[OT] virtual memory

narf poit chez BOOM · #1 July 31st, 2003, 06:22 AM

i've got a new hard drive. should i put virtual memory on it, to?

Jack Simth · #2 July 31st, 2003, 06:38 AM

You usually want to put virtual memory on the drive with the most free space. If the new drive has more free space, go for it.

Slick · #3 July 31st, 2003, 07:32 AM

I think you should put your vm on the fastest drive. 99% of the time, the slowest and most limiting component on a computer is the harddrive. Speed it up, access it less, or access a faster one and you have a faster system.

JM $0.02

Slick.

Ruatha · #4 July 31st, 2003, 07:52 AM

If you have enough RAM you can try to disable virtual memory altogether.
If you get out of memory errors or warnings you can enable it.

If you can work without virtual memory it is prefarable, as it will speed up the computer some.
If you must use VM try to set it to a fixed size, the scaling of it up and down also takes some time, and if it is a fixed size you can do a boot defrag on it, if it's dynamic it will fragmantize.

[ July 31, 2003, 06:54: Message edited by: Ruatha ]

Thermodyne · #5 July 31st, 2003, 09:30 PM

The virtual memory should be fixed in size, do not let the page file alter its size dynamically. This causes it to be fragmented all over the partition.

If you have a second drive on a second controller, moving the page file to that drive will speed performance a little. It lets the system page at the same time that the system is accessing data on the system drive. Well, almost at the same time

Moving it to your SCSI stripe volume could be interesting :0

With a gig of memory, a large page file will slow the system down. Above a gig, the memory addressing load will start to slow system performance, and windows has a way of grabbing every bite of ram that it can latch onto.

As a rule, the page file should be 1.5 times the size of the installed ram. But I never found any reason for this. Big page files take longer to access, so IMHO keep it small.

No page file can cause problems. Some apps are written to use the page file for some data. This was done to free up system ram back in the day, but it still populates some code. Seti is an app that pages by default. IMHO 128megs is a ball park lower limit.

All things ram are done in 32�s, 32-64-128-256-512-1024. Try to work the page file size in the same increments. It eases the addressing load on the CPU.

Ruatha · #6 August 1st, 2003, 08:20 AM

Quote:

Originally posted by Thermodyne:

No page file can cause problems. Some apps are written to use the page file for some data. This was done to free up system ram back in the day, but it still populates some code. Seti is an app that pages by default. IMHO 128megs is a ball park lower limit.

Still, if you don't use proggies that needs VM it's better to have none, as it then won't access the HD all the time.

Quote:

All things ram are done in 32�s, 32-64-128-256-512-1024. Try to work the page file size in the same increments. It eases the addressing load on the CPU.

This I seriously question!
What should be the reason for the CPU to have "easier adress load" with 33554432 Bytes (32M) or 32M-some (ex 30M)?
Every adress between the 24 and the 32M range uses the same adress length (actually, above 16M it uses the same registers IIRC).
And a modern PC is made for large adress lenghts, so it should make no significant change to the internal workload for the computer what size the page file is, the only difference is in the drive handling. (And as I've stated far below in fragmantazion, aka also drive issues)
Right?
Enlighten me.

[ August 01, 2003, 07:24: Message edited by: Ruatha ]