-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Monday, December 23, 2002, 2:38:57 PM, Ronald wrote: > As an experiment, I've copied my raw data and compilation app to > another system with 1 GB of RAM, a 4 GB swap partition, and SCSI > drives that show about 50 MB/sec buffered read throughput. It will be > interesting to see how fast that finishes. The original system is > an HP desktop box, running with a 1.6 GHz P4. This other system is a > Dell server configuration running a pair of 1 GHz P3 (Coppermine) > processors. (The data compile process is not multi-threaded.) Anyway, > I would guess that if cpu bound, the experiment will take longer, but > if memory/disk/swap bound, the experiment will take less time. The experiment concluded. The dual P3 system with SCSI drives is running RH 8.0 kernel 2.4.18-14smp, versus the P4 system running RH 8.0 kernel 2.4.18-18.8.0. The elapsed time was 11 hours 7 minutes. For the experiment, ran the data compilation under "time -v", and learned that the job got 5% of the cpu time during its run. This says to me that cpu time is not the main factor in performance. There were several million page faults. Since the same executable was used both places, it's not likely to be a compiler problem. (The executable was *not* statically linked.) In summary, using the same hardware (P4) on ext2 filesystems, my job went from less than 7 hours to more than 48 hours. At the same time, the job runs in about 11 hours on a dual P3 with SCSI drives and a bit more RAM. The differences I see that might be accounting for the big performance hit: 1) Kernel Version (memory management / paging, code and algorithms) 2) 8.0 increased memory footprint vs 7.2 (???) leading to more paging Any ideas? Ron. -----BEGIN PGP SIGNATURE----- Version: PGP Personal Privacy 6.5.8 Comment: Until recently, the last PGP with full source disclosure. iQA/AwUBPgiUVG8pw+2/9pUJEQLAEQCghD5AAzrm3eBxIOJHrI7D5HrsMAsAnifa LObQm5/0ABWpT+BbOPzemsBU =8JTB -----END PGP SIGNATURE----- -- Psyche-list mailing list Psyche-list@redhat.com https://listman.redhat.com/mailman/listinfo/psyche-list
