Re: Performance on new 64bit server compared to my 32bit desktop

On 19/08/2010 11:51, Scott Marlowe wrote:
> On Thu, Aug 19, 2010 at 2:07 AM, Philippe Rimbault<primbault(at)edd(dot)fr> wrote:
>
>> Hi,
>>
>> I'm having a strange performance result on a new database server compared to
>> my simple desktop.
>>
>> The configuration of the new server :
>> - OS : GNU/Linux Debian Etch x86_64
>> - kernel : Linux 2.6.26-2-vserver-amd64 #1 SMP Sun Jun 20 20:40:33 UTC
>> 2010 x86_64 GNU/Linux
>> (tests are on the "real server", not on a vserver)
>> - CPU : 2 x Six-Core AMD Opteron(tm) Processor 2427 @ 2.20GHz
>> - RAM : 32 Go
>> The configuration of my desktop pc :
>> - OS : GNU/Linux Debian Testing i686
>> - kernel : Linux 2.6.32-5-686 #1 SMP Tue Jun 1 04:59:47 UTC 2010 i686
>> GNU/Linux
>> - CPU : Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz
>> - RAM : 2 Go
>>
> PERFORMANCE STUFF DELETED FOR BREVITY
>
>
>> Do you think it's a 32bit/64bit difference ?
>>
> No, it's likely that your desktop has much faster CPU cores than your
> server, and it has drives that may or may not be obeying fsync
> commands. Your server, OTOH, has more cores, so it's likely to do
> better under a real load. And assuming it has more disks on a better
> controller it will also do better under heavier loads.
>
> So how are the disks setup anyway?
>
Thanks for your reply !

The server use a HP Smart Array P410 with a Raid 5 array on Sata 133 disk.
My desktop only use one Sata 133 disk.
I was thinking that my simples queries didn't use disk but only memory.
I've launch a new pgbench with much more client and transactions :

Server :
postgres$ pgbench -c 400 -t 100
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 400
number of transactions per client: 100
number of transactions actually processed: 40000/40000
tps = 115.054386 (including connections establishing)
tps = 115.617186 (excluding connections establishing)

real 5m47.706s
user 0m27.054s
sys 0m59.804s

Desktop :
postgres$ time pgbench -c 400 -t 100
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 400
number of transactions per client: 100
number of transactions actually processed: 40000/40000
tps = 299.456785 (including connections establishing)
tps = 300.590503 (excluding connections establishing)

real 2m13.604s
user 0m5.304s
sys 0m13.469s