3gb Switch XP Pro and T2 - Crashes and Questions

[rmfrase]

I've now got 6GB Memory for my Dell T7400 Dual Xeon Quad Core system.
Attempting to render an image greater than 9000 x 4500.  My target is to have an image at least 12,000 x 6,000

I'm receiving error messages and the program Crashes:

"Runtime Error!
Unable to allocate memory for subdiv cache.  You may be able to avoide this error by reducing the subdiv cache in your render settings"

Ok, so I reduce the subdiv cache.  And when I do I then get this error message:

Size of subdiv cache per thread is only 75MB (300/4) which could reduce performance. You may want to increase
the size of the subdivcache or reduce the number of threads.

I've read up on the 3/GB PAE Switch, and am unable to tell if it's either on or off. Running Windows XP Pro Service Pack 3.

I've tried various number of cores and threads - but same results (Crash.)
I've also tried Cropping and runing portions of the image  - same results. (Crash.)

Any suggestions?

I will say that I'm currently runing the nice "Advanced Cloud Test" image submitted by Blonderator (nice image by the way.)
Running it at the 1500x1125 size,  8 cores, 800mb Cache, [ ] Preallocate subdiv cache unchecked
And it's almost fishished at 14hrs.

[Oshyan]

Rendering at those sizes is going to need a lot of memory to be sure. Running a 64 bit version of Windows would be your best bet, but the /3gb switch ought to help at least. The key is to determine whether the switch is active. I would suggest trying to render your problem scene and monitoring the memory use of the task in the process list of task manager. If it goes over 2GB then the switch is probably working. We have also found that there are diminishing returns in performance when using more than 4 cores due to overhead, and since more cores uses more memory you might considering using 4 or even less cores, even though it would theoretically take longer. In the case of 4 vs. 8 cores, 8 is often not much, if any, faster than 4, and it uses twice as much memory.

Let us know if any of that helps or if you can provide any more information (such as whether the process memory use does go above 2GB).

- Oshyan

[rmfrase]

Here are my quick results:

Cores: 4
Max Threads: 4
Size: 9000 x 4000
Subdiv Cache: 400Mb  and then used 800Mb
Process Memory Usage: 660,000
Total Memory 3,405,388K
Physical available Memory: 720,000K

Crashed at 00:01:22s at 400mb
Crashed at 00:00:32s at 800mb

[Oshyan]

Quite honestly I have never tested a render that size. I am testing now to see if it's possible in my configuration - 64 bit OS and 8GB of RAM (4 cores).

- Oshyan

[jo]

Hi,

My guess is that you won't be able to render an image that large. With the OS X version there wasn't the same memory restrictions as with Windows, and you could use more like 3.2-3.3 GB but you still couldn't render images anywhere near that large. Interesting to see what Oshyan finds out though.

Regards,

Jo

[Oshyan]

I rendered a *simple* image successfully at 9000x4000, but was unable to go higher, and trying to duplicate the results in the same session were unreliable. This was with default settings though, 4 cores. Memory use never got much above 2GB, so it doesn't seem like it's a memory issue. Jo, do you know what would be limiting this?

- Oshyan

[rmfrase]

Thanks for your help, I tried a "simple" image (the one used for Benchmark) and it crashed repeatedly (9000x4000) - but not all at once.
Some ran for several hours and had most of the initial grid area plotted out  - then crashed.

[MooseDog]

afaik....for 32bit windows, the 3g switch helps the os see more than 2g.  for any individual app to see and use more it must be, in microsoft-speak, "IMAGE_FILE_LARGE_ADDRESS_AWARE".  don't know if tg2 posseses this trait or not.  i know that lightwave does and photoshop does not.  so it's possible that tg2 just cannot see your extra ram.

the goddess ms herself speaks: 

http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

[Oshyan]

Technology Preview 4 is "Large Address Aware". It seems like these sorts of renders are just on the edge of what TG2 can do at this point. But clearly for use in high-end print it will be useful in the future to go to this level. A 64 bit version should help a lot (planned for the future).

- Oshyan

[rmfrase]

I've finally been able to get to the point (after a lot of googlin and reading)  where I've been able to modify the Boot.ini file using the config.exe and bootcfg.exe commands.

And am now using the MaxMem 3000 entry.

We'll see how it goes with different settings.   But so far not looking to good.

[MooseDog]

Technology Preview 4 is "Large Address Aware"....

fantastic!  :thumbsup:

[jo]

Hi Oshyan,

I rendered a *simple* image successfully at 9000x4000, but was unable to go higher, and trying to duplicate the results in the same session were unreliable. This was with default settings though, 4 cores. Memory use never got much above 2GB, so it doesn't seem like it's a memory issue. Jo, do you know what would be limiting this?

I was also able to render a 9000 x 4000 image, but it was only the default scene. That surprised me anyway, I'm sure a while back I wasn't able to render even that successfully. Memory use seemed to top out at about 2.2 GB. I don't know much about the specifics of memory use during rendering, I'm afraid.

Regards,

Jo

[rmfrase]

Currently, the 9000x4000 render has been going for 14hrs and no problems as of yet.

Running (3) Cores
Mem Usage: 1,685,228K
Detail 0.6
Max Threads 3
Subdiv Cache 300

I've got fingers and toes crossed, but it's hard to walk with toes crossed....

[rmfrase]

Well, it finally Crashed.  Running (4) cores and smaller size 6000x3000.
Also had "Patch-Work" of uneven lighting even after installing lastest release.


I've tried....


I guess I'm going to wait a while until the program is stable.