View Full Version : 4GB RAM and applications

02-06-2005, 07:25 AM
I have read multiple threads about the /3GB switch and a lot of stuff on other sites, but I really would like some experiences from people with 4GB RAM in their machines.

When setting up a render task in the background that uses 2GB RAM, how much RAM is available when you start PhotoShop, AfterFX, another LW session or a second render task at the same time ? If I start up 2 seperate render processes (MAX, Lightwave or whatever) how much memory can be assigned/asked by each process, at the same time of course?

Normally if you have 4 GB RAM and an application uses 2GB, the other 2GB goes to the Kernel. Compared to a system that ONLY has 2GB physical RAM, is there a performance hit just by having the 4GB ?

Does anybody know which applications will have problems by setting the /3GB switch, supposing your system is fully "/3GB"-compliant ?

Thanks !!

02-06-2005, 09:49 AM
Well, I don't have 4GB in my workstation so I'm not speaking from experience but my understanding is that with the /3GB switch enabled, supported applications can access up to 2GB RAM for their own uses - of the total 4GB, Windows keeps around a gig for itself meaning you have 3GB to split between your apps.

As far as stability goes, I do have the /3GB switch enabled even though I only have 2GB in my workstation (Eyeon's DFX+ recommends that even systems with 2GB installed should have the switch enabled for compatibility reasons) - I haven't encounted any problems as a result.

Hope that helps - let us know how you get on :)

02-06-2005, 10:00 AM
Aegis, thanks for your opinion. I know for sure that MAX and MAYA(for example) can access 2.5-2.7GB when the /3GB switch is enabled.

About stability: lots of applications crash when they REACH the 2GB limit. The /3GB switch can help preventing these applications from crashing. Other applications may become unstable however, even when not reaching the limit.

So that is why I want real 4GB user exerperiences about stability and RAM use on multiple applications. We're NOT gonna spend a lot of money upgrading machines from 2Gb to 4GB based on opinions only;)

Chris S. (Fez)
02-06-2005, 10:34 AM
Interesting. I would like an answer as well. I have two workstations with 2GB, both windows 2000. Is the "3GB switch" available only for XP?

02-06-2005, 05:01 PM
With 4gigs of ram in my comp it always shows that I have about 3.7 gigs. The actual reported size fluctuates when I update the bios.

I only have Lightwave/Modeler and Photoshop running. Sometimes Maya PLE is going too. But it's really snappy when you have Lightwave rendering, and you're doing other things.

02-06-2005, 05:41 PM

In taskmanager it shows PS and LW: if you keep both apps running how much memory can each process use ? Could you try to push them both to the MAX ?

Just make 10000x10000pixels color gradient picture in PS and make 10 duplicate layers and a 10000x10000 render in LW ;)

02-06-2005, 06:15 PM
Photoshop will not let me use more than 1.7gigs of ram. Modeler used like 80mb the dropped down to 4mb, Layout used 1.2 gigs max, but dropped down to 50mb in the middle of the render. It's really hard to get it to sustain 1.2 gigs more than a second or two.

Maya PLE used 30mb, then dropped down to 4mb.

I was able to switch between the apps with no problem.

02-07-2005, 12:46 AM

If what you say is true, then I wonder what's the real use of 4GB. Actually if you do NOT consider the /3GB switch even then 3GB of RAM is hard to justify.

It seems that it is not possible to assign more then 2GB of RAM in total to all applications running. You can run two render tasks in two seperate processes fine, without performance hit, if both do NOT use more then 1GB per task.

However I still do NOT understand what is happening. Suppose you set your Windows swap as small as possible (100MB). Normally when you start an application that needs more then the available VMM, you will receive an error message that you need a large swap file and your system/application will come to a halt. In your case it seems that the applications can not use more then 2GB, but they are still ALLOWED to: but depending on what ? If Layout's memory use is suddenly dropped from 1.2GB to 50MB (!!!), where is the content of this memory placed ? In the Kernel Memory (!?!) or to a swap (this could result in a big performance hit) ? Do you need to change priority to get all memory back to Layout from Photoshop ?

Again: What's the use of all this memory if even the maximum assigned memory for ALL processes is 2GB ?

02-07-2005, 03:44 AM
AFAIK the max for winXP is 2GB, for higher access a 64bit processer and XP64bit is required.

02-07-2005, 11:45 AM
The Max amount of ram my machine has used was 2.8 gigs. I am sure Windows can use more, but I just can't get a test going where it will.

I noticed WinXP will give the most ram to the app that's currently being used, which is something I read a while ago. So it seems to be working. Having a lot of video/audio/2D image editing apps will need 3.5 gigs of ram to run well.

If I had access to a large 3D scene scene with a ton of textures, I am sure LW will use a lot more ram.

The fact that LW is two seperate apps, really helps with the spreading of ram/power.

02-07-2005, 12:31 PM
I dont know about the Wintel people, but you could always get a PowerMac G5 and access 8GB Ram - 4GB per app. With Tiger, that will increase to all available memory.

02-07-2005, 12:45 PM
That's a good idea!!! Trick, go buy a Mac!! It's about $6000 with 8 gigs from Apple... you don't want an AMD with 16 gigs of ram for about the same price... nah.

I like Macs BTW, I just could not resist the post that made no contributions to finding an answer...

But really, the question is "Is 4+ gigs of ram really needed?". I can't do complete tests because I can't get LW to use a sustained 1.5 gigs of ram. If anyone has a scene that's a true monster and would make me poop meh pants, IM me, I'd be glad to test this.

It's easy for me to get Photoshop to suck up 1.7 gigs of ram, I just need to get LW up to that.

I thought maybe I can just have a scene with 100 of those heads. I dunno, how can I wip up a scene that can do this?

02-07-2005, 04:22 PM
I've got 1.5 Gs on my G5 now. Ram is fairly cheep, just wonderring if it's really worth adding another Gig. I tend to think I could spend the money better on other things.

02-07-2005, 06:51 PM
I think 2~3 gigs is the max you should need ram wise. It's not every day that I have Maya, Lightwave, Modeler, Photoshop open at the same time. And it's always low-res stuff for games, or a single model. A few times a year I have to make a huge model with a large amount of textures.

But the room I have is great so that the system and my apps are not fighting over memory all the time. Moving from app to app is fast.

With the push for 64bit, and LW going 64 bit, it's going to make a lot of LW artist very happy with the increased power and speed.

02-07-2005, 09:33 PM
I dont know about the Wintel people, but you could always get a PowerMac G5 and access 8GB Ram - 4GB per app. With Tiger, that will increase to all available memory.
what a smart comment.
as some other people said, ram is cheap but 8Gb is not (from any company) and when you upgrade more than 1 computer, it gets really really expensive, and anyway LW can handle 2Gb max right now.

we have 4Gb on our renderboxxes, and we usually run 2 nodes of LW and 2 nodes of another program on it.
it works great.
but it really depends on what kind of project you do, some of our projects would
be fine with only 1Gb per processor.. others which requires high-polys objects
and satelite imagery require extra ram..
I saw your renderings trick, and I think you will love the extra ram.
like I said in my email, upgrade 1 machine and see if you are happy how it behaves..then upgrade the rest..

02-07-2005, 10:08 PM
We have 4Gb on our renderboxxes, and we usually run 2 nodes of LW and 2 nodes of another program on it.I noticed someone running like that when I went to visit them, like you said, runs good.

02-08-2005, 12:17 AM
Thanks all, especially JML for your experiences.
I got a good deal with our supplier which I surely can't ignore.

About Mac: I love them and I hate them; in the end they will collect dust because of the unpredictable behaviour on huge projects and the lots of unsupported plugins and utilities we need :( And I firmly believe it will take centuries before they are on par with PC's.

02-10-2005, 04:45 PM
I'm interested in finding out more about this. I have a Dell Precision Workstation with 4 gigs installed. I'm using Lightwave, Maya and ZBrush so its pretty easy to create a model and displacement map that can choke my system.

I'm a recent Mac to PC migrator so I'm not up to speed on how to install something like the 3 gig Swtich. Are there any step by step online resources for this?

Thanks in advance!

02-10-2005, 04:57 PM
I got it from here (http://www.chaoticdimension.com/forums/phpBB2/viewtopic.php?t=5014&highlight=3gb)
I hope you will have access ;)

02-10-2005, 05:03 PM
For anyone interested here is a link to a FAQ about the 3GB Switch. (http://www.eyeonline.com/Web/EyeonWeb/Support/TechFAQ.aspx#15)

I'm going to take a crack at it. I was under the impression a software patch needed to be downloaded; instead the vital info is in the boot.ini file.

02-14-2005, 03:09 PM
Didn't work at all; nothing but crashes.

02-14-2005, 03:45 PM
If there are a lot of crashes, then there are some drivers that are not fully certified... :(

02-14-2005, 03:48 PM
that can identify quickly which drivers are certified?

02-14-2005, 04:09 PM
that can identify quickly which drivers are certified?

02-15-2005, 01:26 PM
Hey All,

Just wundering on how you guys / gals got the switch working, iv tryed it but my system frezzes until i restore the boot.ini

Any help would be great... :p