swap file on RAM drive - good idea?

[B P]

I've been running my Dell Latitude C400 with 256MB RAM for
a while now. Reasonably happy with system performance.

I just adde 512MB of RAM with the idea to put my Windows
swap file on a RAM drive (RAM drive is currently 450MB -
remainder is available system RAM). The RAM drive is set
up just fine, but all the guidelines I can find for
setting the size of the swap file suggest it should be
larger than total RAM. Obviously if the swap file is
resident on a RAM drive, it cannot be larger than
available RAM.

How big should my swap file be?

 

[Dan Seur]

AFAIK a RAM drive is not much good in a paging sys where the pagefile is
properly set and the swap algorithm includes recent-use info, and AFAIK
they all have for decades. Could be wrong in specific cases, I guess.

Pagefile size/placement in W2k is a matter of opinion. Try around 3x
RAMsize and fiddle up & down; set MINsize=MAXsize; place pagefile on
most-freq-used partition on least-freq-used HDD on least-freq-used
controller. Fastest available HDD also enters into this judgment. For a
given sys the real answer comes from experimenting.

Pagefile on RAM drive intuitively seems vulnerable to double swaps.

 

[Rob Stow]

Pagefile on RAM drive intuitively seems vulnerable to double swaps.

Depends on what you use to create the RAM disk.
If, for example, you use the RAMdisk software from www.superspeed.com
then nothing on the RAM disk gets swapped.

I have used their RAMdisk with both NT and W2K, but I prefer
their SuperSpeed instead. SuperSpeed lets you have a RAMdisk
for speed that is also mirrored to a hard disk for data
protection in the event of something like a hard drive failure.
In many cases their SuperCache software is - for me at least -
a better choice than either SuperSpeed or RAMdisk.

I *have* tested RAMdisk as a storage place for the page file.
I find the performance gain to be small - especially compared
to the gain you could get by using that same RAM in other
ways.

I suggest you take a look at their website and read up on
there three main products: SuperSpeed, SuperCache, and RAMdisk.
I also suggest you take a peek at this article about using
SuperCache with the page file: http://www.superspeed.com/paging.html
That article is a little out of date - it goes back to when
128 MB was considered a lot of RAM for a non-server - but it
applies just as well to systems with 2 GB as it does too systems
with only 128 MB.

I have SuperCache at one of the places where I use W2K. That system
has 2 GB of RAM. Persuant to the article mentioned above, I set
the page file to 4 GB on a dedicated partition and then set SuperCache
to allocate 256 MB for caching that partition. Doing this gives me
just as much of a speed boost using 256 MB of RAM for a cache as I got
when I tried using a 1 GB page file on a 1 GB RAMdisk.

I would also be interested in feedback from anyone who has used any of
the www.superspeed.com products with XP.

 

[Dan Seur]

Great info - thanx, Rob.

Depends on what you use to create the RAM disk.
If, for example, you use the RAMdisk software from www.superspeed.com
then nothing on the RAM disk gets swapped.

I have used their RAMdisk with both NT and W2K, but I prefer
their SuperSpeed instead. SuperSpeed lets you have a RAMdisk
for speed that is also mirrored to a hard disk for data
protection in the event of something like a hard drive failure.
In many cases their SuperCache software is - for me at least -
a better choice than either SuperSpeed or RAMdisk.

I *have* tested RAMdisk as a storage place for the page file.
I find the performance gain to be small - especially compared
to the gain you could get by using that same RAM in other
ways.

I suggest you take a look at their website and read up on
there three main products: SuperSpeed, SuperCache, and RAMdisk.
I also suggest you take a peek at this article about using
SuperCache with the page file: http://www.superspeed.com/paging.html
That article is a little out of date - it goes back to when
128 MB was considered a lot of RAM for a non-server - but it
applies just as well to systems with 2 GB as it does too systems
with only 128 MB.

I have SuperCache at one of the places where I use W2K. That system
has 2 GB of RAM. Persuant to the article mentioned above, I set
the page file to 4 GB on a dedicated partition and then set SuperCache
to allocate 256 MB for caching that partition. Doing this gives me
just as much of a speed boost using 256 MB of RAM for a cache as I got
when I tried using a 1 GB page file on a 1 GB RAMdisk.

I would also be interested in feedback from anyone who has used any of
the www.superspeed.com products with XP.