Exceeding 2GB limit

[PorcupineFloyd]

I've been doing some research about /LARGEADDRESSAWARE switch and it looks like it's a switch used when compiling, and together with information found in release notes of TG2 (from TP4 till now) it is supported. If so then why my TG2 uses only 2GB of RAM despite setting subdiv cache to 2048 or higher and rendering in 3000 x 2000? I have 8 GB of RAM and I'm under Vista HP. Am I missing something?

[cyphyr]

Not sure if your missing something or not but the subdivide cache should be multiplied by the number of cores your using so a 2048mb cache would need 4096mb on a dual core and 8193mb on a quad (or thereabouts). On my machine (see below)I cant really set my sd cache to more than 800mb.
Also please correct me if I misunderstand the SD cache usage.
Richard

[PorcupineFloyd]

As far as I understand - subdiv cache is divided by max number of threads specified. So if you have four cores and set subdiv cache to 2048, each core (thread) will be able to use 512 mb.

[jo]

Hi,

I'm pretty sure if you're using 32 bit Vista you still need to enable the /3GB switch before applications can access more than 2 GB. I don't know how to do this myself, it's different in Vista than XP, but I did find some info about it on a web search recently. On 64 bit Vista apps with /LARGEADDRESSAWARE automatically get upped to a 4 GB limit.

Regards,

Jo

[PorcupineFloyd]

I have 64 bit OS but still - I've never seen TG2 go over 2GB limit.

[RArcher]

TG only uses as much RAM as it needs depending on your scene.  Add a dozen or so populations of complex trees, grasses, bushes, etc. and I can guarantee you will see it top out just under 4gb.

[neuspadrin]

have you done a high enough quality render with objects needing that much space?  Ive seen my terragen with 3 almost 4 gigs used.  never had to change any of the settings.

*got beat to it somewhat by RArcher*

[PorcupineFloyd]

That's really strange as I was doing pictures even in 3600 x 2400 with lots of xfrog trees and TG2 was always stuck at 2GB. What I've also found is that when renderer reaches 2GB after a constant increase - render process slows down (although I would need someone else to confirm it as it may just be my very subjective opinion on this matter).

Geez it's nearly 6 AM in the morning... It'll be a long day

[jo]

Hi,

That's really strange as I was doing pictures even in 3600 x 2400 with lots of xfrog trees and TG2 was always stuck at 2GB. What I've also found is that when renderer reaches 2GB after a constant increase - render process slows down (although I would need someone else to confirm it as it may just be my very subjective opinion on this matter).

Just a random stab in the dark, do you have your page file set to 2 GB or something?

Regards,

Jo

[PorcupineFloyd]

Errr (shall I hide under the desk now? ) - yes. Exactly 2GB. Pure 2048MB in one chunk.

But... What's the connection between virtual and physical memory in this case (while I have 8192MB of physical RAM)?

[Oshyan]

Floyd, don't increase the render buffer size unless you have very good reason to do so. The default should be fine and will leave more memory available for other needs. But it sounds like you're not really seeing any clear issues resulting from memory limitations anyway. I wouldn't think the 2GB page file setting would cause an actual limitation - after all page file should only be used once physical memory runs out. I know at least that x64 Vista does allow for TG2 to use more than 2GB of RAM as I run this setup myself.

- Oshyan

[PorcupineFloyd]

I've increased virtual memory to 4GB. However I wasn't testing it yet on such a big image to determine if it's exceeding 2GB or not. Thanks for some clues