How Much Virtual Memory?
Posted 23 December 2006 - 05:33 PM
Virtual memory (paging file) is an area on the hard disk that Windows uses as if it were RAM.
I've read somewhere that virtual memory should be 1.5 times of RAM, but some deny this.
Vote for the number which is the closest to your allocated virtual memory.
Posted 23 December 2006 - 06:43 PM
Answer chosen: 1000MB
Posted 23 December 2006 - 08:54 PM
I've read that shutting off your paging file speeds up your PC because RAM is much faster than your hard drive, but when I tried it, I didn't see any noticeable difference.
Posted 24 December 2006 - 04:22 AM
Edited by comedy_guy, 24 December 2006 - 04:22 AM.
Posted 24 December 2006 - 04:54 AM
Posted 02 January 2007 - 11:12 PM
Can anyone confirm this?
If you have 1GB of RAM or better you don't really need a paging file
Posted 03 January 2007 - 03:21 AM
and if U HDD is 40GB or 80GB then 1000 could do.... but for larger disk space it is always better to have max...... those who have 120GB HDD can really give a trial for better understanding .
Posted 05 January 2007 - 12:03 AM
Whenever your computer runs short of memory, the processor looks elsewhere for available space it can use in lieu of RAM. Specifically, it looks to the paging file, which is hard drive space allocated to act as virtual memory when actual RAM is unavailable.
The default paging file initial size in Windows XP is 1.5 times the amount of installed RAM (if your PC has 256MB RAM, the paging file is 384MB). Using the paging file at its default size is generally appropriate, but if you have a lot of RAM, the paging file can occupy a good deal of hard drive space (with 512MB RAM, the paging file would be 768MB). In that case, it's OKto reduce the paging file initial size. Click Start and Control Panel and double-click System. Click Advanced, Advanced again, and Change. Change the Initial Size (MB) to one half the amount of installed RAM and click OK.
Basically the amount of virtual memory you should use will depend on how resource intensive the software you are running is.
If you have 1GB of RAM it will handle virtually all basic tasks running Windows XP without slowing down even if you shut off the paging file.
If you're a hard-core gamer, your friends would never let you live it down if you only have 1GB anyway.
Edited by tominorlando, 05 January 2007 - 12:17 AM.
Posted 05 January 2007 - 03:02 AM
In a 32-bit computer, the memory addresses are 32 bits long and stored as binary (base 2) numbers. There are approximately 4 billion possible different 32-bit binary numbers (2^32=4,294,967,296). Because of this, there is a 4GB limit for addressable memory in a 32-bit computer.
A program instruction on an Intel 386 or later CPU can address up to 4GB of memory, using its full 32 bits. Each process is assigned an address space of 4GB of virtual memory, regardless of the amount of available physical memory. Each process is isolated from the rest and has its own 4GB address space. This means that the 4GB addressability limit applies on a per-application basis, not across all applications taken together.
This is normally far more than the RAM of the machine. The amount of physical memory on the computer is not related to the amount of memory address space. If a computer has 256MB of physical memory, there is still a 4GB memory address space, and if a computer has 8GB of physical memory, there is still a 4GB memory address space.
Applications are not allowed direct access to physical memory. When an application requests more memory, Windows maps some physical memory (as long as some is available) into the process's address space.
The hardware provides for programs to operate in terms of as much as they wish of this full 4GB space as Virtual Memory, those parts of the program and data which are currently active being loaded into Physical Random Access Memory (RAM). Windows maintains several tables that keep track of all of this, and the application knows only about the virtual memory address.
The processor itself then translates (‘maps’) the virtual addresses from an instruction into the correct physical equivalents, doing this on the fly as the instruction is executed. The processor manages the mapping in terms of pages of 4KB each - a size that has implications for managing virtual memory by the system.
Why do I need page file optimization?
Optimizing your page file when you're running low on RAM is always a good idea. When all physical RAM in a computer is in use, Windows starts using the hard disk as if it were additional RAM. This is why we have a Pagefile (also called the swap file). Because RAM memory is a lot more faster than the hard disk, whenever the computer begins to use the Pagefile to relieve memory pressure, we begin to experience a drastic performance degradation.
One of the most effective things you can do to improve performance is ensure that there is enough RAM available to avoid frequent paging (swapping) of memory contents between disk and RAM.
This means that the actual limit on the memory used by all applications is the amount of RAM installed plus the maximum size of the Pagefile.
How much swap space do you need? That depends the amount of RAM you have and the programs you use. The rule of the thumb is 1.5 times the amount of system memory, unless you have too much load on your system.
Can the Virtual Memory be turned off on a really large machine?
Strictly speaking Virtual Memory is always in operation and cannot be ‘turned off’. What is meant by such wording is ‘set the system to use no page file space at all’.
This would waste a lot of the RAM. The reason is that when programs ask for an allocation of Virtual memory space, they may ask for a great deal more than they ever actually bring into use - the total may easily run to hundreds of megabytes. These addresses have to be assigned to somewhere by the system. If there is a page file available, the system can assign them to it - if there is not, they have to be assigned to RAM, locking it out from any actual use.
Posted 06 January 2007 - 08:50 AM
Posted 09 January 2007 - 08:10 PM
Posted 09 January 2007 - 09:20 PM
Posted 09 January 2007 - 09:46 PM
Myth - "Disabling the Paging File improves performance."
Reality - "You gain no performance improvement by turning off the Paging File. When certain applications start, they allocate a huge amount of memory (hundreds of megabytes typically set aside in virtual memory) even though they might not use it. If no paging file (pagefile.sys) is present, a memory-hogging application can quickly use a large chunk of RAM. Even worse, just a few such programs can bring a machine loaded with memory to a halt. Some applications (e.g., Adobe Photoshop) will display warnings on startup if no paging file is present." - Source
Posted 09 January 2007 - 09:53 PM