Program that allows you to use ram as a hdd?

[Energize]

I remember someone posting this a while ago, software that allows you to use your ram as if it were a hdd, just like iram but at sata 2 speeds. So you can load programs off it much faster etc...

Seeing as it only costs £140 for 4GB of ram I thought I could make use of this when I upgrade my pc.

 

[Energize]

I leave my pc on standby anyway and I've got a ups to protect against power failures so there's no risk of data loss.

 

[Energize]

I know about them, but I'm looking for a program to let me do this.