Best solution for virtual memory?

[Ralf Strandell]

Hi,

I'm about to build a dual-boot (Windows+Linux) system that should be capable of video editing ( 60 GB of DV waiting to be edited... ). Even browsing through the material would probably fill any swap file... even if I add a few GB of RAM, right?

Which of these solutions would provide the best performance for virtual memory?

1) Keep everything on one filesystem

- Single disk, one partition (windows), use swapfile
and
- Single disk, one partition (Linux), use swapfile

2) Split each OS & swap between two disks

- Single disk, Windows OS partition, Linux swap partition
and
- Single disk, Linux OS partition, Windows swap partition

I know that putting the OS+apps on one drive and swap on another drive makes using the swap faster. But how much? Is there any true benefit? Also, I do not know how partitioning the drive affects its speed. Note that only one partition per disk would actually be in use...

3) Disable disk-based virtual memory: disable swap or put it on ramdisk or just add a few gigabytes of RAM...

ps. Video would be on a separate drive. Now I would like to know about virtual memory speed.

[Glenn Chan]

No... most NLEs do not fill the swap file.

Look at the program you are using and what the recommended specs are.

[Rob Lohman]

I would never disable the swap file on Windows system. It is there
for a good reason, no matter how much memory you've got.

I'm wondering why you think browsing through DV material will
fill your swap file. When you brwose a file it will just browse that
file, not all. And even then this will come straight from disk through
perhaps a buffer. The file is not loaded fully in memory (perhaps
it does when there is room enough).

There should be no problems at all with DV footage at 3.6 MB/s.

Personally for a normal system I keep the swapfile on the same
partition as my OS and my programs (these days with fast
harddisks). On a server (which you are not doing) I usually have
a seperate partition for the swapfile.

[Cosmin Rotaru]

video editing does not eat that much RAM as some might think. Working with megapixels pics in photoshop (or the like) would do.

Anyway, if I would need the swap file acces to be fast, I would choose the virtual memory size the same for min and max (I won't "let windows manage...") and then defragment the C: partition.
Setting min=max would let windows create a FIXED size swap file (no dinamic resize..).
Defragmenting would place the swap file at the begining of the HDD - where the R/W rates are the best (I'm not sure but I think you need some defragmenting utility that knows how to do this).

I'd say don't bother. I have 768MB, Windows XP, Vegas 5. I never need that much memory. In fact, going from 256 to 768 - I don't remember if there was a diference... (still talking about the video editing stuff)

[Glenn Chan]

NLEs like Final Cut take a lot more memory than Vegas (Vegas is like an exception and doesn't need much RAM at all).

Again, just check the recommended specs. Or post your NLE and ask people what their experience is.

[Rob Lohman]

Cosmin: defragmentation does NOT move your swapfile (and some
other filters). There are a few specific swapfile defragmenters
available.

I have 1 GB of RAM on this machine, my swapfile is set to:

Initial size: 1536 MB (1.5x amount of RAM)
Maximum size: 3072 MB (3x amount of RAM)

The file has never gone over the min. of 1.5 GB. But it can make
more room if something really needs a lot of memory.

[Cosmin Rotaru]

"defragmentation does NOT move your swapfile"

I think SpeedDisk (Norton Utilities) does just that (if nicely asked :).

Of course, there's no need to move the swap at the begining of the drive if its size is not constant (MIN=MAX). It'll still get fragmented if windows would resize it. With 1GB RAM + 1.5GB virtual memory, I don't think it will be resized. :)
BTW: what the @%$# are you doing with that much memory?! :)

[Andre De Clercq]

It's a percistant myth that NLE's need lots of physical memory for rendering speed reasons...and indeed if at the same time people like to open and play with huge Photoshop and other memory hungry programs, maybe 1 GB and more is needed. I have 512MB physical and 750MB for paging on my OS disk. Although it's generally accepted that paging gets somewhat faster on a non OS physical disk it's not adviseable if this same disk is the disk containing the video data.

[Rob Lohman]

Cosmin: I was talking about the builtin defragmenter not a third
party. But if SpeedDisk does this it should reboot (since the file
is locked and always in use) and do this before the system gets
up and running again (this is how the Sys Internals tool does it).

Andre: most NLE's do not require huge amounts of memory
indeed (although some more than others) I could ofcourse edit
with 256 MB. However the more RAM you have the longer RAM
preview renders (=fast) you can do (with Vegas for example).

But the main reason this laptop has 1 GB of memory is that movie
work is not my main job, that's programming. So my company
bought me this laptop and the last one had 512 MB which was
really NOT enough anymore. I frequently have MS SQL Server or
Oracle running with IIS webserver, multiple development
environments and a full blown content management system and
all sorts of other little applications.

As I'm typing this I'm using 400 MB with two mail programs
running and a couple of windows to do web browsing and such
and others tools. It's not uncommon for me to be actually using
700+ MB of memory with all those tools.

Anyway it DOES make the system RUN more smoothly, that's for
sure. And with memory being ultra cheap these days there's no
real reason to not have a sufficient supply of memory. But do you
NEED it to do NLE work? No, you can get by with less.

[Andre De Clercq]

Agreed Rob

[Cosmin Rotaru]

I see. I do have SQL server runing here (at work), and the app I'm testing, and with the 512MB that I have I'm at the limit most of the time, and over it from time to time. But at home, using Vegas, I don't need that much memory...