Memory Size and (3D V4 Performance

[dsymanow]

A question for the experts: does the amount of physical memory affect P3D V4 performance?

I stumbled on this. I've been running P3D V4 with addon-ons that increase the VAS used by the program (e.g., Orbx, PMDG aircraft, Active Sky, etc.). My computer had 16 GB of memory. Performance was fine. Today I added 32 GB (for a total of 48 GB), and I've gotten a significant and unexpected increase in performance in terms of FPS.

I used Task Manager and Resource Manager, and I think this is what is happening. In the benchmark flight I use, and with 16 GB of memory, P3D V4 used about 7 GB of physical memory, and cached about 54 GB of data (i.e., the data is stored on disk). When I added the additional 32 GB, the physical memory usage stayed the same (7 GB), but the cached memory dropped to 7 GB. Committed memory usage increased.

If I understand what is happening, P3D is able to take advantage of the larger amount of physical memory and increase the amount of data kept in physical memory. Of course that is what is expected with a 64-bit app. But what it means is that adding physical memory increases performance if you're using memory intensive add-ons that are forced to cache data on a disk.

What confused me is that, while P3D V4 has about 7 GB allocated directly to it, there is also a larger amount of data used for other data storage. So the amount of memory that fully enables P3D V4 is not 7 GB, but 7 GB plus whatever is needed for your add-ons. In my case it seems that I can use 64 GB. What is a bit misleading is that the 7 GB physical allocation to P3D is not the total VAS used by the program.

Anyway, I invite comments from the exerts, and shared this for those who are looking for a way to take full advantage of the 64-bit capability of P3D.

[AnkH]

Are you sure it is no coincidence? I've already seen a lot of such "observations" that in the end turned out to be random. The only thing is: if you now remove those additional RAM modules again, your FPS should drop. Then it would be really related.