turbo information gives this graph. The numbers relate to the number of cores need to be loaded for that frequency.
Both processors are equal to each other for dual core loading, but the separation occurs when more cores are loaded. As we move through to AVX 2.0 and AVX-512, it is clear where the separations are in performance – to get the best for variable core loading, the more expensive processors are required.
Here’s the big table for all the processors on Non-AVX loading:
Despite the 2.0/2.1 GHz base on most of the Platinum series, all the CPUs will turbo up to 3.7-3.8 GHz on low core loading except for the lower power Platinum 8153. For users wanting to strike a good balance between the core count and frequency, the Gold 6154 is probably the place to be: 18 cores that will only ever run at 3.7 GHz with non-AVX loading (3.5-2.7 GHz on AVX-512 depending on core count), and will be $3543 as a list price at 205W. It is perhaps worth noting that this will likely top any of the Core i9 processors planned: at 18-cores and 205W for 3.7 GHz, the Core i9-7980XE which will have 18 cores but run 165W will likely be clocked lower (but also only ~$2000).
Moving onto AVX2.0 and AVX-512:
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Panxa - Sunday, July 16, 2017 - link
"Competition has spoiled the naming convention Intels 14 === competetions 7 or 10"The node naming convention used to be the gate length, however that has become irrelevant. Intel 14 nm gate lenghth is about 1.5x and 10 nm about 1.8x. Companies and organizations have developed quite accurate models to asses process density with equations based on process poarameters like CPP and MPP to what they call a "standard node"
"Intel used to maintain 2 year lead now grew that to 3-4year lead"
Don't belive intel propaganda. Intel takes the lead in 2014 with their 14nm process with a standard node value of 12.1. Samsung and then TSMC take the lead in 2017 with their 10nm processes having standard node values of 11.2 and 10.3 respectively. Intel will retake the the lead back when they deliver their 10nm process with a standard node value of 8.3. However it will be a short lived lead, TSMC will retake the lead back with their 7nm with a standard node of 7.9 before GLOBALFOUNDRIES takes the lead in 2018 with their 7nm process with a standard node value of 7.8. The gap is gone !!!
"yet their revenue profits grow year over year"
Wrong. Intel revenue for the last years remained fairly constant
2011 grow
2012 decline
2013 decline
2014 grow
2015 decline
2016 grow
All in all from 2011 to 2016 revenue went from 54 billion to 59 billion. If we take into account inflation $54 billion in the year 2011 is worth $58.70 billion today.
Not to mention that Samsung has overtaken Intel to become the world No.1 semiconductor company, and that a "pure play" foundry like TSMC has surpassed intel in market CAP
johnp_ - Wednesday, July 12, 2017 - link
The Xeon Bronze Table on Page 7 seems to have an error. It lists the 4112 as having 5.50MB L3, but ark says it has 8.25MB, just like the 3104, so it looks like it has an above-average L3/Core:https://ark.intel.com/products/123551
Ian Cutress - Friday, July 14, 2017 - link
I've got Intel documents from our briefings that say it has the regular 1.375MB/core allocation, and others saying it has 8.25MB. I'm double checking.johnp_ - Friday, July 21, 2017 - link
All commercial listings and most reviews I've seen online show the processor with 8.25MB as well.Do you have any further information from Intel?
pepoluan - Wednesday, July 12, 2017 - link
What I'm dying to know: Performance when running as virtualization host. Using Xen, VMware, and Hyper-V.Threska - Saturday, July 22, 2017 - link
Virtualization itself, and more importantly virtualization security.Sparkyman215 - Wednesday, July 12, 2017 - link
Typo here: Intel will seven different versions of the chipset, varying in 10G and QAT support, but also varying in TDP:tmbm50 - Wednesday, July 12, 2017 - link
One thing to consider when considering value is the Microsoft Server 2016 core tax.....assuming your mission critical apps are still tied to MS ;-)Server 2016 now chargers per core with an 8 core socket as the base. The Window license for a 32 core server is NUTS.
I'm surprised AMD and Intel are not pushing Microsoft on this. For datacenters like ourselves its pushing us to 8 core sku's with more 2U nodes.
msroadkill612 - Wednesday, July 12, 2017 - link
Aye, its a fuuny world lad.The way the automobile panned out differently in different countries, was laargely die to fuel tax regimes, rather than technology.
i.e. what is the best way to cheat a bit on the incumbent tax rules of germany/france/uk vs a more laissez faire USA. In UK, u were taxed on horsepower, but u could cheat a bit w/ hi revs & more gears - that sort of thing.
rahvin - Wednesday, July 12, 2017 - link
Who runs any Windows service on bare metal these days? If you haven't virtulalized your windows servers running on KVM you should.