I am using 32 bit openSUSE OS, and I am using a cross compiler to build 64 bit application( it does not support building 32 apps) as our software will be deployed on a machine which is 64 bit OS. As testing on target is not always possible, is there anyway to run this applications on my 32 bit OS.
Use something like QEMU that can emulate a 64-bit processor.
Short answer: No, there is no way.
Longer answer: If you have a 64-bit CPU it may be possible to run a 64-bit virtual machine, even though your host OS is 32-bit. I'm not 100% sure about that, though, you'd have to try it.
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Of course my target Linux is running on a 32 bit MCU. So are there any restrictions if my host environment is running on a 64 bit system?
Or should I just take the 32bit host version and not care about the 64 bit version. I mean the only thing I am doing is build applications for my embedded device. Or are there any speed advantages on a 64 bit host system regarding GCC compilation, QT programming , etc...
What is your personal point of view on this?
Technically, no real change happens.
But, from my personal experience, you may encounter problems if you have to copy the development environment to another computer and you don't want to do a complete setup (for example: a broken host, or having to do maintenance after several months to the code, possibly not done by the same author of the original code and/or nobody remembers how they did the setup when the development was started). Using a 64 bits limits this "portability". For now there are multiarch distributions like Debian, you can face even more problems if you need to quickly set up another machine.
This is why I ended with using virtual machines running 32 bits GNU/Linux: if you need to quickly setup a new computer, just copy a bunch of files, make sure you have virtualbox or vmware installed on the new pc and you're almost done.
I remember hearing that for performance a development machine should be 32 bit, while servers should be 64 bit. I think it was Richard Campell on Dot Net Rocks! that mentioned this.
Why would 32-bit be faster than the 64-bit for a development box and vice versa for servers?
One major reason is the fact that 32-bit OSs can't address 4GB of RAM. 4-8GB can be crucial in a lot of development environments where virtual machines are involved, or even heavy lifting in general. This is why I always stick with 64-bit where possible, and all modern CPUs support it.
It depends in part on your tools - for example, Visual Studio is still a 32 bit app (but usable from x64 - just no huge gain).
However, if you are using your main OS to host VMs, then you can probably benefit from a ton of memory for your various virtuals - and then you can choose 32-bit and 64-bit VMs to suit your needs (it is harder to have a 64-bit guest VM in a 32-bit host).
Personally, I'm still on 32-bit for development. For most of what I do, it is fine.
I run 64-bit 2008 Server and see not performance issues whatsoever. In fact, it's much better than 32-bit XP. It performs generally faster. In a funny way, file operations are quicker on my laptop 5400rpm drive running 64-bit 2008 Server than on a office PC with a 7200rpm drive running 32-bit XP.
I can think of only one thing why you would want to run a 32-bit OS (XP being the latest): you get there IE6 to debug your sites.
The other thing is that a 32-bit OS is incapable of addressing RAM capacity over ~3,4 Gb. If your PC has 4+ Gb of RAM you only loose with a 32-bit OS. Recollecting that even consumer laptops are sold these days with 4, 6 and 8 Gb of RAM, one can safely say goodbye to a 32-bit OS.
If you are talking about non-Windows OS then my experience may not apply.
Having a lot of memory changes the way you work, sometimes dramatically. I run 8 virtual screens with 4 different development environments (1 trunk, 2 branches and a fourth environment for external projects). Just with 12GB mem and a 30" screen.
I don't think that 32 bit machines are faster then 64 machines for developers. It is true that your development environment on a 64 bit OS is running in an emulated 32 bit environment and that creates a slight overhead. On the other hand you will find that the 64 bit OS is slightly faster as the internal data paths are 64 bit enabling the OS to move twice as much data in a single operation. This makes the 64 bit OS slightly faster than a 32 bit OS. The downside of a 64 bit OS is that pointers are twice as big.
What really matters is that 64 bit OS'es are very stable, have access to much more physical memory, and can run both 64 bit and 32 bit applications and virtual machines without sacrificing performance. The 32 bit OS belongs to the past.
I have a 64-bit Ubuntu installed in my laptop. I use it for development and I have no performance issues at all. I have the feeling that computer resources are better used this way.
The only reason I can think of to choose 32-bit OS is that you know that what you develop will work on 32-bit and 64-bit machines. But VS let you choose your target machines...
His point was if you develop for 32bit you will have less than 4GB of ram to work with. And on a 64bit server you may have much more than 4GB of RAM. Basically tricking you into being more frugal with your memory requirements. It had more to do with memory usage than raw number crunching on the CPU.
Although I can't quantify it in numbers, I have noticed the same thing as 'new in town'. I used to run XP x86, and later vista x86 on my notebook. After I upgraded to Vista X64 it is a lot snappier. Don't know if it is a driver issue, the fact that I run SQL Server x64 etc, that it can use twice the amount of cpu registers, optimizations in 'internal' stuff in windows or what, but I can notice the difference...
I'd think the obvious suggestion would be to use whatever OS your code is going to be deployed on. If your development environment is as close as possible to the deployment environment, there's less chance of bugs showing up only in the deployment environment.
I am pricing a new software development machine and looking at the dell precision series.
When I get to this screen:
http://www.dell.com/content/topics/reftopic.aspx/pub/products/precn_kat?c=us&cs=555&l=en&s=biz&~section=T7400
The first choice is: Buy a Precision WorkStation T7400 32bit Now!
and the second choice is: Buy a Precision WorkStation T7400 64bit Now!
am I really at that point just deciding which software I want installed? or is there actually a different chipset depending on the choice.
I don't want to limit my options down the road by picking the wrong one - I can always upgrade the software - but I don't want to have to replace hardware.
BTW: This will be for SD of a Microsoft stack, asp.net, vs 2008, sql server etc and I would like to start using virtualization (probably from MS) with this machine purchase.
Both options give you the same choice of processors, they are all 64-bit capable. It's just a matter of whether a 32-bit or 64-bit version of the OS is preinstalled on it.
I would go with the 64-bit option simply because, in my experience, you can easily run both 32-bit and 64-bit VMs on a 64-bit platform, but are limited to 32-bit VMs on a 32-bit platform.
64-Bit, but just not XP64 (Which Dell offers as a downgrade). Driver situation is quite awful, and there are some incompatibilities in Software. If you need/want to stick to XP, go 32-Bit, if you want to use Vista or Windows Server 2008, 64-Bit is fine.
The only difference is the operating system anyway, so you can freely switch between installing 32 or 64 Bit Windows, you may just need to buy another License.
100% 64bit. RAM is cheap and you'll eventually want to use more than 4GB of it, especially if you've going to be running virtual machines.
64bit all the way. Vista64 is mature at this point, I haven't run into any issues. If you need 32bit for any older peripherals you might have, install XP32 as a VM.
As far as I know you can't really buy a 32-bit PC nowadays. I think the OS is the only different between the 32bit and 64bit version.
For .NET development it doesn't matter whether you're using a 64-bit OS or not. However 64-bit SQL Server maybe running faster.
And you'll also need more than 4GB RAM (especially if you run virtual machines), so I don't really see any reason to choose a 32-bit OS over a 64-bit one.
I would go for 64bit with 64bit Operating System. Only problem i encountered so far is that 32bit apps cannot access 64-dlls -> For example the context menu of TotalCommander won't show 64bit apps (e.g subversion) which might be inconvenient for development.
It can be difficult to get 64bit drivers for exotic or very new hardware, so if that's a concern for you, you might want to stick to the 32bit OS.
This is only a half-way programming question. First of all I have a PCI-Express card and 32/64 bit drivers. The target operating system has to be a Windows 64 bit system. I read that under Vista64 all drivers have to be certified 64 bit drivers. Is this a general restriction under 64 bit operating systems and does this also apply to "XP 64" or any Linux system?
So for simplicity let's say I use a 64 bit driver for my PCIe card under Vista64 and have a bunch of 64 bit DLLs to use the cards functionality. On the other side there's a large, legacy 32 bit exe program which needs to use the PCIe device. Converting the program to 64 bit would be a really huge effort.
So what can be done to bring that 32 bit program and the 64 bit driver together? I read that mixing 32/64 bit binaries and DLLs is not possible at all but this is hard to believe for me. I'm sure you can print out a document under Vista64 from within a 32 bit app and Windows will somehow wrap this around to a 64 bit printer driver.
64-bit certification is only required under Vista; there is no certifying authority for non-Windows platforms, and I don't believe that XP or Windows Server checks for certification (not sure though, and it may depend on which service pack you're on).
If you're using the driver via the Windows API, then there shouldn't be any problem; Windows will do the 32<->64-bit translations in the kernel. If you're trying to load the driver inside your own process, that probably won't be possible. As Dirk says you'll have to run it inside its own process and communicate through a COM server. I'm not sure what hoops you'll have to jump through if you have to run your driver in a higher-privilege execution level and want to make calls to it from user mode.
Hopefully your 64-bit DLLs offer a 32-bit API, or Windows offers a standard driver interface (if it's a common I/O device like a display or network card).
Does your 32-bit application directly call the driver? (I'm guessing a simulator for the driver!)
The only way to communicate between 32-bit and 64-bit dlls is to write a COM server that manages the communication (read: wrap EITHER the applications calls OR the 64-bit driver responses) in between.
One thing that came back to bite me: When I first wrote this COM server (yes, I too had to bear many sleepless nights before I came to know of this trick) I only built the 32-bit version of the (auto-generated) proxy/stub dll. Another bout of sleepless nights ensued before I came to know of the solution: Build the proxy/stub dll for both 32-bit and 64-bit. The 32-bit side deals with the 32-bit side (in your case the application) and the 64-bit with the 64-bit side (the driver). COM manages how the differnt versions of the proxy/stub talk to each other. And oh, do get the server registered on your system. Easy, right?
I think the whole point of a driver is to abstract away the actually workings of the hardware and present a common interface to the software. In this case, the PCIe driver needs to be 64-bit so that it can act as a go-between for Windows and the hardware, but I would think that a 32-bit application could then access the device without any troubles at all.
What's meant by that incompatibility you read about is that 32 and 64-bit assemblies can't be part of the same application - an application has to target either one or the other, though 32-bit application will generally run fine on Windows x64 using WoW64, which just acts as a translator.
Are you currently experiencing problems, or are you just asking hypothetically?
I have just installed a build server with a 64 bit windows server 2008 for continuous integration.
The reason I choose a 64 bit server was to have more than ~3Gb of RAM. I had hopes that this machine would provide blazing fast builds.
Unfortunately, the result are lacking greatly to say the least. My desktop provides faster builds than this server equipped with a Xeon quad core, 15k RPM SAS and 8 Gigs of RAM.
We use Visual C++ 2005 to compile our 32 bit application with Cygwin.
Could the WOW64 emulator be the bottleneck that is slowing down the build process?
Any pointers, comments would be greatly appreciated.
Regards,
We use Visual C++ 2005 to compile our
32 bit application with Cygwin.
I think that's the problem. I like Cygwin a lot, but it is really slow when it comes to file I/O. It helps a bit to deactivate the NTFS filesystem feature to keep track of the last file-access.
To get a better speed boost port your build-script / makefile to use the native command shell if pssible and only call cygwin-tools if there is really no replacement available.
If you use the gcc compiler try the mingw version. That one is a lot faster.
WOW64 is not an emulator on x64. The processor natively executes 32-bit x86 code. At the bottom of the user-mode stack, under kernel32 et al, are DLLs which map system calls to the 64-bit call interface.
See WOW64 Implementation Details.