Is Superfetch adjustable...?

[JustaGeek]

I posted this question in the "Superfetch" thread, but it seems to have gone unnoticed.


Is Superfetch adjustable...?

If I add more RAM to the system (I have just replaced my 2x512MB with 2x2GB, for a total of 6GB of RAM), will the superfetch automatically adjust to more physical memory, or will it have to be "reset" (turned off/on...?)

Someone on the Xtreme Systems forums said that if you install Vista with 2GB of RAM, and then add more memory, the Superfetch will still "think" that you have only 2GB of RAM, since that's the amount of memory during installation.

http://www.xtremesystems.org/f...howthread.php?t=182087
"zanzabar: it depends on your motherboard and instal disk version i didnt have a problem with 4GB, if u start with less memory and add more in then it wont use the full 35-50%for supper fetch so i would make sure that u had it all installed"

Is this false?


I see that my computer now uses about 25% of RAM on idle. Should it use more...?

Could it use more...? (to support the philosophy that empty RAM is "wasted RAM".)

Is it normal that my 6GB machine uses "only" 1.5GB on idle...?

TIA

 

[Rubycon]

Isn't it based on software useage patterns? Seems to me if the pattern of programs you regularly use does not change then the memory usage for SF will not change as well. If you open a LOT of BIG programs all the time you will find that they do open faster later on. On successive bootups there will be more disk activity while these get loaded in ram if I understand this correctly - prefetch like XP uses - helps reduce that time after a while too. There could be registry keys to change settings but this is probably best left to its own devices.

 

[JustaGeek]

That is how I understand this, and I have always thought that it works by itself, on "cruise control" so to speak.

But a statement has been made about the maximum amount of RAM apportioned to it during installation (see link above), and it makes me wonder if that is the case.

I don't mind having 3GB of RAM being used on idle, and think the Superfetch concept is great - until we come with storage devices matching the speeds of memory.

So... is it going to use more memory as it deems necessary, or it has a hard maximum limit imposed during installation with only 3GB of RAM...?

 

[nerp]

I believe that guy is mistaken.

The best way to find out is look at your resource monitor and watch the "cached" memory climb. It should basically fill up your entire block of RAM. If it doesn't, investigate. But I can almost promise you it will.

 

[Pabster]

False.

Just as Vista will adjust to the presence or absence of ReadyBoost or ReadyDrive, so too does SuperFetch adjust.

 

[JustaGeek]

That's what I thought. It would not make sense otherwise - it is a fully automated process afterall.

Thanks guys!

 

[BD2003]

It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

 

[JustaGeek]

Originally posted by: BD2003
It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

Can you elaborate...?

Mine uses ~1.5GB on idle.

What do you mean "all"?

 

[ViRGE]

Originally posted by: JustaGeek

Originally posted by: BD2003
It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

Can you elaborate...?

Mine uses ~1.5GB on idle.

What do you mean "all"?

He means all. All RAM not currently in use by active applications is put in use by SuperFetch.

 

[Pabster]

Originally posted by: BD2003
It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

I can just see one of these guys faint when, seconds after boot, my 8GB of RAM is nearly completely filled by SuperFetch. 0 Free! :laugh:

We need to sticky the SuperFetch explanation along with some others like "Why Is Vista Using So Much RAM???" right to the top of the forum.

 

[JustaGeek]

Originally posted by: ViRGE

Originally posted by: JustaGeek

Originally posted by: BD2003
It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

Can you elaborate...?

Mine uses ~1.5GB on idle.

What do you mean "all"?

He means all. All RAM not currently in use by active applications is put in use by SuperFetch.

I have a "technical mind", and to me 2 + 2 = 4. When you say all, you mean that Superfetch "controls" all the RAM installed, but fills it up as necessary...?

Another words, even if at the moment only 1.5GB of my RAM is being used, Superfetch "knows" that there is still 4.5GB available, and it will use it when the "demand" for fast access increases, correct...?

And how can you positively say "all"? Is this the main purpose and the "architecture" of the Superfetch...? There is no superimposed limit, like 50% of all the physical memory installed, right...?

 

[ViRGE]

Originally posted by: JustaGeek

Originally posted by: ViRGE

Originally posted by: JustaGeek

Originally posted by: BD2003
It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

Can you elaborate...?

Mine uses ~1.5GB on idle.

What do you mean "all"?

He means all. All RAM not currently in use by active applications is put in use by SuperFetch.

I have a "technical mind", and to me 2 + 2 = 4. When you say all, you mean that Superfetch "controls" all the RAM installed, but fills it up as necessary...?

Another words, even if at the moment only 1.5GB of my RAM is being used, Superfetch "knows" that there is still 4.5GB available, and it will use it when the "demand" for fast access increases, correct...?

And how can you positively say "all"? Is this the main purpose and the "architecture" of the Superfetch...? There is no superimposed limit, like 50% of all the physical memory installed, right...?

There is no superimposed limit, SuperFetch will use every bit of RAM not currently in use by other applications, and release it as applications need it.

 

[JustaGeek]

Now I'm clear.

Thanks, Virge! :thumbsup:

 

[BD2003]

Originally posted by: ViRGE

Originally posted by: JustaGeek

Originally posted by: ViRGE

Originally posted by: JustaGeek

Originally posted by: BD2003
It uses as much as is available. Ive upgraded from 1GB -> 2GB -> 4GB on the same machine, and it uses it all.

Can you elaborate...?

Mine uses ~1.5GB on idle.

What do you mean "all"?

He means all. All RAM not currently in use by active applications is put in use by SuperFetch.

I have a "technical mind", and to me 2 + 2 = 4. When you say all, you mean that Superfetch "controls" all the RAM installed, but fills it up as necessary...?

Another words, even if at the moment only 1.5GB of my RAM is being used, Superfetch "knows" that there is still 4.5GB available, and it will use it when the "demand" for fast access increases, correct...?

And how can you positively say "all"? Is this the main purpose and the "architecture" of the Superfetch...? There is no superimposed limit, like 50% of all the physical memory installed, right...?

There is no superimposed limit, SuperFetch will use every bit of RAM not currently in use by other applications, and release it as applications need it.

Exactly. Keep in mind that superfetch isnt a special cache, its just an algorithm that controls the entire cache. In XP, all of your ram was being used too, it was just filled over time with all the i/o that ran through your system, useful or not. SF just manages it to make sure its useful, but in either case, the cache memory is dropped when applications need it.

 

[WelshBloke]

I'm a bit confused by this thread as I'm using vista x64 with 4GB RAM and superfetch is certainly not using all my RAM.


Right now (with firefox,IE,steam,livemail,etc etc open) I'm using 1.9 GB of memory according to task manager.

So I've got 2.1GB sitting there doing faff all!

 

[kylef]

Originally posted by: WelshBloke
I'm a bit confused by this thread as I'm using vista x64 with 4GB RAM and superfetch is certainly not using all my RAM.


Right now (with firefox,IE,steam,livemail,etc etc open) I'm using 1.9 GB of memory according to task manager.

So I've got 2.1GB sitting there doing faff all!

I don't think you're looking in the right place.

Look in the "Performance" tab of Task Manager under "Physical Memory." Your "Free" memory should be much smaller than your "Cached" memory, which I'm betting is close to the 2100 MB you thought were "free". (It would be extremely unusual, if not impossible, for your system to have 1.9 GB used, 2.1 GB free, and nothing cached...)

The system Cache manager (with the assistance of the Superfetch service) does its best to keep the system cache full of useful pages, and only a very small portion truly free (empty).

 

[WelshBloke]

Originally posted by: kylef

Originally posted by: WelshBloke
I'm a bit confused by this thread as I'm using vista x64 with 4GB RAM and superfetch is certainly not using all my RAM.


Right now (with firefox,IE,steam,livemail,etc etc open) I'm using 1.9 GB of memory according to task manager.

So I've got 2.1GB sitting there doing faff all!

I don't think you're looking in the right place.

Look in the "Performance" tab of Task Manager under "Physical Memory." Your "Free" memory should be much smaller than your "Cached" memory, which I'm betting is close to the 2100 MB you thought were "free". (It would be extremely unusual, if not impossible, for your system to have 1.9 GB used, 2.1 GB free, and nothing cached...)

The system Cache manager (with the assistance of the Superfetch service) does its best to keep the system cache full of useful pages, and only a very small portion truly free (empty).

Ahh thanks, it twas exactly as you said it would be.

I was distracted by the pretty graph