IPP on Windows XP on machines with intel AVX instruction extension

[C_H_W_]

Hi, Would like to ask a question on running intel IPP 7.1 on machines with intel AVX instruction extension. We are trying to get a intel Xenon E5 series processor(with intel AVX instruction set extension) for our project. However, due to legacy issues, we have to adopt Windows XP as our OS. Understand that in order to utilise intel AVX instruction sets, we would need to have Windows 7 SP1 as the OS. Would we still be able to utilise intel IPP7.1 (can the processor default to older SSE version)? What is the type of shortcomings or performance hit(or maybe workaround) if I would to do so? Likewise I would require advice if in such a situation, would it be better to adopt an older version of the IPP library? Thanks in advance

[SergeyKostrov]

I would also ask a question on some Microsoft's forum: Does Windows XP ( 32-bit or 64-bit ) support AVX? It looks like No. There are lots of links on the web related to that subject and one of them is: http://software.intel.com/en-us/forums/topic/284486 Please take into account that almost everybody will try to advise you to upgrade Windows XP to Windows 8 or Windows 7. Microsoft is trying to do it for a couple of years since release of Windows Vista. Don't you remember that Windows "disaster"? I also wouldn't expect a SP4 for Windows XP and as a compromise IPP functions based on SSE4.x instructions could be used on your project.

[SergeyKostrov]

Here are a copuple of more links: http://forum.sysinternals.com/why-does-avx-cpu-extension-need-os-support_topic22909.html and http://en.wikipedia.org/wiki/Advanced_Vector_Extensions

[C_H_W_]

Sergey Kostrov wrote:

Please take into account that almost everybody will try to advise you to upgrade Windows XP to Windows 8 or Windows 7. Microsoft is trying to do it for a couple of years since release of Windows Vista. Don't you remember that Windows "disaster"?

Tentatively planning to do an upgrade but unfortunately it will be two-three years down the road

Sergey Kostrov wrote:

I also wouldn't expect a SP4 for Windows XP and as a compromise IPP functions based on SSE4.x instructions could be used on your project.

So this means that IPP library will default to use older SSE (eg SSE4.2) on an Sandy Bridge Processor running with Windows XP? So we can safely use the latest IPP 7.1?

[SergeyKostrov]

>>...Tentatively planning to do an upgrade but unfortunately it will be two-three years down the road... Take into account that Microsoft will support WIndows XP until 2014 and Windows 7 until 2020 or so. >>...So we can safely use the latest IPP 7.1? Yes. But you need to evaluate performance of IPP anyway. It is absolutely not clear what IPP domains you're going to use. >>...What is the type of shortcomings or performance hit (or maybe workaround) if I would to do so? See my statement above. My next question is do you have an application that uses IPP functions?

[C_H_W_]

Thanks for your help!

I have some Computer Vision application code written with OpenCV, intending to compile the code in conjunction with IPP 7.1, taking advantage of the speedup it offers

[SergeyKostrov]

>>...I have some Computer Vision application code written with OpenCV, intending to compile the code in conjunction with IPP 7.1... OpenCV functionality is designed on top of IPP functions and because of this there could be some performance impact. IPP is highly optimized but OpenCV API is not. So, some speed ups from using IPP functions implemented in assembler could be devaluated by OpenCV functions implemented in C/C++. It is really hard to predict anything now.

[C_H_W_]

yup! That's the reason I am concerned with whether I could use the IPP7.1 on system(running with Win XP) with Intel AVX instruction extension, running on Win XP. Could the IPP library use older instruction set when it can't use intel AVX?

[SergeyKostrov]

>>...Could the IPP library use older instruction set when it can't use intel AVX? IPP should handle it properly and please read it: Intel article: Understanding CPU Dispatching in the Intel® IPP Library Web-link: http://software.intel.com/en-us/articles/intel-integrated-performance-primitives-intel-ipp-understanding-cpu-optimized-code-used-in-intel-ipp