[RC5] 64bit Linux client slower than 32bit client?

David Bolt rc5-3 at davjam.org
Sat Oct 25 15:45:34 EDT 2008


Having just noticed the release of the latest clients, I decided it
might be a good idea to benchmark the 64bit clients before starting to
use them on my 64bit systems, rather than continuing to use the 32bit
clients as I am now. However, on the two systems I've performed the
benchmarks, both have shown that the 32bit client when benchmarking the
RC5-72 core is at least 500kkeys faster than the 64bit client on the
same system.

The first system, an AMD Sempron based system running the 64bit version
of openSUSE 10.3 at 1.6GHz, is consistently 500kkeys/s faster with the
32bit client.

The second system tested, an AMD 64 X2 4200+ running the same 64bit
version of openSUSE 10.3 but at 2.2GHz per core, is also consistently
700kkeys/s faster with the 32bit client.

So, my question is does anyone have an idea why there should be this
drop in speed?

Also, as a matter of interest, while doing the benchmarking of the
latest clients, the latest 64bit client on the X2 is shown to be almost
1Mnode/s faster than the latest 32bit client, and a little more than
1Mnode/s faster than the 32bit 504 client I was previously using.

dav2:/usr/lib/dnetc # ls -l dnetc-2.90*
-rwxr-xr-x 1 root root 463952 Sep 26  2005 dnetc-2.9008.490
-rwxr-xr-x 1 root root 983576 Jun  8  2005 dnetc-2.9011.496
-rwxr-xr-x 1 root root 983576 Oct 13  2006 dnetc-2.9011.496.64bit
-rwxr-xr-x 1 root root 512816 Dec 28  2005 dnetc-2.9012.497
-rwxr-xr-x 1 root root 521300 Nov 27  2006 dnetc-2.9013.498
-rwxr-xr-x 1 root root 523348 Feb  8  2008 dnetc-2.9015.504
-rwxr-xr-x 1 root root 531624 Oct 25 19:58 dnetc-2.9016.506.32bit
-rwxr-xr-x 1 root root 972256 Oct 25 19:58 dnetc-2.9016.506.64bit
dav2:/usr/lib/dnetc # ./dnetc-2.9016.506.64bit -benchmark ; ./dnetc-2.9016.506.32bit -benchmark ; ./dnetc-2.9015.504 -benchmark

distributed.net client for Linux Copyright 1997-2008, distributed.net
Please visit http://www.distributed.net/ for up-to-date contest information.
Start the client with '-help' for a list of valid command line options.


dnetc v2.9016-506-CFR-08081716 for Linux (Linux 2.6.22.17-0.1-default).
Please provide the *entire* version descriptor when submitting bug reports.
The distributed.net bug report pages are at http://bugs.distributed.net/

[Oct 25 19:22:48 UTC] Automatic processor type detection found
                      an AMD Athlon 64 X2 Dual Core processor.
[Oct 25 19:22:48 UTC] RC5-72: Running micro-bench to select fastest core...
[Oct 25 19:23:19 UTC] RC5-72: using core #1 (KBE-64 3-pipe).
[Oct 25 19:23:40 UTC] RC5-72: Benchmark for core #1 (KBE-64 3-pipe)
                      0.00:00:17.36 [8,813,006 keys/sec]
[Oct 25 19:24:00 UTC] OGR-P2: Benchmark for core #0 (GARSP 6.0-64)
                      0.00:00:18.12 [29,896,330 nodes/sec]

distributed.net client for Linux Copyright 1997-2008, distributed.net
Please visit http://www.distributed.net/ for up-to-date contest information.
Start the client with '-help' for a list of valid command line options.


dnetc v2.9016-506-CFR-08081716 for Linux (Linux 2.6.22.17-0.1-default).
Please provide the *entire* version descriptor when submitting bug reports.
The distributed.net bug report pages are at http://bugs.distributed.net/

[Oct 25 19:24:00 UTC] Automatic processor type detection found
                      an AMD Athlon 64 X2 Dual Core processor.
[Oct 25 19:24:00 UTC] RC5-72: using core #6 (GO 2-pipe).
[Oct 25 19:24:22 UTC] RC5-72: Benchmark for core #6 (GO 2-pipe)
                      0.00:00:17.57 [9,442,506 keys/sec]
[Oct 25 19:24:22 UTC] OGR-P2: using core #4 (GARSP 6.0-asm-rt1-mmx-amd).
[Oct 25 19:24:40 UTC] OGR-P2: Benchmark for core #4 (GARSP 6.0-asm-rt1-mmx-amd)
                      0.00:00:16.27 [28,904,560 nodes/sec]

distributed.net client for Linux Copyright 1997-2007, distributed.net
Please visit http://www.distributed.net/ for up-to-date contest information.


dnetc v2.9015-504-CFR-07110717 for Linux (Linux 2.6.22.17-0.1-default).
Please provide the *entire* version descriptor when submitting bug reports.
The distributed.net bug report pages are at http://www.distributed.net/bugs/

[Oct 25 19:24:40 UTC] Automatic processor type detection found
                      an AMD K8-11 processor.
[Oct 25 19:24:40 UTC] RC5-72: using core #6 (GO 2-pipe).
[Oct 25 19:25:01 UTC] RC5-72: Benchmark for core #6 (GO 2-pipe)
                      0.00:00:17.56 [9,409,983 keys/sec]
[Oct 25 19:25:01 UTC] OGR-P2: using core #4 (GARSP 6.0-asm-rt1-mmx-amd).
[Oct 25 19:25:20 UTC] OGR-P2: Benchmark for core #4 (GARSP 6.0-asm-rt1-mmx-amd)
                      0.00:00:16.24 [28,813,607 nodes/sec]
dav2:/usr/lib/dnetc #


Regards,
        David Bolt

-- 
Team Acorn: http://www.distributed.net/ RC5-72 @ ~70Mkeys/s
SUSE 10.1 32 |                   | openSUSE 10.3 32b | openSUSE 11.0 32b
             | openSUSE 10.2 64b | openSUSE 10.3 64b | openSUSE 11.0 64b
RISC OS 3.6  | TOS 4.02          | openSUSE 10.3 PPC | RISC OS 3.11


More information about the rc5 mailing list