Performance of 64bit vs 32bit

[Kelvin]

Hi,

I would like to ask if there is any difference in performance running 32 bit vs 64 bit verson to decode jpeg based on jpegView under Xeon (Woodcrest) processor, Window 2003 R2 ?

(i.e. if 32 bit IPP library already make full use of 64 bit hardware ?)

The reason I ask is I got a new machine which comes with 32 bit Windows 2003 OS. If I can double the frame decode per second under 64 bit OS then I will return current OS and buy a new one.

I try to look at the .csv file but it doesn't have performance for 32 bit Xeon machine.

Thanks a lot for you help.

- Kelvin

[TimP]

32-bit operation can't take advantage of the full 64-bit register set, or the 64-bit size of the standard integer registers. However, it's likely that the 32-bit IPP libraries, using SSE registers, give you full performance, if you don't run short of address space in 32-bit operation.

[Kelvin]

Thanks Tim, I think I found the answer from one set of .csx files in x32 and x64 distributions. They are using the same computer SVSIPP018. AlthoughCPU is unknown. I am guessing this is Core Due 2 1888MHz.

From the result both 32 bit and 64 bit gives me same performance. I assume Xeon (Woodcrest) will produce similar result since it is using the same architecture. Actually other results from the files show that 64 bit run 1 to 2% slower than 32 bit in most test. Please correct me if I'm wrong.

SoI will stay with 32 bit Window Server 2003 for now.

Cheers !

- Kelvin

ps_ippjv8.csv
CPU,Unknown 2x1800 MHz
OS,Microsoft Windows Server 2003 (Win32)
Computer,SVSIPP018
Library,ippjv8-5.1.dll, 5.1.1, Jun 17 2006
Start,Sun Jun 18 07:42:31 2006
funcBase,funcDataType,funcDescriptor,Len/Size,Parm1,Parm2,Parm3,Parm4,scaleFactor,Comment,Clocks,per,Time (usec),Interest
jpeg_Decoder,8u,C3,720x480,Jaehne,baseline,YCbCr422->BGR,75,-,nLps=32,36,px,6.99e+003,-
jpeg_Encoder,8u,C3,720x480,Jaehne,baseline,RGB->YCbCr422,75,-,nLps=32,60,px,1.15e+004,-

ps_ippju8.csv

CPU,Unknown 2x1800 MHz
OS,Microsoft Windows Server 2003 (Win64)
Computer,SVSIPP018
Library,ippju8-5.1.dll, 5.1.1, Jun 17 2006
Start,Sat Jun 17 19:04:28 2006

jpeg_Decoder,8u,C3,720x480,Jaehne,baseline,YCbCr422->BGR,75,-,nLps=32,36,px,7.08e+003,-
jpeg_Encoder,8u,C3,720x480,Jaehne,baseline,BGR->YCbCr422,75,-,nLps=32,59,px,1.14e+004,-

[Vladimir_Dudnik]

Yes, just moving to 64-bit calculations does not bring twice faster FPS. Basically, performance depends a lot from any particular function algorithms and level of optimization. You can see some very attractive results in IPP performance data, but they were not got just automatically by moving to 64-bit system.

Vladimir