A Broadwell Retrospective Review in 2020: Is eDRAM Still Worth It?
by Dr. Ian Cutress on November 2, 2020 11:00 AM ESTPower Consumption
The nature of reporting processor power consumption has become, in part, a dystopian nightmare. Historically the peak power consumption of a processor, as purchased, is given by its Thermal Design Power (TDP, or PL1). For many markets, such as embedded processors, that value of TDP still signifies the peak power consumption. For the processors we test at AnandTech, either desktop, notebook, or enterprise, this is not always the case.
Modern high performance processors implement a feature called Turbo. This allows, usually for a limited time, a processor to go beyond its rated frequency. Exactly how far the processor goes depends on a few factors, such as the Turbo Power Limit (PL2), whether the peak frequency is hard coded, the thermals, and the power delivery. Turbo can sometimes be very aggressive, allowing power values 2.5x above the rated TDP.
AMD and Intel have different definitions for TDP, but are broadly speaking applied the same. The difference comes to turbo modes, turbo limits, turbo budgets, and how the processors manage that power balance. These topics are 10000-12000 word articles in their own right, and we’ve got a few articles worth reading on the topic.
- Why Intel Processors Draw More Power Than Expected: TDP and Turbo Explained
- Talking TDP, Turbo and Overclocking: An Interview with Intel Fellow Guy Therien
- Reaching for Turbo: Aligning Perception with AMD’s Frequency Metrics
- Intel’s TDP Shenanigans Hurts Everyone
In simple terms, processor manufacturers only ever guarantee two values which are tied together - when all cores are running at base frequency, the processor should be running at or below the TDP rating. All turbo modes and power modes above that are not covered by warranty. Intel kind of screwed this up with the Tiger Lake launch in September 2020, by refusing to define a TDP rating for its new processors, instead going for a range. Obfuscation like this is a frustrating endeavor for press and end-users alike.
However, for our tests in this review, we measure the power consumption of the processor in a variety of different scenarios. These include full AVX2/AVX512 (delete as applicable) workflows, real-world image-model construction, and others as appropriate. These tests are done as comparative models. We also note the peak power recorded in any of our tests.
In peak power, the Core i7-5775C sticks to the 65 W value, whereas the Core i5 variant is below its TDP value. This is beyond the 22nm Core i7-4790S which is also a 65 W part.
In real-world tests, first up is our image-model construction workload, using our Agisoft Photoscan benchmark. This test has a number of different areas that involve single thread, multi-thread, or memory limited algorithms.
For Photoscan, the Core i7 spends its 'real world' time around 60 W, but does momentarily spike up above that 60 W mark. The Core i5 by comparison doesn't even touch 50 W.
The second test is from y-Cruncher, which is our AVX2/AVX512 workload. This also has some memory requirements, which can lead to periodic cycling with systems that have lower memory bandwidth per core options.
We're seeing some slight variation in power as the y-Cruncher algortihm moves out to DRAM movement over compute, however both processors seem to be hitting either their power limits or just a natural peak power consumption.
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dsplover - Tuesday, November 3, 2020 - link
For Digital s Audio applications the i7-5775C @ 3.3GHz was incredible when disabling the Iris GFX turning the cache over to audio, then running s discrete GFX card.Bested my i7 4790k’s.
Tried OC’ing but even with the kick but Supermicro H70 it was unstable as the Ring Bus/L4 would also clock up and choked @ 2050MHz.
This rig allowed really tight low latency timings and I prayed they would release future designs with a larger cache.
AMD beat them to to it w/Matisse which was good for 8 core only.
The new 5000s are going to be Digital Audio dreams @ low wattage.
Intel just keeps lagging behind.
ironicom - Tuesday, November 3, 2020 - link
fps is irrelevant in civ; turn time and load time are what matter.vorsgren - Tuesday, November 3, 2020 - link
Thanks for using my benchmark! Hope it was usefull!Nictron - Wednesday, November 4, 2020 - link
Which benchmark was that?erotomania - Wednesday, November 4, 2020 - link
Google the username.vorsgren - Wednesday, November 4, 2020 - link
http://www.bay12forums.com/smf/index.php?topic=173...Oxford Guy - Thursday, November 5, 2020 - link
"The Intel skew on this site is getting silly its becoming an Intel promo machine!"Yes. An article that exposes how much Intel was able to get away with sandbagging because of our tech world's lack of adequate competition (seen in MANY tech areas to the point where it's more the norm than the exception) — clearly such an article is showing Intel in a good light.
If you were an Intel shareholder.
For everyone else (the majority of the readers), the article condemns Intel for intentionally hobbing Skylake's gaming performance. ArsTechnica produced an article about this five years ago when it became clear that Skylake wasn't going to have EDRAM.
The ridiculousness of the situation (how Intel got away with charging premium prices for horribly hobbled parts — $10 worth of EDRAM missing, no less) really shows the world's economic system particularly poorly. For all the alleged capitalism in tech, there certainly isn't much competition. That's why Intel didn't have to ship Skylake with EDRAM. Monopolization (and near-monopoly) enables companies to do what they want to do more than anything else: sell less for more. As long as regulators are toothless and/or incompetent the situation won't improve much.
erikvanvelzen - Saturday, November 7, 2020 - link
Ever since the Pentium 4 Extreme Edition I've wondered why intel does not permanently offer a top product with a large L3 or L4 cache.abufrejoval - Monday, November 9, 2020 - link
Just picked up a NUC8i7BEH last week (quad i7, 48EU GT3e with 128MB eDRAM), because they dropped below €300 including VAT: A pretty incredible value at that price point and extremely compatible with just about any software you can throw at it.Yes, Tiger Lake NUC11 would be better on paper and I have tried getting a Ryzen 7-4800U (as PN50-BBR748MD), but I've never heard of one actually shipped.
It's my second NUC8i7BEH, I had gotten another a month or two previously, while it was still at €450, but decided to swap that against a hexa-core NUC10i7FNH (24EU no eDRAM) at the same price, before the 14-days zero-cost return period was up. GT3e+quad-core vs. GT2+hexa-core was a tough call to make, but acutally both run really mostly server loads anyway. But at €300/quad vs €450/hexa the GT3e is quite simply for free, when the silicon die area for the GT3e/quad is in all likelyhood much greater than for the GT2/hexa, even without counting the eDRAM.
My Whiskey-lake has 200MHz less top clock than the Comet-lake, but that doesn't show in single core results, where the L4 seems to put Whiskey consistently into a small lead.
GT3e doesn't quite manage to double graphics performance over GT2, but I am not planning to use either for gaming. Both do fairly well at 4k on anything 2D, even Google Map's 3D renders do pretty well.
BTW: While Google Earth Pro's Flight simulator actually gives a fairly accurate representation of the area where I live, it doesn't do great on FPS, even with an Nvidia GPU. By contrast Microsoft latest and greatest is a huge disappointment when it comes to terrain accuracy (buildings are pure fantasy, not related at all to what's actually there), but delivers ok FPS on my RTX2080ti. No, I didn't try FlightSim on the NUCs...
However, the 3D rendering pipeline Google has put into the browser variant of Google Maps, beats the socks off both Google Earth Pro and Microsoft Flight: With Chrome leading over Firefox significantly, the 3D modelled environment is mind-boggling even on the GT2 at 4k resolutions, it's buttery smooth on GT3e. A browser based flight simulator might actually give the best experience overall, quite hard to believe in a way.
It has me appreciate how good even iGPU graphics could be, if code was properly tuned to make do with what's there.
And it exposes just how bad Microsoft Flight is with nothing but Bing map data unterneath: Those €120 were a full waste of money, but I just saved those from buying the second NUC8 later.
mrtunakarya - Wednesday, December 9, 2020 - link
<a href="https://www.mrtunakarya.com/?m=1">Nice<...