LAHF/SAHF and PrefetchW

[NKoul1]

I would like to know the first Xeon to support the LAHF/SAHF and PrefetchW ?

Is there a way to query the Intel processor finder for specific feature support ?

[Kevin_M_Intel]

Hello Irwindale,

At this point I do not have the information handy but let me research and I will be back soon with more information.

[NKoul1]

Hi Kevin, thanks let me know if you find it then.

There should be a comparison table, it would be helpful ! ...especially since the new requirements for Windows 8.1.

[Kevin_M_Intel]

Hi Irwindale,

Thanks for waiting. LAHF and SAHF are part of Intel Virtualization Technology (Intel VT-x). For Xeon CPU's, VT-x was introduced with the Clovertown family. You can a list of Clovertown CPU's here:

http://ark.intel.com/products/codename/23349/Clovertown?q=clovertown http://ark.intel.com/products/codename/23349/Clovertown?q=clovertown

These CPU's launched starting in 2006 and any cpu (xeon or Core) that supports VT-x will support LAHF/SAHF; however, it is important to mention that not all Xeon or Core (1st gen, 2nd gen, 3rd gen, 4th gen) support VT-x.

In regards the PrefetchH it is supported in all Xeon CPU's.

[Jeffrey_H_Intel]

The question was about PREFETCHW, not PREFETCHH. PREFETCHW will be added in the Intel Broadwell family of processors, per https://www-ssl.intel.com/content/www/us/en/embedded/products/broadwell-u/5th-gen-core-mobile-u-processor-platform-brief.html 5th Gen Intel® Core™ Processors (Mobile U-Processor) Platform Brief.