Analyzing Performance Per Dollar

While measuring the performance per watt is an interesting metric, workstation processors are at the top of the stack when it comes to power consumption: the point of these processors (typically) is getting work done fast, and their users don't mind using a bit more power to get there. When it comes to designing a workstation level system for an office, the person who signs off on the project is not going to look at the performance per watt - they are going to look at the performance per dollar. Does this purchase represent the best value for the environment, and is the purchase likely to give us the best return? The following graphs attempt to answer that information, and we've chosen a varied selection including variable threaded loads.

For this analysis, we've taken all of the processors we have tested from what Intel has launched in 2017. This covers all of the consumer level Kaby Lake-S i7 and i5 parts (except T), the high-end desktop Kaby Lake-X processors, and all the high-end Skylake-X desktop parts. This is represented in the graphs in blue under the 'Intel 2017' title. From AMD, we have all eleven AMD Ryzen processors tested, under the red line.

Compile Performance Per Dollar

One of our popular benchmarks is our compile test. This takes a fixed version of Chromium v56, and runs it through the MSVC compiler with linking as per the directions given on by the Chromium developers. A typical test can run from 40 minutes to 3 hours depending on the processor, and taxes the single thread, the multi-thread and the memory performance of the system. We've seen that it does not particularly take kindly to processors with victim caches, such as Skylake-X or AMD Ryzen, with limited scaling on the code workflow. Despite the per-core performance dip from Skylake-S to Skylake-X, the top processor still has the best absolute performance. Converting our data to the number of compiles per day per dollar gives the following graph:

The cheaper end of the graph is surprisingly high, dominated by Intel's dual-core Pentium (with hyperthreading) being offered for super low prices. In the standard 'consumer' price range below $300, the mid-range Ryzen processors have a slight advantage, but, beyond the Ryzen 7 1700, Intel has the performance per dollar advantage all the way out to $2000.

Agisoft Performance Per Dollar

The Agisoft Photoscan software has been a key part of our performance testing for several years, demonstrating a true office workflow: archival purposes of taking 2D photos and converting them into 3D models. This is a computationally interesting algorithm, involving multiple single-threaded and multi-threaded stages.

Due to the single threaded elements of the algorithm, linear scaling is not observed as we ramp up through the core counts. At the mid-range consumer processor pricing, the twelve-thread Ryzen 5 processors sit above the quad-thread Core i5 parts, but beyond $330 or so, as we move into Intel's quad-core offerings and above, the performance per dollar is solely on Intel's side.

Blender Performance Per Dollar

The Blender benchmark has been an interesting debate in the last few months, with the new architectures from Intel and AMD pushing updates into the code for faster rendering. Our test takes a well used Blender release and one of the standard benchmarks (rather than anything vendor specified). Results are given in renders of this benchmark per day per dollar.

Interestingly AMD takes the peak PPD across the full range. At $999, where the competition is expected to be highest, AMD has over a 10% advantage. In the four digit range, even though the PPD of Intel's processors is lower, the absolute performance is still better. For our Blender test, this translates so a few seconds over a 2-3 minute test.

Cinebench R15 nT Performance Per Dollar

Next we move into the pure multithreaded benchmarks, which can be a significant number of workstation workloads. Here Intel might be at a disadvantage, with AMD offering more cores and more threads at each price point - Intel's IPC advantage will have to offset this in order to move ahead.

To lay some background here: AMD has been plugging Cinebench R15 nT benchmark numbers since the launch of Zen, citing better PPD. Intel's rebuttal is that in absolute performance, when you need the absolute best results, their hardware still wins.

Corona Rendering Performance Per Dollar

Ray tracing is another example of light threads taking advantage of more cores, more frequency, higher IPC and accelerated intructions with fast FP throughput. Citing back to Johan's EPYC review again, which showed AMD's good base FP performance, it will be an interesting comparison.

Similar to some of the previous graphs, the best PPD is held at Intel's low end Pentium processors - however these do not give the best overall throughput. In the mainstream price range, the Ryzen 5 1600 and 1600X are suprising peak results. In the $500-$800 range, Intel and AMD are about equal, however at $999 the Threadripper is ahead of the Core i9. Again, at the $1500+ range, Intel offers the better overall throughput, despite the lower PPD.

Power Consumption and Power Efficiency Intel Core i9-7980XE and Core i9-7960X Conclusion
Comments Locked

152 Comments

View All Comments

  • extide - Monday, September 25, 2017 - link

    No, TDP should include Turbo as that is part of the base/stock operation mode of the CPU.
  • IGTrading - Monday, September 25, 2017 - link

    TDP = Total Design Power by definition.

    This is used to design the motherboard and the cooling system to give designers a clear limit over which the system doesn't go unless it is purposely overcloked.

    Wikipedia : "The thermal design power (TDP), sometimes called thermal design point, is the maximum amount of heat generated by a computer chip or component (often the CPU or GPU) that the cooling system in a computer is designed to dissipate under any workload."

    Intel : "TDP (Thermal Design Power) Intel defines TDP as follows: The upper point of the thermal profile consists of the Thermal Design

    Power (TDP) and the associated Tcase value. Thermal Design Power (TDP) should be used for
    processor thermal solution design targets. TDP is not the maximum power that the processor can
    dissipate. TDP is measured at maximum TCASE.1"

    Intel : "Due to normal manufacturing variations, the exact thermal characteristics of each individual processor are unique. Within the specified parameters of the part, some processors may operate at a slightly higher or lower voltage, some may dissipate slightly higher or lower power and some may draw slightly higher or lower current. As such, no two parts have identical power and thermal characteristics.

    However the TDP specifications represent a “will not exceed” value. "

    This is what we've understood by TDP in the past 21 years while in IT hardware industry.

    If you have a different definition, then perhaps we're talking about different things.
  • whatevs - Monday, September 25, 2017 - link

    Specification for 7980xe says "Thermal Design Power (TDP) represents the average power, in watts, the processor dissipates when operating at Base Frequency with all cores active under an Intel-defined, high-complexity workload. Refer to Datasheet for thermal solution requirements."
    There's a different specification for electrical design. This is not your ancient Xeon TDP.
  • IGTrading - Monday, September 25, 2017 - link

    You mean the definition of TDP should change every year to suit Intel's marketing ?! :)

    "Ancient" Xeon TDP ?! :)

    I've quoted Intel's own definition.

    If the company just came up with a NEW and DIFFERENT definition just for the Core i9 series, then that's just plain deceiving marketing, changing with the wind (read : new generation of products) .

    Plus, why the heck are they calling it TDP ?!

    If they now claim that TDP "represents the average power, in watts, the processor dissipates when operating at Base Frequency with all cores active " then they basically use AMD's ACP from 2011.

    What a load of nonsense from Intel ...

    https://www.intel.com/content/dam/doc/white-paper/...
  • whatevs - Monday, September 25, 2017 - link

    You have quoted 6 year old Xeon definition, different products have different operating conditions, deal with it.
  • Spunjji - Monday, September 25, 2017 - link

    Your name suggests that you're kind of a dick and your comments confirm it. Your point is weak and doesn't at all do the work you think it does.
  • whatevs - Monday, September 25, 2017 - link

    You may be unhappy with what Intel promised you, but to claim that you could burn a system with increased power usage from turbo clocks is ridiculous, thermal throttling is not fire, and it's ridiculous to argue on a cpu that can run overclocked at >400w power consumption.
  • Notmyusualid - Monday, September 25, 2017 - link

    +1
  • wolfemane - Tuesday, September 26, 2017 - link

    You can't talk rationale with a loyalist sympathizer. TDP is a set definition in the industry and one Intel seems to be misleading about with their Extreme HEDT CPU. That seems to be a fact clearly made among almost all reviews of the 7980xe.

    I think I read a few articles yesterday talking about how the 7980xe was having major issues and wasn't boosting correctly but showing high power draw. But yesterday was a long time ago and I cant remember where I read that.
  • someonesomewherelse - Saturday, October 14, 2017 - link

    So why not call it 'Average Design Power - ADP'?

Log in

Don't have an account? Sign up now