Popcount emulation for x64 process - RAM memory limit

Jon_D_ · ‎05-23-2017

Hello,

I'm trying to use Intel Software Developement Emulator to emulate popcount instruction for my CPU (Core2Quad Q6600). I need this to run Quantum Break game, which requires ppcount.

Game runs, but very, very slow. I noticed, that no matter what QuantumBreak.exe uses max around 2,5 GB of my RAM memory (I have 8 GB), so that can be casue of huge slowdown. As far as I know 2,5 GB is a limit for single 32 bit process in Windows systems, but why this limitation occurs since game is x64 and my system too? I tried on Windows 7x64 and Windows 10 x64 - same results.

To check if it's not a game problem/bug I've used sde with different game (GTA V). Normaly it uses around 5 GB of RAM, but with sde again only 2,5 GB, so there is some kind of limit.

How this can be bypassed? I red -help and -help-long but haven't found anything useful in those switches.

Any help would be much appreciated.

Best Regards

SergeyKostrov · ‎05-23-2017

There are no any RAM limits for SDE on a 64-bit platform. On a KNL system with a 64-bit Red Hat Linux in a series of stress tests SDE was able to work when almost all memory was allocated ( a couple of MB less than 96GB ). >>...As far as I know 2,5 GB is a limit for single 32 bit process in Windows systems, but why this limitation occurs since game is x64 and >>my system too? A limit for a 32-bit applications on a Windows is 2GB, or 3GB when special techniques used on some server like Windows OSs, even if the application is executed on a 64-bit platform.

Jon_D_ · ‎05-24-2017

Thanks for answer.

For Linux there are two sde. Sde and sde64. For Windows there is only sde, which is 32 bit application. Both games are 64bit only - I double check it.

How can I test if sde can use all my memory? Maybe some testing app? Perhaps something else (like video card driver) is causing memory limit, so I have to chek if sde is capable of using all of my RAM.

SergeyKostrov · ‎05-31-2017

>>...How can I test if sde can use all my memory? Maybe some testing app? Implement a simple 64-bit test ( a couple of code lines ) that calls malloc CRT function and allocates memory up to a limit of your system.