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Up until around 2012, realworldtech.com and anandtech.com used to publish rather more detailed descriptions of the microarchitecture inside each core. Is anyon

Up until around 2012, realworldtech.com and anandtech.com used to publish rather more detailed descriptions of the microarchitecture inside each core. Is anyone publishing things like that these days? I mean pages like these: https://www.realworldtech.com/haswell-cpu/4/ https://www.realworldtech.com/haswell-cpu/4/ https://www.anandtech.com/show/6355/intels-haswell-architecture/8 https://www.anandtech.com/show/6355/intels-haswell-architect... (I noticed that Agner Fog's chapter on Ryzen is conspicuously missing a "Literature" section.)

throwaway2048 7y ago
The servethehome review of Rome is a pretty detailed look at the architecture. https://www.servethehome.com/amd-epyc-7002-series-rome-delivers-a-knockout/ https://www.servethehome.com/amd-epyc-7002-series-rome-deliv...
rrss 7y ago
https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome/ https://www.anandtech.com/show/14525/amd-zen-2-microarchitec...
- mjw1007 7y ago
  That, and the servethehome review, seems to be basically putting the presentation slides into words. A few years ago they seemed to have additional sources of information (they'd talk about things like instruction-to-port assignments and penalties for moving data between integer and FP domains).
  - rrss 7y ago
    Maybe one of the write ups of AMD's presentation at hot chips next week will have what you want. To be honest, though, I don't see a substantial difference between the haswell article you linked and the Zen 2 article, provided you are willing to look past the AMD slides. The haswell article is also just "putting the presentation slides into words," just from IDF 2012 instead of AMD Tech Day 2019, and apparently the author felt a need to do the block diagrams themselves. (Also, FWIW, Agner's manual does have a literature section for Ryzen, it is just not numbered for some reason).
  - galaxyLogic 7y ago
    Maybe that means that the AMD presentation slides are pretty good? Beyond that it gets into pretty deep expertise into both Intel and AMD for comparison of the approaches and I assume most such high-level experts works for either AMD or Intel so you would not get an impartial view anyway
Quequau 7y ago
I despair that the market is more interested in things like mobile apps and LED equipped RAM than serious in-depth technical reporting on microprocessor internals.
ksec 7y ago
Anandtech still does that, just no longer written by Anand himself ( He is working in Apple now ). So the writing aren't as good. Even though the technical details are still there. One of the problem is that the market for these kind of review are very much a niche. And just like all forms of free media, if there aren't enough page view they stop doing it. I have always thought some of these media will consolidate, I mean I only ever read Anandtech, Servethehome and some Ars, and that is about it. I have RSS Header news feed from a few other sources such as Tom's hardware, Engadget but if Anandtech cover the same topic I always go there first. Not only has that not happen, most of these website manage to stay afloat catering for different market. But I have no idea how the market segmentation works. I could tell site like Wcctech is sort of 100% rumours site with very little if any technical knowledge in writing. And yet it gathers huge amount of audience. While others like Tom's Hardware seems to have retain enough of its news reader to become sustainable.
- close04 7y ago
  Unfortunately while AT still has some great deep-dives for mobile SoCs (top marks to Andrei Frumusanu), the x86 articles have become a bit shallow. And if that wasn't bad enough, they also suggest some bias. They tend to bang the drum when it comes to Intel but in AMD reviews you'll get things like "Due to bad luck and timing issues we have not been able to test the latest Intel and AMD servers CPU in our most demanding workloads". It's a lot like reviewing a Ferrari but due to bad luck you could only test it in city traffic. 2 years ago they forgot to cover the Threadripper launch for 2 weeks while the front page was flooded with dozens of uninteresting half page articles about Intel motherboards being launched around the same time. I love a good tech article regardless of which brand they're talking about but bias will always kill the experience for me. YMMV I guess.
  - toast0 7y ago
    From watching these sites for years, I think you can see whatever bias you want to see. Some sites/authors do have clear bias, but a lot of it is just time pressure. Often, review parts are shipped to sites with a review embargo until a certain date -- if you don't ship your review on that date, you lose out; if the shipment is late because of the vendor, or the shipping service, or the reviewer is sick, or out of town, or the shipped firmware isn't great and interim firmware makes a big difference the choices are: a) take the time to do a full review, but publish late b) do a cursory review, apologize and publish on time c) do b, but follow up with a full review as time permits If C happens more with AMD than Intel, it could be bias, it could be bad luck, or it could be Intel has been delivering more finished things to reviewers.
ENOTTY 7y ago
Wikichip is my go-to for these things.
deepnotderp 7y ago
Wikichip is nice, but tbh a lot of this stuff ends up in analyst reports nowadays. Look at conference proceedings if you're interested
twotwotwo 7y ago
I think the tech press still tells us what they can, and stuff like execution ports, reorder windows, etc. is still publicly disclosed. AT talked about what was publicly said about Zen 2 (https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome https://www.anandtech.com/show/14525/amd-zen-2-microarchitec...) and Sunny Cove (https://www.anandtech.com/show/14514/examining-intels-ice-lake-microarchitecture-and-sunny-cove https://www.anandtech.com/show/14514/examining-intels-ice-la...). And their reviews do try to report the top observable results (memory latencies, relative performance on different kinds of task, power/clock info) and all that's arguably of more practical importance to lots of folks anyway. There's also just the trend of modern designs being tricky enough it's harder to infer as much about them and harder to write accessibly about what you do know; it's not super easy to figure out and describe, say, modern branch predictors simply because they're all layering a lot of strategies on each other. For example, from Haswell on, Agner Fog essentially said Intel's large-core branch predictors are good at lots of things but there's not much he can say about how they work (p29 at https://www.agner.org/optimize/microarchitecture.pdf https://www.agner.org/optimize/microarchitecture.pdf). Writing code to beat Cortex-A76 prefetchers, AT's Andrei Frumusanu had difficulty fooling them with anything other than essentially-random access patterns and compared them to "black magic" (https://twitter.com/andreif7/status/1102230575522430977 https://twitter.com/andreif7/status/1102230575522430977). These aren't just random folks saying "wow, CPUs are complicated"; they successfully figured lots of stuff about past generations of CPU. AMD did reference the TAGE family of branch predictors, which there's lots about in public literature. There might be some broadly interesting stuff in the vendors' contributions to gcc/LLVM (machine models and arch-specific optimizations). Maybe ARM implementors talk a little more about their stuff? That might have something to do with the dynamics of the relatively open/diverse market for ARM SoCs versus the long-running one-on-one-ish x86 rivalry. Hard to boil all that down to a single point, but if AMD and Intel want to talk more about the guts of their products, I'm sure plenty of grateful wonks would lap it up. :)

throwaway2048 7y ago

The servethehome review of Rome is a pretty detailed look at the architecture. https://www.servethehome.com/amd-epyc-7002-series-rome-delivers-a-knockout/ https://www.servethehome.com/amd-epyc-7002-series-rome-deliv...

rrss 7y ago

https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome/ https://www.anandtech.com/show/14525/amd-zen-2-microarchitec...

mjw1007 7y ago
That, and the servethehome review, seems to be basically putting the presentation slides into words. A few years ago they seemed to have additional sources of information (they'd talk about things like instruction-to-port assignments and penalties for moving data between integer and FP domains).
- rrss 7y ago
  Maybe one of the write ups of AMD's presentation at hot chips next week will have what you want. To be honest, though, I don't see a substantial difference between the haswell article you linked and the Zen 2 article, provided you are willing to look past the AMD slides. The haswell article is also just "putting the presentation slides into words," just from IDF 2012 instead of AMD Tech Day 2019, and apparently the author felt a need to do the block diagrams themselves. (Also, FWIW, Agner's manual does have a literature section for Ryzen, it is just not numbered for some reason).
- galaxyLogic 7y ago
  Maybe that means that the AMD presentation slides are pretty good? Beyond that it gets into pretty deep expertise into both Intel and AMD for comparison of the approaches and I assume most such high-level experts works for either AMD or Intel so you would not get an impartial view anyway

Quequau 7y ago

I despair that the market is more interested in things like mobile apps and LED equipped RAM than serious in-depth technical reporting on microprocessor internals.

ksec 7y ago

Anandtech still does that, just no longer written by Anand himself ( He is working in Apple now ). So the writing aren't as good. Even though the technical details are still there. One of the problem is that the market for these kind of review are very much a niche. And just like all forms of free media, if there aren't enough page view they stop doing it. I have always thought some of these media will consolidate, I mean I only ever read Anandtech, Servethehome and some Ars, and that is about it. I have RSS Header news feed from a few other sources such as Tom's hardware, Engadget but if Anandtech cover the same topic I always go there first. Not only has that not happen, most of these website manage to stay afloat catering for different market. But I have no idea how the market segmentation works. I could tell site like Wcctech is sort of 100% rumours site with very little if any technical knowledge in writing. And yet it gathers huge amount of audience. While others like Tom's Hardware seems to have retain enough of its news reader to become sustainable.

close04 7y ago
Unfortunately while AT still has some great deep-dives for mobile SoCs (top marks to Andrei Frumusanu), the x86 articles have become a bit shallow. And if that wasn't bad enough, they also suggest some bias. They tend to bang the drum when it comes to Intel but in AMD reviews you'll get things like "Due to bad luck and timing issues we have not been able to test the latest Intel and AMD servers CPU in our most demanding workloads". It's a lot like reviewing a Ferrari but due to bad luck you could only test it in city traffic. 2 years ago they forgot to cover the Threadripper launch for 2 weeks while the front page was flooded with dozens of uninteresting half page articles about Intel motherboards being launched around the same time. I love a good tech article regardless of which brand they're talking about but bias will always kill the experience for me. YMMV I guess.
- toast0 7y ago
  From watching these sites for years, I think you can see whatever bias you want to see. Some sites/authors do have clear bias, but a lot of it is just time pressure. Often, review parts are shipped to sites with a review embargo until a certain date -- if you don't ship your review on that date, you lose out; if the shipment is late because of the vendor, or the shipping service, or the reviewer is sick, or out of town, or the shipped firmware isn't great and interim firmware makes a big difference the choices are: a) take the time to do a full review, but publish late b) do a cursory review, apologize and publish on time c) do b, but follow up with a full review as time permits If C happens more with AMD than Intel, it could be bias, it could be bad luck, or it could be Intel has been delivering more finished things to reviewers.

ENOTTY 7y ago

Wikichip is my go-to for these things.

deepnotderp 7y ago

Wikichip is nice, but tbh a lot of this stuff ends up in analyst reports nowadays. Look at conference proceedings if you're interested

twotwotwo 7y ago

I think the tech press still tells us what they can, and stuff like execution ports, reorder windows, etc. is still publicly disclosed. AT talked about what was publicly said about Zen 2 (https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome https://www.anandtech.com/show/14525/amd-zen-2-microarchitec...) and Sunny Cove (https://www.anandtech.com/show/14514/examining-intels-ice-lake-microarchitecture-and-sunny-cove https://www.anandtech.com/show/14514/examining-intels-ice-la...). And their reviews do try to report the top observable results (memory latencies, relative performance on different kinds of task, power/clock info) and all that's arguably of more practical importance to lots of folks anyway. There's also just the trend of modern designs being tricky enough it's harder to infer as much about them and harder to write accessibly about what you do know; it's not super easy to figure out and describe, say, modern branch predictors simply because they're all layering a lot of strategies on each other. For example, from Haswell on, Agner Fog essentially said Intel's large-core branch predictors are good at lots of things but there's not much he can say about how they work (p29 at https://www.agner.org/optimize/microarchitecture.pdf https://www.agner.org/optimize/microarchitecture.pdf). Writing code to beat Cortex-A76 prefetchers, AT's Andrei Frumusanu had difficulty fooling them with anything other than essentially-random access patterns and compared them to "black magic" (https://twitter.com/andreif7/status/1102230575522430977 https://twitter.com/andreif7/status/1102230575522430977). These aren't just random folks saying "wow, CPUs are complicated"; they successfully figured lots of stuff about past generations of CPU. AMD did reference the TAGE family of branch predictors, which there's lots about in public literature. There might be some broadly interesting stuff in the vendors' contributions to gcc/LLVM (machine models and arch-specific optimizations). Maybe ARM implementors talk a little more about their stuff? That might have something to do with the dynamics of the relatively open/diverse market for ARM SoCs versus the long-running one-on-one-ish x86 rivalry. Hard to boil all that down to a single point, but if AMD and Intel want to talk more about the guts of their products, I'm sure plenty of grateful wonks would lap it up. :)