IPP 5.0 Beta: ippsFFTInv_CToC_16s_Sfs SLOW on P4 EE dual core

[dmacd]

Greetings,

ippsFFTInv_CToC_16s_Sfs is about 50% slower in absolute terms on my new P4 Extreme Edition dual core @ 3.2ghz than it was on an older P4 2.4ghz. I nuked the older version of ipp and I know other ipp routines are substantially faster in absolute terms, so what gives? Is 16-bit math out of the question on this processor?

Doing the ifft this way was the main motivation for buying this machine...grr....

Daniel

[Ying_S_Intel]

Dear Customer,
We are investigating this issue vai Intel Premier Support.

Are you runing the program at one core or two cores? Is your application multithreaded or not? Please provide these information in detail and ifpossible a test case via your issue 310553 in Intel Premier Support channel.

Thanks,
Ying S
Intel IPP

[dmacd]

The problem appeared to be due to differing default thread affinities on one core vs two. Disabling HT resulted in more reasonable performance.

My apologies.