Drivers & Software

[colesdav]

Zen, Zen+ and Zen 2 cannot support SAM due to the lack of full-rate _pdep_u32?
True or false?
Anyone know the answer to this? 

See: https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-dive-review-5950x-5900x-5800x-and-5700x-te...

 Thanks.

[colesdav]

This article seems to confirm: 

https://www.techpowerup.com/275565/amd-ryzen-3000-and-older-zen-chips-dont-support-sam-due-to-hardwa...

Any confirmation from AMD on this one? 

I am still not sure if it correct or not. 

It would be funny if Intel can implement it for my oldest PCs with Haswell 4790K/4770K CPU. 
Hope it works on 3DMark. 

[goodplay]

[colesdav]

I understand the supposed technical details about it in the initial reports and on the article I just posted. 

There have been a number of  people questioning the accuracy of the above reports in relation to SAM support and performance on older Zen processors. 

I guess we all need to wait until AMD provide an official statement about it.

Last BIOS update for Haswell Z97 Motherboards I run was ~ April 2018 for Intel security fixes so I doubt I will ever see an official BIOS from the manufacturer to enable SAM on Haswell processors. 

However there may be BIOS mods available from enthusiast BIOS modders somewhere to enable it. 
For example BIOS mods were done to enable "above 4G decoding" on some Z87 boards.
It did not involve much modification to the BIOS, was simple to do. It worked.