Dual Channel & Virtual Memory

Necrosis · Apr 18, 2003, 07:51 PM

Okay I feel like an idiot for asking this but I need some advice.

I just installed my second stick of ram and I'm wondering what should I set the virtual memory to?

Currently I have it set at what XP setup on install w/ 512. Does anyone recommend any other settings? The reason I'm asking this is because normally with a regular board I would use the standard formula to calculate virtual memory. However, since I'm running a dual channel board and both sticks of ram work independant of one another I'm confused.

Thanks in advance!

Vampyromaniac · Apr 19, 2003, 02:18 AM

I think it's the same, dude.

Namely, that it should be based only on the quantity of RAM you have., nothing else

shuki · Apr 19, 2003, 02:33 AM

I have 2x256 dual channel and set mine according to usual rule at fixed rate of 768.... dunno though if thats "optimal" or not hehe...

tragic · Apr 19, 2003, 02:56 AM

There are so many different opinions on this one it can get confusing.

I notice you have 2 hard drives, and what i did was to put my pagefile on the second hardrive. Now the size is debatable. I have 512 dual channel memory and i have set mine as 1024 min and max on a separate partiton on the 2nd hard drive.

For now, this seems to work perfectly on my rig. Hope this helps

Necrosis · Apr 19, 2003, 05:19 AM

You all are going to laugh at me but I honestly thought when you ran dual channel that windows would only see 512 of memory. From how I understood how it worked was similar to a 0 stripping raid array. I was surprised to learn the total ram amount is actually seen. Go ahead and laugh it up!

Dom · Apr 19, 2003, 05:57 AM

Mines at 768.

Matth · Apr 19, 2003, 09:07 AM

Dual channel make no difference to the amount of RAM available - it's just that providing two 64 bit datapaths can increase the speed - although iot eventually has to feed through a SINGLE 64 bit datapath to the CPU, at no greater speed (unlike Intel solutions - a 533FSB with 2x 266 DDR).

For virtual memory - it's controversial....

The "X" times real memory can lead to massive swapfiles, mostly unused, as if you add RAM but do not increase the workload, it should need LESS virtual, not more.
And if RAM is short, and the degree of overcommitment allowed is high enough - you can run (slowly) a large workload by using excessive swapfile.

My favourite method.....
OBSERVE ON AUTOMATIC!
Load a "normal" workload of all the programs you would run together, plus a couple of "occasionals". If you edit CD-size WAV files, then load one in your editor, and do some actions as well.

Set the minimum a bit higher than you observed, and the maximum to no maximum, or to a suitably large figure according to RAM and available disk space - if something goes really wild, it may be better that it runs out of virtual memory, than allocates the entire disk space as swapfile!