On 5/12/09 11:08 PM, "Arjen van der Meijden" <acmmailing@xxxxxxxxxxxx> wrote: > We have a dual E5540 with 16GB (I think 1066Mhz) memory here, but no AMD > Shanghai. We haven't done PostgreSQL benchmarks yet, but given the > previous experiences, PostgreSQL should be equally faster compared to mysql. > > Our databasebenchmark is actually mostly a cpu/memory-benchmark. > Comparing the results of the dual E5540 (2.53Ghz with HT enabled) to a > dual Intel X5355 (2.6Ghz quad core two from 2007), the peek load has > increased from somewhere between 7 and 10 concurrent clients to > somewhere around 25, suggesting better scalable hardware. With the 25 > concurrent clients we handled 2.5 times the amount of queries/second > compared to the 7 concurrent client-score for the X5355, both in MySQL > 5.0.41. At 7 CC we still had 1.7 times the previous result. > Excellent! That is a pretty huge boost. I'm curious which aspects of this new architecture helped the most. For Postgres, the following would seem the most relevant: 1. Shared L3 cache per processors -- more efficient shared datastructure access. 2. Faster atomic operations -- CompareAndSwap, etc are much faster. 3. Faster cache coherency. 4. Lower latency RAM with more overall bandwidth (Opteron style). Can you do a quick and dirty memory bandwidth test? (assuming linux) On the older X5355 machine and the newer E5540, try: /sbin/hdparm -T /dev/sd<device> Where <device> is a valid letter for a device on your system. Here are the results for me on an older system with dual Intel E5335 (2Ghz, 4MB cache, family 6 model 15) Best result out of 5 (its not all that consistent, + or minus 10%) /dev/sda: Timing cached reads: 10816 MB in 2.00 seconds = 5416.89 MB/sec And a newer system with dual Xeon X5460 (3.16Ghz, 6MB cache, family 6 model 23) Best of 7 results: /dev/sdb: Timing cached reads: 26252 MB in 1.99 seconds = 13174.42 MB/sec Its not a very accurate measurement, but its quick and highlights relative hardware differences very easily. > I'm not really sure how the shanghai cpu's compare to those older > X5355's, the AMD's should be faster, but how much? > I'm not sure either, and the Xeon platforms have evolved such that the chipsets and RAM configurations matter as much as the processor does. > I've no idea if we get a Shanghai to compare it with, but we will get a > dual X5570 soon on which we'll repeat some of the tests, so that should > at least help a bit with scaling the X5570-results around the world down. > > Best regards, > > Arjen > -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
