A PC that doesn't make a sound, it remains the ultimate goal for many a hardware enthusiast. We recently review the passively cooled HTPC chassis Streacom FC-5. The Dutch company Quibus Enzo proved with its Knoll Creek Silent system that it's possible to passively cool a fairly powerful system with a Core i5 processor and Radeon HD 6770 graphics card quite effectively, as long as you use the right components. If you want to create your own completely silent desktop along the same lines, you'll need a passively cooled graphics card. There isn't a whole lot of choice in that category, but Hardware.Info tested and reviewed four of them.