Hi Bruce, Do you have any idea what the performance impact from enabling scrubbing is on your systems? did you do any before/after benchmarking?
Thanks, -stephen Bruce Allen wrote: > On Sun, 3 Sep 2006, Mark Hahn wrote: > >>> ECC Features >>> ECC Enabled >>> ECC Scrub Redirection Enabled >>> Dram ECC Scrub CTL Disabled >>> Chip-Kill Disabled >>> DCACHE ECC Scrub CTL Disabled >>> L2 ECC Scrub CTL Disabled > > You can find our systems BIOS/ECC/Scrub settings here: > http://www.lsc-group.phys.uwm.edu/beowulf/nemo/construction/BIOS/bios_settings.txt > > Our systems are Supermicro H8SSL-i motherboards, with a > Serverworks/Broadcom HT1000 chipset and a single Opteron 175 (dual core, > 2.2 GHz). > > The ECC part is: > DRAM ECC Enable = Enabled > MCA DRAM ECC Logging = Enabled > DRAM Scrub Redirect = Enabled > DRAM BG Scrub = 2.62ms > L2 Cache BG Scrub = 84.00ms > Data Cache BG Scrub = 84.00ms > > Scrubbing is done one cache line (64) bytes at a time. Thus with 2GB of > memory and DRAM background scrub interval of 2.62ms we will scrub the > entire memory in approximately: > > 2 GB/64 Bytes * 2.62 ms = 2^31 / 2^6 * 2.62 ms = 87912 secs > > So our choices correspond to one complete scrub of DRAM per day. Our > settings scrub the L2 cache more often: about once every half hour. > Just modify the calculation above, using 1MB instead of 2GB, and 84 ms > instead of 2.62 ms. One finds that the L2 cache is scrubbed about once > every 1376 seconds (every 23 minutes). > > Cheers, > Bruce -- Stephen Mulcahy, Applepie Solutions Ltd, Innovation in Business Center, GMIT, Dublin Rd, Galway, Ireland. mailto:[EMAIL PROTECTED] mobile:+353.87.2930252 office:+353.91.751262 http://www.aplpi.com _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
