Hard Light Productions Forums

Off-Topic Discussion => General Discussion => Topic started by: Kie99 on December 19, 2004, 03:12:25 pm

Title: Virtual Memory?
Post by: Kie99 on December 19, 2004, 03:12:25 pm
What does it do, I know it says windows uses it as RAM but is it as good as RAM, i.e. if I had a PC with 128mb of RAM and I changed my virtual memory to 896MB would that give me the same performance as someone with 1024MB of RAM not using any virtual memory, given equal system specs apart from RAM
Title: Virtual Memory?
Post by: Sandwich on December 19, 2004, 03:21:36 pm
Nope. Virtual Memory is just using hard disk space as memory, with all the inherent slowness that comes with it.
Title: Virtual Memory?
Post by: MatthewPapa on December 19, 2004, 03:58:03 pm
It is essential to be able to run Fsopen with some options if you dont have much ram I have found. I keep at least 2000 mb win my system at all times.
Title: Virtual Memory?
Post by: Clave on December 19, 2004, 05:07:44 pm
Virtual memory is an abomination.  

Maybe when RAM was expensive and slots were few, then it could be excused, but now, when you have 8 slots with 256MB in each, or a gig in each if you have extra cash, what is the reason to continue with VM?.....
Title: Virtual Memory?
Post by: Stealth on December 19, 2004, 05:08:56 pm
... because you can.
Title: Virtual Memory?
Post by: Taristin on December 19, 2004, 05:10:30 pm
Quote
Originally posted by Clave
Virtual memory is an abomination.  

Maybe when RAM was expensive and slots were few, then it could be excused, but now, when you have 8 slots with 256MB in each, or a gig in each if you have extra cash, what is the reason to continue with VM?.....


Err... you're the only one with 8 RAM slots :p

My PC only has 3 RAM slots, and my parents have only 2...
Title: Virtual Memory?
Post by: Unknown Target on December 19, 2004, 05:26:10 pm
Mine has 3 slots of RAM and I only have 256 Megs of it :D
Title: Virtual Memory?
Post by: Taristin on December 19, 2004, 05:46:25 pm
I still have one open slot...
Title: Virtual Memory?
Post by: diamondgeezer on December 19, 2004, 06:04:05 pm
Ph34r my 1.25GB of memory

__________________
Diamond Geezer always buys PC hardware on-line
Title: Virtual Memory?
Post by: vyper on December 19, 2004, 06:17:20 pm
Virtual Memory is required because you'll never have such a thing as enough RAM - it's impossible to have enough physical memory for every possible load configuration. Example:
Your memory = 256MB. Memory load = 240MB (hell knows how) then you launch an application which adds about 120MB (say a 3D modeller) to the memory load. If you don't have any VM to put the overflow into, you get a million access violations and then a complete crash. Bye bye everything.
Title: Virtual Memory?
Post by: Kamikaze on December 19, 2004, 06:34:40 pm
Virtual memory is, in more efficient operating systems, used to keep stuff that won't be used for a while.

For example, if I'm playing a game I don't want my browser or IRC client in RAM. I want my game to get all the resources.

If I'm running a huge compile I don't want other applications wasting RAM.

This is why when you're running very resource intensive applications and then quit and switch over to other applications they seem to be stuck or very slow until the paged stuff comes back to RAM.

If you don't like the slowness you get from virtual memory you can reduce it and force the operating system to swap less. This means you'll get overall worse performance though (though GUI applications might feel a bit snappier).
Title: Virtual Memory?
Post by: Kosh on December 20, 2004, 02:21:04 am
Quote
Originally posted by Clave
Virtual memory is an abomination.  

Maybe when RAM was expensive and slots were few, then it could be excused, but now, when you have 8 slots with 256MB in each, or a gig in each if you have extra cash, what is the reason to continue with VM?.....



Because not all of us do. My laptop has 384 MB of RAM and my desktop has 256 MB. I could not play FSO without virtual memory. They won't do away with it because they need that kind of flexibility.



And a system board with 8 slots sounds quite a bit more like a high end server board to me. I've seen $150+ desktop boards that only have 4 slots. :p

Windows will only use your virtual memory when it has to as I understand it.
Title: Virtual Memory?
Post by: Clave on December 20, 2004, 07:44:34 am
It's a G5, and yeah, it does use virtual memory - I'm using the G4 at the office right now, so here are the settings for that:  (Only 4 slots)

(http://homepage.mac.com/clave/misc/mem.jpg)
Title: Virtual Memory?
Post by: Kie99 on December 20, 2004, 01:06:45 pm
SO any yes or no answers
BTW I have 40GB of VM and 512MB of RAM
Title: Virtual Memory?
Post by: aldo_14 on December 20, 2004, 01:29:59 pm
No, your performance with VM would be nowhere near as good as someone with the equivalent amount RAM.
Title: Virtual Memory?
Post by: Clave on December 20, 2004, 03:40:05 pm
Yep..

For example take EDO RAM with a 50nS access speed, and a 7,200rpm HD with 15mS access time.

Your speed differential is about 300,000:1 - basically your memory will have done 300,000 things by the time your HD has done one.

It's slow, very slow....
Title: Virtual Memory?
Post by: diamondgeezer on December 20, 2004, 04:30:37 pm
Remind me, wise man say virtual RAM should be set to same size as physical RAM yesno

__________________
Diamond Geezer is a technophile
Title: Virtual Memory?
Post by: vyper on December 20, 2004, 04:34:24 pm
Should be twice physical ram size... or something like that.
Title: Virtual Memory?
Post by: Clave on December 20, 2004, 04:51:28 pm
Just let your OS manage it, that usually works.  

Something like 'recommended settings'  ??  

I don't use Windows much....
Title: Virtual Memory?
Post by: diamondgeezer on December 20, 2004, 05:08:33 pm
Let Windows manage itself? Surely you jest...

__________________
Diamond Geezer has more RAM than you do
Title: Virtual Memory?
Post by: Martinus on December 20, 2004, 05:10:12 pm
Quote
Originally posted by diamondgeezer
Ph34r my 1.25GB of memory

[color=66ff00]My stick is bigger than your stick.
[/color]
Title: Virtual Memory?
Post by: diamondgeezer on December 20, 2004, 05:25:25 pm
:nervous:

__________________
Diamond Geezer regularly dusts his PC components
Title: Virtual Memory?
Post by: Ford Prefect on December 20, 2004, 05:26:17 pm
Clave, how much hard drive space does the G5 have? I was talking with someone who said basically that Macs don't give you enough hard disk space for the amount of money you pay.
Title: Virtual Memory?
Post by: Clave on December 20, 2004, 05:36:11 pm
Top end 160GB, bottom end 80GB....


Mine is... probably not typical, but 160GB SATA, and a 120GB SATA, erm, and a 320GB Firewire for backup...
Title: Virtual Memory?
Post by: Ford Prefect on December 20, 2004, 06:03:13 pm
Wow. Either that's a ****load of space or I've been under a rock for a while.
Title: Virtual Memory?
Post by: Kosh on December 20, 2004, 09:15:55 pm
Quote
Originally posted by Clave
Just let your OS manage it, that usually works.  

Something like 'recommended settings'  ??  

I don't use Windows much....



I usually let it manage itself. It actually seems to do it right......