On the native client example page there are two examples that graphics. Pi Generator and Conway's Life
Both of them use all of my cpu (well, one core which is 50%). With Conway's Life the cpu is split between nacl64 and chrome.
Why is it so slow?
I am using chrome 12.0.7
They are supposed to eat up all your cpu. They are benchmarks.
I think it's pretty hard to get to work such examples with such performance if they were written in JS. These examples are very CPU intensive, and they are made to showcase what you can do with it. Performance is really close to native. It is really amazing.
These examples are ports of famous open source projects. You can download original project and compare performance.
Related
Not sure if this is the right place to ask this kind of questions because it is also a bit personal favor but what are your experiences with Xamarin UITest and/or Appium. Until now I only had experience with Appium but for our new project we maybe want to use Xamarin UITest.
Wrong answer, with Xamari UI Test framewor you can automate Progressive Mobile Apps, Hybrid apps a Native Apps, on Android and IOS
Some samples here:
[https://www.zuehlke.com/blog/en/mobile-ui-testing/][1]
We have a React Native app that we are currently testing with Xamarin UI Test, and I've spent quite a while comparing these test frameworks. It looks like our team is going to switch to Appium now. Here is what I like about Appium:
Much better documentation, more resources online
More features (which allows you to automate more stuff)
Runs slightly faster on Android (30% faster maybe), not seeing almost any difference with iOS
Bigger, more active community, less chance of framework becoming deprecated
Based on our experience it's more reliable. With Xamarin we kept getting "device port 27753 in use" or smth like that which we couldn't resolve.
More "device farm" options to run tests on. This is very important for us. With Xamarin the only options I've found are BitBar (flakey, adds about 5 minutes overhead to test runs) and Xamarin Test Cloud (expensive). With Appium there are more options (SauceLabs seems to be working great, we are only starting to use it though)
Allows you to choose from a lot of programming languages (our team is most comfortable with TypeScript)
Client-server architecture which allows test code to run on-premises (might not be a benefit to many teams, but it is to us), so the test code is able to access our internal APIs thanks to this
Firstly, SO is usually not the right place for such questions as such questions usually get closed as off-topic and primarily opinion based. Luckily, xamarin.uitest is a very unpopular tag, hence, your question survived :)
For what Xamarin.UITest does, its actually not bad. The biggest issue to consider is that Xamarin.UITest requires your app to be written using Xamarin.Forms and for me, personally, this is the biggest drawback.
Other issues, that I've encountered:
Scrolling is terribly slow
Limited API (Only basic UI properties can be evaluated, see here)
Minimal differences betqeen Android and iOS which can become really annoying, depending on your use case
Other than that, Xamarin.UITest is a pretty solid UI-testframework and if your app is written using Xamarin.Forms, I would recommend you to use Xamarin.UITest.
I am running R Studio 64bit on a Windows10 laptop with a Nvidia GPU in it, however, when I am running code, specifically Rshiny apps, they take a long time. This laptop has a GPU but my task manager shows that the GPU is not being utilized. Would the GPU make my program run faster? I do not know much about hardware so forgive my ignorance regarding this.
In answer to your question getting a new GPU would have no impact on the speed of your code.
By default most R code is single threaded meaning that it will only use 1 CPU core. There are various ways to do parallel processing (using more than 1 core) in R. And there are also packages that can make use of GPUs. However it sounds like you are not using either of these.
There are various different ways that you could code your application that would make it more efficient. However how you would go about this would be specific to your code. I would suggest you ask a different question regarding.
Also Hadley's excellent book, Advance R, has techniques for profiling and benchmarking your code to increase performance: http://adv-r.had.co.nz/Profiling.html
So I'm new to node.js, javascript frameworks, and meteor.com. I'm trying to learn how to build social networks, and I'm naive/struggling to understand why Meteor.js (meteor.com) wouldn't be able to do all the great things you see now that twitter, facebook, instagram are doing?
There's the comet technology between client/server, authentication configs, asynchronous coding for scaling and performance, and built on top of node.js.
I'm trying to learn more about long polling, comet, gridFS or how files are stored, and in general things like replication sets, and sharding to help with performance (esp since Redhat has this openshift platform that we can build our own private clouds with).
I have some computer science background, but it seems like magic, so what am I missing? If you all could think of a few buzz words that make a social network tick that Meteor.js doesn't support, what would it be?
I hear things about parallel and concurrency (webworkers fixes that in part, no?), websockets, that high level languages like python or java are better off supporting. There's only one to learn my answers, and thats by doing, but thought someone could sway me one way or the other via this thread. Thanks!
This question encompasses a really broad idea and just focusing on using meteor alone would solve this issue. Here are a few points to consider:
I don't think this framework would be a good starting point to learn long-polling, gridFS, etc etc. Meteor aims to be a framework that tends to be more of an ecosystem of packages e.g. you can certainly roll your own aformentioned strategies -- however for dynamic updates, Meteor uses its own Data Delivery Protocol (DDP) supported/implemented by (surprise) a good bunch of core packages such as Spark.
Parallel processing and concurrency can be better off done using other languages, but why not with? Since Meteor is largely based on node.js, and node.js is really good with the aforementioned stuff plus it can play very well with other languages so you could integrate smoothly. Meteor doesn't really require you purely rely on it, as other languages would say the same thing. It's all in the general engineering / planning for your project. There are already lots of really good stuff out there that rely on Meteor, join in! don't be afraid. It all boils down to planning (and the courage/perseverance to pull it off, of course).
Right now, we cannot tell if Meteor would be incapable of the usual great stuff by gigantic websites. Sure, we can do live updates, (its own kind of) publish/subscribe patterns, and powerful stuff to boost development (look at the seven core concepts of meteor to best understand this). It is not impossible to replicate what is already out there, really. We can only say it with uncertainty at the moment mainly because.. (see next point)
The framework is so young! it's still at 0.6.x at the time of writing. Please take time to look at the Meteor Roadmap to see how things are going in terms of broader support for persistence/databases, performance considerations, and the official DDP specification.
I hope I have answered your enquiry (and more, I hope). I'm really excited for meteor myself as it could easily be the next big thing. We have a couple of (for-)production projects using Meteor as well, so you're getting direct insight from a person who has done quite a bit of hacking (and tons of research and first-hand experience) in Meteor. Not that i'm saying i'm an expert or so, it's just so much fun to work with Meteor and i'm totally not kidding you.
Hope this helps!
P.S.: Fair warning though, resources and documentation is really sparse at this point. I try to contribute to the community as much as I can about it (one of my starting points is here, on SO).
Until recently I'd considered myself to be a pretty good web programmer (coming up for 10yrs commercial experience on a variety of e-commerce, static and enterprise applications). I'm self taught and have always used the Microsoft product stack (ASP, ASP.NET)...
My applications are always functional, relatively bug free, but have never been lightening quick. As a frequent web user I always found this to be the norm... how fast are the websites from the big tech players (eBay, Facebook, Microsoft, IBM, Dell, Telerik etc etc) - in truth none are particularly fast. I always attributed this to "the way things are with web apps"...
...then I cam across a product called Jira from atlasian and this has stopped me in my tracks...
This application is fast, and I mean blindingly fast.. too fast to time the switches between pages, fully live content, lots of images and data and cross references etc etc...
I run this on an intranet, with a large application DB, and this is running on a very normal server (single processor, SATA HDD, 8GB RAM).
Am I missing something?? Are my programming techniques that bad?? I am wondering if this speed gain is down to it being written in Java and running on Tomcat.
Does anyone have any benchmarks to compare JSP / ASP or Tomcat / IIS???
Thanks,
Mark
NOTE: this isn't a blatant plug for Jira. I don't work for them or have any affiliation to them... but I would like to be able to write applications like them :)
YMMV. But one of the longest-lived Things That Aren't True Anymore is the assertion that "Java Is Slow". Excepting floating-point (where most Java implementations aren't at liberty to use the floating-point hardware), Java is generally as fast or faster than compiled code. Some of the best and brightest have spent years of effort ensuring this, including such things as dynamic recompilation/re-optimization of code based on run-time metrics - something that statically-compiled languages like C or assembler cannot boast.
ASP is sort of the opposite extreme, since the original ASP had to recompile each page request each and every time it was made. ASPX addressed this by allowing retention of the compiled page code. That got rid of a lot of useless overhead.
A more compelling reason to prefer Java over ASPanything/IIS is freedom. A Java/Tomcat webapp will run under almost any OS on almost any hardware. IIS runs on Windows. Period. And for the most part, that also means Intel. Not Sparc, Not zSeries. Maybe you don't care. But then again, maybe next week IBM will offer your employer a can't-refuse deal on a mainframe.
I don't have benchmarks, and there are a lot of things that can make one platform preferable. But I permanently gave up on the "Java is slow" idea when I encountered the Poseidon UML tool with its cool real-time graphics UI and the FreeMind mindmapper tool. A small hit to startup the JVM, but after that, you'd never know what language you were working under.
The great debate. Java vs. .Net.
When .Net first came out there was an application written called "The Pet Shop." Which was a .Net port of Sun's J2EE reference application, "The Pet Store". It was announced that Microsoft's implementation was "faster."
As with anything, especially anything to do with marketing, you have to dig deeper to find the truth.
Any technology can be fast with enough hardware and the correct design.
In my experience there are two factors to speed: What type of hardware is used and how you architect your application (this includes database tuning).
Caching at various levels (response, db, etc.) makes a huge different in responsiveness of a web application. There is also a lot of things that are done to reduce time consuming operations like db connection pooling, sql statement caching, etc. As much as I'd like to say Java is better :-), I think in this case the performance is due to the way Jira was written and the fact that it's being run internally (probably with few users as compared to eBay, Facebook, Microsoft). This site, Stackoverflow, uses ASP.NET MVC and IIS and is very responsive and my guess (since code is not open sourced, yet) is that they use many of the same techniques you would find in Jira or any other web application built to scale.
I think that it is not typically the frameworks and languages used that make an application slow. In my experience, some frameworks like JSF or .NET server side controls give developers alot of freedom to make too many database calls and look things up too often, but that's definitely not the fault of the framework used.
Keep your application as light as possible and focus on keeping the data sent to the client as small as possible, and you will have a fast application. It's usually faster to develop fast applications too.
The Jira folks have written a best in class application (and charge for it) - nice work crocodile dundees.
I also suggest to consider also two aspects:
the maintenance activities: logging and deployment. In my opinion under a unix like server is more easier to log, deploy, and maintain new release than doing the same on a Windows server.
if the project require to use some open source application (i.e. Alfresco repository) Java is better solutions
People's opinion is mostly biased. Most people have never really tried the other while claiming the other is slower. I wouldn't trust any answer: it's mere opinion. It's boring to always read the same 4 cents again and again.
I'm working on a project that currently has zero users but we would like to scale up to potentially hundreds. Currently we are running on a MySQL database with AMFPHP interacting with Flex. We used Flex because of its robust graphic features (important to this project) and because the initial developer (not me) already knew ActionScript. We are currently using AIR but might switch to web-based Flash at some point.
My questions are:
Is Flex a good tool for a project like this?
What are the main limitations of Flex that we might encounter?
What are other development platforms we might want to consider?
Thanks.
- Dave
Short answer, Yes. There are already many prime-time Apps using Flex as their UI development platform. If you go to the Adobe site they showcase quite a few.
Speaking personally, I chose Flex for two reasons, first was that, although you probably can do much of what Flex does in HTML or with an appropriate toolkit, Flex is designed for attractive and compelling user experience and has available all of Flash. Plus the development environment and available widgets make it easy and fun to program. I don't want to spark a religious war about HTML vs. Flex, so I'll leave that there - it works for me and my application and customers.
Second, and more important, was that it balances the processing load more towards the client which means my server architecture can be optimised just for serving the content and persisting the data. Most of my business logic has migrated across to the client. Having spent many years in classical architectures I think this is a huge step forward, but I can already her a chorus of disagreement about that too.
My word of caution about Flex comes from needing to adopt the right architecture for your client code. It is pretty easy to create a huge and badly performing app with Flex if you get that wrong. Make everything event driven and apparently asynchronous and you should be OK ('apparently' because the Flash player is single threaded). And that is downside 1, the single threaded Flash player sometimes causes issues.
Downside 2 is perhaps more serious and that is locked down desktops in corporate environments. Quite often your target audience won't have administrative rights to their computer and will have either the wrong flash player or none at all. This is particularly true in public sector organisations and the military, so if you are heading there I would test carefully the presence of Flash amongst your users.
Other than that I heartily recommend Flex. It's also a great thing to have on your CV!
HTH
Flex has no inherent scalability problems, however if you have a graphic intensive application, proper serving of these resources might be a problem, but that has little to do with Flex.
The only note-worthy and likely platform you won't be able to run on is the iPhone (no flash) and some older non-flash mobile devices (although most support Flash-lite nowadays)
As for alternatives, if you are Graphics heavy, and don't mind the iPhone, then Flex is good if not best cross platform solution besides using pure HTML technologies, the trick here is HTML alone can do 99% of what Flex can do, but if your App requires the missing 1% then you're out of Luck, also Flex will reduce crossplatform and most browser compatibility issues. So it might make your work more productive.
Silverlight 2 is an alternative to consider. WPF if you're looking for something with offline support.
Yes, the scale and type of project
fits.
Immaturity of frameworks and libraries you might depend on. Immaturity of IDE's.
Silverlight, JavaFX.
Flex + AIR is probably as good a tool as Visual Basic was; it may be a better tool for having a much more flexible programming language and having free development tools, but keep the limitations in mind....
The main limitation I've seen from working with it is documentation. There seems to be not enough documentation, not good enough documentation, and not enough high-visibility work on it in the community. (This is coming from years in .NET; I've been constantly upset with how little MSDN says about methods but generally able to deal with it by finding the most useful blog posts.)
Other possible development platforms would depend very heavily on the specifics of the project. Web-based platforms bog down in deep, stateful interactions with data sets (even with nice AJAX libraries), whereas maintaining client-side installations of any thick client program (say, Flex + AIR) might be overkill if it's just a few CRUD forms.