climateprediction.net home page
Posts by ebahapo

Posts by ebahapo

1) Questions and Answers : Wish list : Support for BOINC - x64 version (Message 41930)
Posted 7 Apr 2011 by ebahapo
Post:
MT can be done at several levels. At a model level, as you said, or inside each model. For instance, wherever a large array is operated on, it can be done with multiple threads, when the time to execute this operation takes approximately T/N. If OpenMP is used, this can be done quite easily, with most of the work being done by the compiler.
2) Questions and Answers : Wish list : Support for BOINC - x64 version (Message 41928)
Posted 7 Apr 2011 by ebahapo
Post:
Actually, Windows 7 is the last version of Windows to be available as a 32-bit OS. But, in all fairness, Windows 8 will continue to run 32-bit programs like CPDN just like Windows 7 does. And that without the library issues that some 64-bit Linux systems pose.

However, such a long-running application like CPDN can benefit greatly from some performance improvements. The 64-bit calling interface is much more efficient and floating-point operations are more efficient too, placing intermediate values in registers rather than on a stack as in IA32. The difficulty is that floating-point operations are performed on only 64 bits in a 64-bit application, whereas they are performed on 80 bits in a 32-bit application. This means that the results might be slightly different. Other projects, especially those that run on RISC systems, like SETI and Einstein, have some latitude when validating the results of different platforms.

But then there's the benefit of MT, which could decimate the run-time of CPDN. And this can be done even if the result differences above are a major hurdle in validating the correctness of a 64-bit port. An MT 32-bit application would still be several times faster than the current CPDN application.

If I can get the source code under an NDA, I'd be glad to be of any help.
3) Questions and Answers : Wish list : Support for BOINC - x64 version (Message 41924)
Posted 7 Apr 2011 by ebahapo
Post:
I'm a seasoned software engineer who contributed to the definition of the x86-64 ISA during my tenure at AMD. I ported the classic SETI application to that architecture and converted many scientific applications to multiple threads. I'd be glad to work on CPDN applications and port them to 64 bits and MT.
4) Questions and Answers : Wish list : AMD64 (Message 31760)
Posted 17 Dec 2007 by ebahapo
Post:
Even though there\'s an official AMD64 client for Linux, it refers to too many dynamic libraries and requires a fairly recent Linux setup to run on.

So, one more time, I\'m making available the AMD64 Linux client here. It refers to a minimal set of standard dynamic libraries whose version requirements should be satisfied by Linux systems up to 2 or 3 years old, however it was built with a fairly recent version of GCC, 4.1.2.

The drill\'s still the same:


The official AMD64 Windows client can be found here.

For more information, see the BoincStats Forum.

HTH

5) Questions and Answers : Windows : Message from server - platform not found (Message 31185)
Posted 30 Oct 2007 by ebahapo
Post:
Your memory is slightly off here. There are only two projects so far that GAIN any significant processing speed from running a 64bit app, ABC and APS. There are a few more that have native 64bit apps but they do not make a difference.

This is not true. 64-bit applications typically experience an improvement of 10% due to the greater number of registers available, as I explained here.

You could say though that ABC, APS and SHA-1 gain SIGNIFICANT speed from 64 bits.

HTH
6) Questions and Answers : Windows : Message from server - platform not found (Message 31184)
Posted 30 Oct 2007 by ebahapo
Post:
If you are content with ABC\'s 64-bit client (assuming it is 64-bit, most of the Projects which recognize 64-bit boinc have 32-bit clients -- but, if memory serves, two of about 50 actually have them), then have at it. Your choice.

That\'s not correct. You\'re entitled to your own opinions, but not to your own facts. See this thread for the facts.

There are 14 projects that provide native 64-bit applications. The overwhelming majority of projects support 64-bit clients with just a handful of projects that haven\'t upgraded the server software, including CPDN.

HTH
7) Questions and Answers : Wish list : Support for BOINC - x64 version (Message 30919)
Posted 9 Oct 2007 by ebahapo
Post:
However I notice from the list you kindly posted on the other thread that he is running SIMAP, which *does* have a native 64-bit app. I don\'t know what the relative performance of that SIMAP app is, compared to the 32-bit version.

As you can see here, it\'s about 7% faster. With vectorization enabled (which can be assumed in 64 bits), it improves by additional 8%. Therefore, a potential improvement of 15%. Even pessimistically, as CPDN WUs take weeks to complete, there might be a shortening of the run-time by up to 3 days.
The main advantage of 64-bit code is that it can easily handle process-memory space of 2GB and above, it is not necessarily quicker than 32-bit code (APS is an exception, 50% faster than the 32-bit version). At present there are no Boinc apps using more than 2GB of memory, although at one point Carl was working on a 4.7GB climate model.

No. The main advantage of AMD64 over x86 is that it provides more registers and uses SSE by default, allowing for greater performance due to reduced number of instructions and fewer memory loads and stores. Typically, applications display an increased performance by 10% when ported to AMD64 from x86.

This rule-of-thumb is confirmed by SETI, SIMAP, ABC, APS, Chess960 and other BOINC projects. Rather, no performance improvement is the exception, with performance degradation being even more exceptional.

But given the that effort behind a port may be substantial, for the moment upgrading the BOINC server software would be a step in the right direction.

HTH
8) Questions and Answers : Wish list : Support for BOINC - x64 version (Message 30905)
Posted 8 Oct 2007 by ebahapo
Post:

As far as I know all the projects you subscribe to use 32-bit code, so there\'d be no problem in running the 32-bit client on your system?

This kind of reply is not helpful. This is a volunteer project, yet you\'re suggesting the volunteer to change his preferences if he wants to crunch for CPDN. Shouldn\'t CPDN cater to the volunteers instead, if for anything out of gratitude for their contribution?

Come on, how hard is it to create a copy of the 32-bit applications with names including the 64-bit platforms and adding support for them to the server? This has already been done in the beta project...

Thanks.
9) Questions and Answers : Windows : Message from server - platform not found (Message 30882)
Posted 8 Oct 2007 by ebahapo
Post:
At the risk of repeating myself, see this. As you can see 14 BOINC projects send native 64-bit applications for at least one OS. Many of them with less funding than CPDN, but evidently with more enthusiasm and gratitude towards its volunteers.

HTH
10) Message boards : Number crunching : 64 Bit Version: when will it arrive? (Message 30881)
Posted 8 Oct 2007 by ebahapo
Post:
At the moment, 14 BOINC projects povide native 64-bit applications for at least one OS, as you can see here. Almost all of the other BOINC projects are courteous enough to send at least 32-bit applications to 64-bit clients instead of shunning them.

HTH
11) Questions and Answers : Windows : Message from server - platform not found (Message 30442)
Posted 8 Sep 2007 by ebahapo
Post:
It would be quite helpful if CPDN would just upgrade the server software in order to support the official x64 Windows client.

The new server software sends the 32-bit application to such clients if the project doesn\'t provide 64-bit applications.

Thanks.
12) Questions and Answers : Unix/Linux : platform \"x86_64-pc-linux-gnu\" not found (Message 30441)
Posted 8 Sep 2007 by ebahapo
Post:
It would be nice then if CPDN would upgrade the server software now that the current 64-bit clients can request 32-bit applications if 64-bit ones are not supported.

Thanks.
13) Questions and Answers : Wish list : AMD64 (Message 29968)
Posted 13 Aug 2007 by ebahapo
Post:
Here\'s a development version of the x86-64 Linux client:


The official client for x64 Windows client can be found at boinc_5.10.13_windows_x86_64.exe.

The BOINC client 5.10 can now get 32-bit applications from projects that haven\'t added support for AMD64 (e.g., Lattice, QMC, etc), provided that they run at least the BOINC server 5.0.9. However, such AMD64 clients for Windows may not get applications from some projects that supported AMD64 before due to a platform name change, at least until such projects are updated.

For more information, see the BoincStats Forum.

HTH

14) Questions and Answers : Wish list : AMD64 (Message 27758)
Posted 6 Apr 2007 by ebahapo
Post:
Here\'s the new recommended version for the x86-64 Linux client:


Again, Crunch3r\'s x64 Windows client can be found at boinc_5.8.11_windows_amd64.zip.

For more information, see BoincStats Forum.

HTH

15) Questions and Answers : Wish list : AMD64 (Message 27724)
Posted 4 Apr 2007 by ebahapo
Post:
You may need to ask your self which is more important:
Only run 64 bit science apps, or run whatever climate model is available.

One doesn\'t have to exclude the other. Many projects send the 32-bit application to 64-bit clients, when they can continue to contribute to those projects that don\'t support 64 bits natively. CPDN could follow the same route creating the 64-bit application as an alias to the 32-bit application. Of course, BOINC intends to make this happen automatically in future versions of the back-end (see this), but until then, the accommodation of 64-bit clients must be done manually.

Anyways, those who\'d like to try out running 64-bit BOINC, can download the x86-64 Linux client, version 5.8.15, from boinc_5.8.15_x86_64-pc-linux-gnu.tgz (make sure to read the file \"README.x86_64-pc-linux-gnu\" in it), and Crunch3r\'s x64 client, version 5.8.11, from boinc_5.8.11_windows_amd64.zip.

For more information, see BoincStats Forum.

HTH
16) Questions and Answers : Wish list : AMD64 (Message 24636)
Posted 10 Oct 2006 by ebahapo
Post:
So far, two projects have added support for x86-64: SETI sends the x86 application and SIMAP, a true x86-64 application. Would you consider supporting the platform x86_64-pc-linux-gnu or x86_64-unknown-linux-gnu similarly?

HashClash now supports AMD64 with a 32-bit Linux application and Chess960 with a 64-bit Linux application...

HashClash now supports AMD64 with a 32-bit Windows application too...

Guess what? Leiden Classical now supports AMD64 on Linux with a 32-bit application. ;-)
17) Questions and Answers : Wish list : AMD64 (Message 24448)
Posted 28 Sep 2006 by ebahapo
Post:
FWIW, running two instances of the client, one the 32-bit client, the other, the 64-bit client, on the same 4-core system, but limiting each client to 2 cores, I can compare the relative performance of 32-bit and 64-bit SIMAP\'s HMMER: the 64-bit version is about 7% faster.

By enabling vectorization (supported by default on AMD64), the SIMAP developers observed other 8% improvement.

That\'s a potential performance improvement of 15% when porting the project application to AMD64.
18) Questions and Answers : Wish list : AMD64 (Message 24441)
Posted 28 Sep 2006 by ebahapo
Post:
So far, two projects have added support for x86-64: SETI sends the x86 application and SIMAP, a true x86-64 application. Would you consider supporting the platform x86_64-pc-linux-gnu or x86_64-unknown-linux-gnu similarly?

HashClash now supports AMD64 with a 32-bit Linux application and Chess960 with a 64-bit Linux application...

HashClash now supports AMD64 with a 32-bit Windows application too...
19) Questions and Answers : Wish list : AMD64 (Message 24365)
Posted 20 Sep 2006 by ebahapo
Post:
So far, two projects have added support for x86-64: SETI sends the x86 application and SIMAP, a true x86-64 application. Would you consider supporting the platform x86_64-pc-linux-gnu or x86_64-unknown-linux-gnu similarly?

HashClash now supports AMD64 with a 32-bit Linux application and Chess960 with a 64-bit Linux application...
20) Questions and Answers : Wish list : AMD64 (Message 23929)
Posted 14 Aug 2006 by ebahapo
Post:
Then how about sending the x86 application to hosts reporting the AMD64 platform, both Linux and Windows? This way, hosts running the AMD64 client would be able to run the CPDN application as well.

Thanks,


Next 20

©2024 cpdn.org