Monday, August 22, 2016

Two days to go until AMD's Hot Chips presentation - how about Zen's core size?

TL;DR: Zen's many integer schedulers might be related to dedicated dependency chain handling. And the Zen core might be just 4.9 mm² incl. L2 cache.

Here are some last speculative thoughts before we'll hear about Zen at Hot Chips 28, from the guy, who told you first about Bulldozer's and Zen's microarchitectures, AMD's upcoming 32 core server chip, and some other interesting things. Now I can say this, as AMD did present a first view on Zen's microarchitecture just a day after my last blog posting. Again, I was pretty close. This simply depends on the amount of data found in patches and patents.

However, some things are different: The speculated Zen microarchitecture shown here on this blog had a unified scheduler for the 4 ALUs and a second one for the AGUs, while Zen actually has 6 separate schedulers instead. The base for my assumption was the cat core heritage. But of course, a unified scheduler for 4 execution units holding lots of µOps is still a big step up from a scheduler, which only has to issue to two units (cat cores). Now what's the reason for this configuration? At first, there are many possible typical design trade-off related reasons, like area, delays, buffer sizes, power efficiency. But there are also some interesting concepts, like a dependency chain oriented handling of instruction streams. If some code has an instruction level parallelism greater than one, there are groups of instructions, which at some point could be executed independently of the main flow, until their result gets fed back. These groups and sections of the main flow could also be called dependency chains, where it is not possible to execute a newer instruction before an older one, as each of them in the chain depends on some result of its predecessing operation. Here is an example:
mov eax, [edi]
add eax, ecx
imul edi, eax
cmp [ebp+08h], edi
jnz out
This code actually can't be executed out-of-order. All the logic put into an out-of-order scheduler would be a waste of energy in this case. And multiple same type execution units for parallel issue wouldn't help to speed this up either. A single scheduler with an integer execution unit (IEU), and an address generation unit (AGU) would be enough. The latter wouldn't even need a separate scheduler, similar to the K7, K8, K10 series of CPUs. This could be one reason for Zen's individual schedulers, as one identified dependency chain could be sent to a single integer scheduler and one AGU scheduler if there are memory operands. The other schedulers might even be clock gated then.

U.S. Patent No. 8769539 covers a scheduler, which can be switched between out-of-order and in-order operation. One of the inventors is Zen project leader Suzanne Plummer, while Dan Hopper is also an important member of the Zen x86 core design team. In combination with many other patents (for example  US20120023314), which cover dependency chain related logic, there might be such a scheduler in Zen.

Knowing the dependency chain also offers several efficiency measures. One patent covered different latencies for "far source operands" and close ones, i.e. coming from a different "lane" or the same. Bypass networks could be implemented in a somewhat more relaxed way, which improves delay and power efficiency.

A Zen core size estimation

After talking about Zen's die size just days ago, there is another size, which likely will be revealed at Hot Chips: the size of a Zen core. Earlier this year I created a table to estimate that size based on Excavator module components and some scaling factors. Based on AMD's statement about a density optimized process, one of the unknowns in this calculation just became a bit smaller. Their statement could both mean dense metal layers or high density standard cell libs. For simplicity and lack of further data, assuming no density related scaling should do. Process related scaling is a different story, though.

Using die photos, it is possible to measure the size of a graphics CU. On a Polaris 10 die, the size of a graphics CU is about 2.96 mm², while Carrizo has 7.21 mm² CUs. This results in a scaling factor of about 41%. Putting this all together with some individual scaling factors based on design changes (e.g. more ALUs, smaller multiplier arrays, 64KB L1 I$ - already included in the "area 1C" number), results in a Zen core size incl. L2 cache of about 4.9 mm².

Zen core size estimation based on Excavator data

38 comments:

Arnawa Widagda said...

http://www.pcgameshardware.de/AMD-Zen-Codename-261795/Specials/Architekturdetails-Benchmark-IPC-1205041/galerie/2625556/

Dresdenboy said...

Yep, just hours after my posting. It seems, only German media published them, BTW.

Arnawa Widagda said...

Probably cause it's early in the week.
I do wish there were more details about the front end, but I can understand if AMD decided not go into details at this moment.
Care to write up an analysis on the front end? Looks far more interesting than the execution parts.

Unknown said...

Matthias,
can you do an overall post with all the info we know about Zen till now?Where Zen will lack and where will shine against Intel CPU´s.
I think the lack of 256SIMD will have a big impact on power consumption and the fast cache will deliver a great performance, but I fear the expectations are going sky high.

Tacit Murky said...

«This code actually can't be executed out-of-order» — except for loading this [ebp+08h] argument.

Generally, I think 6 RS's is a bad idea. A core would have less opportunity to issue ready mops to execution; while power-saving can be attained with less sectioning of RS's. Practically, upgraded Cat's version would've be fine: data RS (4 ports), AG/stack RS (2 ports), flags/jumps RS (1 port). Two later ones can be unified in a 3-ported RS. Then it'll be possible to execute float/vector code without waking up large data RS.

128-bit paths for vectors seems degrading. This will have negative effect for both speed and power for all AVX code. It's just repeating one of many BD mistakes…

Jeffry Falzone said...

There has been more of the possible grounds and the values been emphasized in advance and surely for the future would lay down a better platform. java programming help

Lavern Galipeau said...

Hopefully the concerning objects would possibly allow students regarding all those prospects which must have been initiated by them to proceed further. See outsourcing for further assistance

Danish Khalid said...

Here are some last theoretical musings previously we'll catch wind of Zen at Hot Chips 28, from the person, who disclosed to you first about Bulldozer's and Zen's microarchitectures, AMD's up and coming 32 center server chip, and some other fascinating things. Presently I can state this, as AMD presented a first view on Zen's Java Assignment Help | JavaHelpOnline.com only a day after my last blog posting. Once more, I was truly close. This essentially relies upon the measure of information found in patches and licenses.Intellij Homework Help

James Cameron said...

Much gratitude to you such an incredible sum for sharing! I will form a post soon about continuing with your direction. Memorize Quran

Michael Jones said...

• Assignments are often considered the burden on the mind of students not giving them ample time for any other activities. Lack of time denies students from performing their beloved hobbies, ceasing them from participating in any sports, cultural affairs. Hence, no overall growth for them. Online Assignment help

Unknown said...

I just want you to know, that when I picture myself happy, it’s with you wedding anniversary quotes

Dylan Eales said...

Thanks for this informative content. It’s really good. Actually, I want to share some thoughts and reviews about an Australian assignment help company in Australia and the brand name is SAMPLE ASSIGNMENT. Here, I am working as an Academic Expert. To look at our online academic assistants who provide reference assignment including Accounting, Management, Finance, IT, Economics, Computer Science, Nursing, Marketing; all Academic subjects to University Students all over the Australia or even worldwide, Here is a big online assignment help providers who help students to get HD grades according to assessment guidelines and instructions. Those who are searching fo assignment help Melbourne, Perth, Brisbane, Adelaide etc. get a touch with Sample Assignment - the No.1 Assignment provider. Any student really wants to buy an assignment at the cheapest price goes to our branded website and has a look and opts our amazing and informative services, you can avail of our convenient online assignment help and samples available on our website for free. You can download it if you want. Are you ready to get 100 out of 100 in your university assessment? We assign the best writer according to the subject for your academic problems and provide support in assignment writing services. Our Customer Care Executives are available 24*7 hours to assist you in the best possible manner. Phone calls and emails are the best methods used by online assignment maker.

Kartik said...

I might not be your “little man” anymore, but you still have all my love
motherdayquotesi.com
happy mothers day 2019
happy mother day quotes

Maria Garcia said...

Whenever I came across any difficulty, I often used to search “who can do my assignment for me”, but, later on realised that there are many these type of services who promises a lot but does only a little. However, My Assignment Services is one such assignment provider who believe only in the quality. They are exactly the type of assignment service provider that I needed from a long time. By opting their services, you get assistance to a lot of subjects including their nursing assignment help, management, law, engineering, finance, economics, accounting, and a lot more. Therefore, you need not to be worry, instead go for My Assignment Services by visiting the link.

Max Willor said...

I suggest everyone to choose Assignment Help Australia for getting the best guidance in their academia. The proficient experts assist as per the requirements and learning styles desired by the university.

Dan Smith said...

Thanks for posting this info. I just want to let you know that I just check out your site and I find it very interesting and informative. I can't wait to read lots of your posts. If you're looking for CDR Report Help. You can email us at cs@needcdrreport.com or Phone Number: +61-2-8005-8227

Ideal Assignment Help said...

We provide MYOB Assignment Help facilitate at a value that’s very affordable and students friendly. we forever deliver on time and with no excuses! MYOB has an accounting software system that helps businesses to manage finances, save time, and helps the business stay up to date with regulations and obligations. . Our MYOB assignment help is done in record time and delivered to you before your due date. So if you need and you have get help then don't go here and there you have simply visit our website and contact our expert team.

Olivia Crew said...

Excellent information Providing by your Article, thank you for taking the time to share with us such a nice article. Amazing insight you have on this, it's nice to find a website that details so much information about different artists. Kindly visit the LiveWebTutors website we providing the best assignment help services in Australia.

for more info: University Assignemnt Help

john amber said...

Hello… Interesting blog, this blog is very nice and good knowledge. If you are looking for the assignment help and Computer Science Assignment Help service provider then you should definitely go for FirstAssignmentHelp.

belly boys said...

Kareer konncect is a leading software training institute providing Software Training, Project Guidance, IT consulting and Technology Workshops. Using our enhanced global software training delivery methodology, innovative software training approach and industry expertise, we provide high-value corporate training services that enable our clients to enhance business performance, accelerate time-to-market, increase productivity and improve customer service. More Info- Training and Placements

abcassignmenthelp said...

ABC Assignment help provides best Machine learning assignment help service through professional computer science experts. You can learn about any area of machine learning like supervised learning, unsupervised learning, predictive models, regression models, clustering etc. from our experienced tutors. Our services come at an affordable cost making it possible for you to score high in assessments related to optimization methods, clustering algorithms, ensemble learning, deep learning, decision tree, gradient boosting or any other area of machine learning. Connect with one of our experts 24x7 to discuss your machine learning topic and project and start the unique experience of customized assignment help.

Twinkle said...

Nice post. It is really interesting. Thanks for sharing the post!
Web Design Company in Tuticorin | Domain Name Registration In India
Web Design Company In India | Digital Marketing Company in India
PPC Services in India | SEO Company India
Bulk SMS Service in India | Social Media Marketing Company in India

Assignment Help Australia said...

Assignment Help services is the best option for those students who find difficult to manage their assignment within the given date. Complete your assignment before the due dates using Australian writers' assistance at any time
My Assignment Help
Assignment Help Online
Online Assignment Help

printersupportnumber said...

Nice Post..
It is the common problem with the printers that when there is any issue stuck, then back to the offline mode. If you are facing the same problem and looking for the ultimate guide related to how to get printer online, then you are landed in the right place. With the aid of our experts, you can again get your printer in the online mode that even in a short time. Don’t worry, printers go to the offline mode but getting them back to online mode is possible. Don’t stress out and take our help.
hp envy 4500
hp envy 4500 driver
hp envy 4500 printer
hp envy 4500 software
hp 4500 printer
how to turn printer online
how to make printer online
how to get a printer online

masonlava said...

While printing the necessary documents through HP printer, my HP printer goes offline mode. I am applying printing command to my printing device again, and again, my printing machine is showing offline status. HP Printer Offline is one of the most difficult problems, which is preventing me to print the documents in the simple ways. Hence, I want to bring back my printing machine from offline to online mode successfully. But I am getting some technical issues in this process. So please anyone can recommend the quick fixes to rectify HP printer offline error

HP Printer Troubleshooting said...

Software and drivers are the main part of every digital electronic device. Some software helps to manage device to run it smoothly. If you are an HP device user then you should avail HP Assistant to manage and troubleshoot your HP device. This software is very reliable and functional to easily manage HP devices.

ضيافة الكويت said...

لا تترك مجالا للتردد والحيره إذا كنت تريد شركة تقدم لك خدمة ضيافة متكاملة بأرقى الطرق فى مناسباتك السارة مثل كتب كتاب , تخرج , اعياد ميلاد ,وايضا يمكننا توفير تأجير طاولات مضيئة ,وكما فى حالات العزاء تقدم شركتنا خدمة تأجير كراسي للعزاء وايضا المشروبات مثل الشاى والقهوه بطريقة منظمة بواسطة فريق لديه خبرات في هذا المجال بأقل الأسعار وبالأخص وأنت في عجلة من أمرك , شركتنا يمكنها أن تقدم لك الكثير من الخدمات مثل شركات أفراح مصور أعراس ,يمكنك الاعتماد فى جميع مناسباتك نحن دائما متاحين على مدار 24 ساعة.


خدمة شاي وقهوه الجهراء

شركات افراح بالكويت

مصور اعراس فى الكويت

ضيافة الكويت

خدمة ايقاف السيارات فى الكويت

خدمة شاي وقهوه فى الكويت

تأجير كراسي للعزاء الكويت

تأجير طاولات مضيئه بالكويت

online assignment writing help said...

The experts at Assignment Work Help is the platform where a pool of qualified experts helps the students through their academic writing service for different subjects. There are many reasons which may help you in deciding to choose Assignment Work Help for services such as assignment writing services online for your academics. Here, you get a package full of the featured services with quality at the reasonable low rate. We well understand the situation of students to balance the extra curricular activities, their hard work towards their vision and dreams, the expectation of higher and the best grades while staying calm overall. The experts are not just the writers for their subjects rather they are the known industry consultants in their respective fields. Moreover, they are the pillars of Assignment Work help who put their efforts to provide the solution in an writing service domain.
online assignment writing help
assignment help australia
assignment solution australia
homework help australia
online assignment help
best assignment help
assignment work help usa
assignment writing services in USA

James Wick said...

Hire assignment helpers to Do My Assignment and boost your marks, especially for American university. Take the assistance of experts’ in the US and pay someone to do assignment for no stress and tensions.
Do My Assignment Help
Pay Someone to do Assignment

Suman Sharma said...

Thank you for sharing such informative info, hope you keep sharing, i personally recommend visiting entertainment company

get assignment help online said...

How many times have you ever written ‘online coursework help.’ on Google to seek out the reliable writing services in US? you get the Assignment Help then you have contact our expert team. The support team at GetAssignmentHelpOnline is online 24*7. you'll get in touch with them over the phone or through chat for fast response. you'll also send us an email stating your queries. they're going to go back to to you within a matter of minutes.Visit:
online coursework help
online coursework writing
coursework assignment help
online coursework service
coursework help online
coursework writing service

lee brown said...

My Assignment Help is a one-stop solution for all your assignment help needs. We offer perfect solution to complex computer science academic tasks related to programming, database, IT and computer network as well as other subjects like management, statistics, law, nursing and many more. Our services are available in any subject aiming to offer unique assignment solution leading to better results every time. You can get a clear idea about the quality of our work through a wide range of free samples available on our website.

harryparker0123 said...

QuickBooks is the most efficient, and organized accounting software, which is mainly used by all types of businesses. This tool is very useful from the small and largest businesses and companies for maintaining the records of accounting tasks. I also want to use it for keeping the records of income, expenses, tax, and business profit. I want to Download QuickBooks Free for the maintenance of the accounting tasks in the proper ways. I don’t have much experience to download this free version of QuickBooks. Can anyone suggest the easy tips to download QuickBooks free version?

PNJ Sharptech said...

PNJ Sharptech offers the best Custom Website designing services in India along with digital marketing services at affordable prices. We expect to think again about your character with the target that you increase extreme mileage from the online commercial center. Lead your Business Forward with our Web design Services. For More Query Contact Us +918527749441.

Also Read: Google My Business – For Boosting Your Online Presence

James Martin said...

Assignment Help works best when you don’t have enough time to frame your academic papers. If you are studying in Jordan and need assistance for your assignments, place your order for assignment writing help.

HP Number said...

You can choose to update drivers, disconnect external hardware, run the driver verifier, and change the power settings. Moreover, you can also run a System File checker, and in the end, if anything doesn’t work just reinstall the Windows 10 operating system. By this, you can fix the driver state power failure in Windows OS.

rickysam said...

AssignmentHelpShop.com is the most believed Online Assignment Help task composing administration brand among understudies. We remain on our responsibility and never double-cross our clients. Our master task scholars help you with all subjects. In the event that you need to pay somebody to do task, at that point we are glad to help you in this issue. We will give you a top notch task at sensible costs.
Assignment Help Online
Best Assignment Help
Assignment Helper

Jenifer said...

assignment help melbourne- In these days the assignment is necessary to higher grade studies. Australiaassignmenthelp.com is the best platform to write your assignment unique and easy languages. Assignment writers Australia service provider to best writers for unique assignments