Recent DDT Benchmark Results

ALPHA AXP

Gabriele Giovannini reports an AIPSMark of 58.8 on an Alpha Digital/Compaq XP1000 system running Red Hat Linux (version 6.2) and using the DEC/Compaq Compilers natively under Linux. This DDT run finished in 68 seconds! It also confirms that the best compilers to use under Alpha Linux are indeed the Compaq (DEC) ones. The particulars of the compiler optimization levels and switches used is not available yet, but we hope to have this information folded back into 31DEC00 shortly. One problem to be solved is an apparentl failure of FITLD to build (Gabriele used an OSF1 FITLD binary to load the data instead).

The Compaq Solutions Alliance (CSA) has a service where they grant access for porting, benchmarking, etc. on their top of the line systems. As NRAO is a CSA member, we were recently able to take advantage of this to try one of their latest systems. This was an Alpha DS-20 system with dual processors, both 21264 chips apparently running at 500 MHz (according to the bootup messages). The system had 2 Gigabytes of memory and the ADVFS cache was initially set to 7%, then increased to 20% for the tests. Using a fast RAID system and three separate filesystems (data on raid and one other fast SCSI disk, AIPS infrastructure on the third -- also fast SCSI -- disk), the result was 33.61 AIPSMarks. This translates to running the large DDT in AIPS in 119 seconds; the first time it has happened in under two minutes.

NRAO now has three ALPHA systems in-house at its Charlottesville location. The latest addition is an ALPHA clone from a third party vendor with 64 megabytes of memory running the 21164 chip at 433 MHz. We have successfully installed Linux 2.1.57 on it, and are working on various ways of running AIPS on it. The first attempt was to generate static binaries on another (DEC) ALPHA processor using Digital's FORTRAN compiler under Digital Unix (OSF/1) and run these on the Linux/ALPHA system; this has been done and appears to work. The best AIPSMark to date has been 9.0 when using SCSI disks. Interestingly, using EIDE disks can cut this figure in about half. Unfortunately, a complete set of binaries for such a system will be >500 Megabytes when statically linked. On the positive side, the ballpark price for this system was about US$5k or less than $600 per AIPSMark.

Our workhorse DEC ALPHA system is an ALPHAstation 500/400 (400MHz), with 512 Megabytes memory and about 24 Gbytes of disk space; the most recent AIPSMark from it gave a result of 12.0, matching the result on the 500MHz model (see below). The gain can probably be explained by the superior I/O subsystems: there are two SCSI busses on this system, and the disks were laid out using DEC's Advanced File System (quasi-striped). The binaries were served via NFS (from siamang, our older 266 MHz ALPHA), but the system files (DA00) and data areas were all local.

During the process of upgrading all our Digital ALPHA systems to OSF/1 V4.0 (Digital Unix), our oldest system pongo was re-tested with surprising results. In the various previous trials, it had come in just barely above 2, but with OSF/1 3.2 binaries it managed a respectable 3.0; a retest with V4.0 binaries yielded 2.9 but the difference could well be in the noise. This is an older ALPHA based on the 21064 chipset: a Dec ALPHA 3000 model 300 with 96 Megabytes of memory and about 6 Gigabytes of disk space (again, the data disks were Advanced File Systems, DA00 was local, but binaries were served from siamang).

Results on an ALPHAstation 500/500 (500MHz) with 128 megabytes of memory, 313 megabytes swap, fast/wide SCSI-II disk, Digital Unix 4.0A: 12.0 AIPSMarks(93). It was undetermined which swap allocation mode was in use during these tests; However, given that there was practically no swapping of any sort occuring, this is not really relevant.

NRAO has been fortunate in receiving a loaner system from Digital Equipment Corporation (DEC) of what was called the Alcor system. This is now released as the 2D ALPHAStation 600 5/266 workstation, with 128 MB Mem, 2GB disk, 2MB cache, and ZLXpE1 (2D graphics accelerator). By playing somewhat with the compilation options (and recorded in the latest version of AIPS in the $SYSUNIX/FDEFAULT.SH and $SYSALPHA/LDOPTS.SH files), we have achieved AIPSMark(93) values in the range 8.1 - 8.4. This is without the benefit of routines such as the $QVEX routines used for the Silicon Graphics test below.

The people at Brandeis have a Dec ALPHA 3000 model 600 with 128 Megabytes of memory, 350 Megabytes of swap space and OSF/1 version 1.3. They ran the 15JAN94 version of AIPS on it and the Large DDT gave an AIPSmark(93) of 3.887. The test was carried out in March 1994 and performed by Scott E. Aaron (sea@vlbi.astro.brandeis.edu) and JingPing Ge (jpg@vlbi.astro.brandeis.edu). Many thanks to both of them for sending me the results.

Patrick P. Murphy