Re: Same query taking less time in low configuration machine

[Vishwa Kalyankar <vishwakalyankar8@xxxxxxxxx>]

Hi,

  I am pasting the output of both server cpu speed and memory speed, and we have same os (centos) on both the machines and i have downloaded the postgres rpms from https://www.postgresql.org/

 

 1) High end machine

 [root@localhost ~]# dmidecode -t processor | grep Speed
        Max Speed: 3600 MHz
        Current Speed: 2666 MHz
        Max Speed: 3600 MHz
        Current Speed: 2666 MHz

Ram slots 16x4=64 GB

[root@localhost ~]# dmidecode --type 17
# dmidecode 3.1
Getting SMBIOS data from sysfs.
SMBIOS 2.6 present.

Handle 0x1100, DMI type 17, 28 bytes
Memory Device
        Array Handle: 0x1000
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 16384 MB
        Form Factor: DIMM
        Set: 1
        Locator: DIMM_A1
        Bank Locator: Not Specified
        Type: DDR3
        Type Detail: Synchronous Registered (Buffered)
        Speed: 1333 MT/s
        Manufacturer: 00CE00B380CE
        Serial Number: 35E9FC94
        Asset Tag: 02131263
        Part Number: M393B2G70BH0-YH9
        Rank: 2

 cache size      : 12288 KB

2) Low End machine

[root@localhost ~]# dmidecode -t processor | grep Speed
        Max Speed: 3800 MHz
        Current Speed: 3200 MHz

Ram slots 4x2=8GB

[root@localhost ~]# dmidecode --type 17
# dmidecode 3.0
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.

Handle 0x0038, DMI type 17, 34 bytes
Memory Device
        Array Handle: 0x0037
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 4096 MB
        Form Factor: DIMM
        Set: None
        Locator: DIMM1
        Bank Locator: Not Specified
        Type: DDR3
        Type Detail: Synchronous
        Speed: 1600 MHz
        Manufacturer: Hynix/Hyundai
        Serial Number: 0BB0390C003C
        Asset Tag: 9876543210
        Part Number: HMT351U6EFR8C-PB
        Rank: 2
        Configured Clock Speed: 1600 MHz

  cache size      : 6144 KB

  Any other details required? kindly let me know how to obtain those, i will share you the same.

Regards,

Vishwa S Kalyankar

 

On Tue, Jul 14, 2020 at 10:12 PM Kenneth Marshall <ktm@xxxxxxxx> wrote:

On Tue, Jul 14, 2020 at 09:27:56PM +0530, Vishwa Kalyankar wrote:
> HI,
>
> OS cache is updated and I had run the query few times with almost the same
> result each time.
>
> Regards,
> Vishwa

Hi Vishwa,

What are the CPU speeds, memory bandwidth, I/O bandwidth? Often the
lower core count CPUs have a faster clock speed. What is the CPU cache
size for both? Are you running the same OS and PostgreSQL build binaries
on both?

Regards,
Ken