XP ram usage...

[maninflash]

The limit is actualy set by the 32-bit technology limitation which doesn't allow softwares to use more than 1.6GB of physical memory, Win XP usualy keeps 500MB reserved for it's own use, so thats why most workstations are built with 2GB memory, there's simply no sense for more, UNLESS, you want to work with two softwares at the same time, Maya and photoshop for example and have large files in both.

anyway, back to your question,

-in start menu > run > type msconfig, click OK
-under BOOT.INI tab, click Advanced Options
-check MAXMEM option and up the number to 3GB

[pwallin]

...which doesn't allow softwares to use more than 1.6GB of physical memory, Win XP usualy keeps 500MB reserved for it's own use, so thats why most workstations are built with 2GB memory

I may not understood this right, but if software can use only 1.6 GB and I have a 2GB installed I waste about 400 Megs? I think it would be better to have just 1,5 GB installed so I just waste about 100 Megs, right?

Pasi

[DorisDay]

Thanks maninflash, I'll give it a try...

The original plan was to use two apps opened, ZBrush & Photoshop, I guess I should have said that...:blush:

But now I have the extra gig, I want to try & squeeze what I can out XP...

Roll on longhorn...:curious:

pwallin (http://www.cgtalk.com/member.php?u=129804): I'm affraid it doesn't work like that, XP will always want around 400MB, so if you only have 1.5Gb installed you only get 1.1Gb, I personally think its ridiculous but what can you do...

[Srek]

I may not understood this right, but if software can use only 1.6 GB and I have a 2GB installed I waste about 400 Megs? I think it would be better to have just 1,5 GB installed so I just waste about 100 Megs, right?

Pasi

It does not work this way. Graphics adapter map their memory into the range below 2 GB. If you have a 512 MB card you loose 512 MB. Add to this what is needed by the codecs you use in your app and you will quickly loose several 100 MB. If you use SLI you will loose TWICE the memory. To the best of my knowledge the very latest chipsets allow to map the memory of the cards in the range above 2GB.
Cheers
Björn

[pwallin]

Ok thanks, must get that extra gig.


Pasi

[maninflash]

I may not understood this right, but if software can use only 1.6 GB and I have a 2GB installed I waste about 400 Megs? I think it would be better to have just 1,5 GB installed so I just waste about 100 Megs, right?

Pasi

Win XP needs 500MB of RAM to work fluently, and usualy doesn't allow softwares to use ITS share unless there is a shortage of memory and even then, uses a combination of scratch disk/virtual memory and physical memory, so if you have 1GB, your softwares have only 500MB total memory to share which isn't enough for 3D applicatins such as Maya or MAX, not even to mention rendering!

However, if you have 3GB memory, XP takes 500MB and you're left with 2.5GB for your softwares to share, so you can easily work with a large scene in Maya and set mentalray to render in the background, or open photoshop and zbrush, etc.

And besides, with RAM as cheap as hamburgers these days, it's always a good idea to have a bit more than you actualy need.

[imashination]

if you have 1GB, your softwares have only 500MB total memory to share which isn't enough for 3D applicatins such as Maya or MAX, not even to mention rendering!

Thats being a bit pessamistic, most people will work with a gig of ram in any 3d app with no problems.

[cJaynes]

And besides, with RAM as cheap as hamburgers these days, it's always a good idea to have a bit more than you actualy need. Man wouldn't it be great if Newegg had a 99 cent menu like wendy's...... haha

[maninflash]

Thats being a bit pessamistic, most people will work with a gig of ram in any 3d app with no problems.

That depends on the type of work you do with your 3D app and your scene data and how complex your character rig is, usualy FX animation needs more than 1Gig to work smooth, specialy particle simulation and water effects, complex characters, with detailed facial controls, also need more than 1Gig to work okay, playblasting in Maya takes a lot of RAM becasue Maya loads the images into RAM and then plays them back in 24 or 30 fps, so if you're low on memory, you're aumaticaly limiting your playblast lenght and have to do multiple sessions.

[DorisDay]

anyway, back to your question,

-in start menu > run > type msconfig, click OK
-under BOOT.INI tab, click Advanced Options
-check MAXMEM option and up the number to 3GB

Sorry to resurrect this but it just isn't happening for me...

I've done the above, but when you change the MAXMEM & then click "APPLY" it changes back to 2048...

Any ideas???

[3Dspline]

I have a question about swap space regarding this... I have 2 gigs on my computer and I need more to get some conversions out of max on really heavy scenes. At the moment windows won't use swap space becouse as soon as it starts using it, its reached its 2gig limit and it crashes, is there a way to allow it to surpase the 2gig limit while not having it as physical memory?

As I understand things, 32bit should allow 4 gigs of ram usage, or am I horribly mistaken?

[ihavenofish]

windows xp 32 bit can "technically" use up to 4gb of virtual memory including 4 gb of physical ram. this is assuming you dont have a xeon with pae extensions.


of that, a single application is limited to a maximum of 2gb of virtual memory. if you enable the /3gb switch in the boot.ini a single app may use up to 3gb virtual memory. the remaining 2 or 1 gb memory is reserved for os functions. running multiple applications at once can squeeze the os into a small corner of the 4gb allowable virtual memory (about 250-300mb for xp pro, 150-200 for 2k... the os doesnt just default to half)

pci express devices have a rather large memory hole, as mentioned, and can swallow up to 1.5gb once you add more than 2gb of memory. most boards can relinquish this memory with a bios setting (setting memory hole mapping to software on the tyan k8we for example).

starting with service pack 2 for xp, as soon as you add 4gb of memory, windows alocates a whopping 1.3gb to pae functions. you are left with 2.7gb. there is nothing that will change this in any setting. if you only have 3gb, or 3.5gb of ram, you will see all of it. (or so the techdoc seems to allude to, i have not tested)

using the /maxmem switch will only alocate as much ram as you actually have (physical ram minus pci memory hole). this is likely why it is bouncing back. this switch is only intended to LIMIT memory use, and when not included, the system defaults to whatever amount you have installed.

enabling pae extensions on a xeon allows the os to alocate alot more ram (up to 64gb on server datacentre) but a single application is still bound by the same rules. you just have the virtue of being able to run many at once.

so, thats the theoretical physical side.

on the practical side, without the 3gb switch enabled, most applications will crash out well before they hit 2gb of virtual memory usage. usually around 1.4 to 1.6gb. this is especially true for things like rendering. the reason is that many applications require large areas of contiguous memory address. after youve been working a while, say, rendered a few frames or so, memory becomes very fragmented and windows can no longer allocate the areas your app needs. hence the crash. this limit gets pushed to about 2.2-2.4gb when you anable the /3gb switch. some applications, like digital fusion for example, can push memory usage much much closer to the theoretical limit.

on windows xp 64, a 32 bit app can use much much closer to a full 2gb, because there is far less fragmentation issues, as well, a properly coded application (3ds max for example) can use a full 4gb of virtual memory.

hope that clears alot of this up. i "think" i got that all right :)
later

[XanderFX]

Here is my boot.ini file utilizing 2.7GB of RAM


timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional[b]/3GB" /3GB /USERVA=2700
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /NoExecute=OptIn

copy paste your existing start up line and then add the words in bold to activate the switch. The USERVA=2700 is where you specify the maximum amount of RAM you would like to make available to apps in this case 2.7GB. You also need to have SP2 installed for this to work because it seems this option is not available on earlier service packs.

My personal experience.

Workstation Specs:

P4 3GHz HT
ATI FireGL X1 256p
3GB of PC3200 RAM
360 GB SATA RAID 0

Maya is more responsive and able to handle larger scenes with textures turned on, which I was not able to do before.

After Effects takes advantage of 2.7 GB of RAM. Able to RAM preview more than before.

Multitasking seems more responsive. Having Photoshop, Maya, and AE open and jumping between the 3

Good Luck

[DorisDay]

Hey thanks for the info, it's exactly what I needed.

I'll post to let folk know the results, probably a format...:twisted:

[ihavenofish]

i dont think the window provides the /3gb option...


the boot.ini should be in your base c: drive. edit with notepad. just back it up first and dont remove any original lines... only add a new one. incase it all goes bad.

[DorisDay]

Am I being extremely thick???

Where do you edit this text, I can see what I need to change in the system configuration utility window, but I can't access the text to edit it from there, I've done a search for various things but nothing...:shrug:

[itsallgoode9]

Thats being a bit pessamistic, most people will work with a gig of ram in any 3d app with no problems.

If you're doing texture work in photoshop while you have a 3d app, which I believe most people do, you will more than likely jump over 1 gig. If i'm working in a high res PSD with more than a couple layer, and I have maya open i'm usually using up my whole 1.5 gig of ram. Then if i'm rendering with mental ray it will jump up to 2.5 gigs while it's computeing the photons. I honestly would say it's not all that uncommon to use up a gig of ram for 3d.

[XanderFX]

to edit the boot.ini file right click on My Copmputer click on the advanced tab then click the settings button in startup and recovery and then there will be an edit button which opens the boot.ini file in notepad make your edits save and then be sure that time to display list of OS is checked and you have at least 15 seconds to select which OS you want in case your 3GB version doesn't load. Hit OK and restart and then you should get a dual boot OS selection screen during startup prior to the Windows XP logo showing up

[DorisDay]

Thank you... :thumbsup:

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