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Posted: Thu May 09, 2013 5:31 am
by jcomm
Reading KOSTA's guide I see it is NOT required in the CFG, but other sources list it as usefull in P3d v1.4

I'm confused :-/

Should or shouldn't I include the HIGHMEMFIX=1 in the CFG file?

Posted: Thu May 09, 2013 10:14 am
by BobbyHipperson
You may find this thread helpful

Hello all,

This is a depricated hold over from the days of early gen d3d9 when 512MB was high-end. We do still read HIGHMEMFIX in from the config in the old d3d9 rendering system, but we never use it. We've moved to the new D3D11 rendering system internally, so I had to dust off an old branch to verify that HIGHMEMFIX even existed :) . Take it from someone who accidentally leaked 4GB of render targets onto his graphics card - which coincidentally causes the entire world to collapse into a black-hole-like vortex of doom - that we have no problems using up lots graphics memory. In theory we can use more graphics memory than system memory, because even with large address aware, the app gets capped at around 3.5 GB while directx manages the graphics memory independently, allowing it to max out the memory on the card.



Prepar3D Software Engineer

Posted: Thu May 09, 2013 10:24 am
by jcomm
Hi Bobby,

Thx for your reply!

Yes, I did find that post when I searched in the forum, but, I must confess that I didn't really get the answer from it :-(

Apparently Beau is suggesting that the HIGHMEMFIX entry although it get's read from CFG is not used, but then he shifts the focus to the newer versions (DX11-based) they are currently using for development internally, so, in the end I confess I got confused and couldn't figure out if I really should or should not, include that entry in the CFG file :-/

Posted: Thu May 09, 2013 12:50 pm
by WBard
Thanks for linking that post Bobby.

We don't use highmemfix Jcomm, it's always on now in Prepar3D v1.x.

Posted: Thu May 09, 2013 12:56 pm
by Beau Hollis
Sorry for the confusion in terminology. Here is a slightly revised edition:

The option is obsolete. It gets read in but is never used, so adding it to your Prepar3D.cfg will not have any impact on performance. Back in earlier versions of FS, the system was optimized for cards with less than 512MB or RAM. This option allowed users with high end video cards to enable use of more than 512MB worth of texture and buffer data. We do that by default, so there is no need for this.


Posted: Thu May 09, 2013 2:11 pm
by jcomm
Ok Beau and WBard, now I understand! Sorry for the confusion...

Thank you for your replies ;-)