I just read somewhere that if you use a riser (like this one: http://dx.com/p/pci-e-1x-to-16x-riser-card-extension-cable-15-5cm-length-100061) you can actually use newer cards in older mobos without a loss in hash rate. Is this true? I've only read it once and it sounds kind of bullshit.

If it is true, I can save a lot of $$$ on my mobo