Re: Slow Performance on a XEON E5504

Hello List,

I've got a system on a customers location which has a XEON E5504 @ 2.00GHz Processor (HP Proliant)

It's postgres 8.4 on a Debian Squeeze System running with 8GB of ram:

The Postgres Performance on this system measured with pgbench is very poor:

transaction type: TPC-B (sort of)

scaling factor: 1

query mode: simple

number of clients: 40

number of transactions per client: 100

number of transactions actually processed: 4000/4000

tps = 158.283272 (including connections establishing)

tps = 158.788545 (excluding connections establishing)

The same database on a Core i7 CPU 920 @ 2.67GHz, 8 cores with 8GB RAM same distro and Postgresql Version is much faster:

transaction type: TPC-B (sort of)

scaling factor: 1

query mode: simple

number of clients: 40

number of transactions per client: 100

number of transactions actually processed: 4000/4000

tps = 1040.534002 (including connections establishing)

tps = 1065.215134 (excluding connections establishing)

Even optimizing the postgresql.conf values doesn't change a lot on the tps values. (less than 10%)

Tried Postgresql 9.1 on the Proliant:

transaction type: TPC-B (sort of)

scaling factor: 1

query mode: simple

number of clients: 40

number of threads: 1

number of transactions per client: 100

number of transactions actually processed: 4000/4000

tps = 53.114978 (including connections establishing)

tps = 53.198667 (excluding connections establishing)

Next was to compare the diskperformance which was much better on the XEON than on the Intel i7.

Any idea where to search for the bottleneck?

Regards, Felix.
There are many question there:
- Are you using the same disc models in both systems (Xeon and Intel i7)?
- Which are the values for work_mem, shared_buffers, maintainance_work_men, effective_io_cache, etc ?
- Is PostgreSQL the unique service in these servers?

My first advice is that PostgreSQL 9.2 was released today, which has a lot of major performance improvements, so,
you should update your both installations to this new version to obtain a better performance, security and stability.

Best wishes

Mit freundlichen Grüßen

Felix Schubert

FEScon

... and work flows!

felix schubert

haspelgasse 5

69117 heidelberg

mobil: +49-151-25337718

mail: input@fescon.de

skype: fesmac