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

On 19/08/2010 12:23, Philippe Rimbault wrote:
> 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
>
>
>
>
>
I've re-init the pgbench with -s 400 and now server work (very) better
than desktop.
So ... my desktop cpu is faster if i only work with small query but
server handle better heavier loads.
I was just suprise about the difference on my small database.

Thx