Is the ICS ModXStream Pro 500 enough for CrossFire 4770?

According to a technical review two ASUS Radeon 4770 video cards in Crossfire mode maxed out at 355 watts. Here's the link to the power consumption page:

http://www.legionhardware.com/document.php?id=828&p=8

According to a different review one Radeon 4770 video card used 239 watts during a Crysis gaming session. Here's the link to that power consumption page:

http://www.bit-tech.net/hardware/graphics/2009/04/28/am...

We have another technical review where a single 4770 was used with an overclocked quad core. The power measurement was done at the wall outlet and included all components inside the pc case. At full load the pc drew 369 watts. Here's a link to the power consumption page:

http://www.pureoverclock.com/review.php?id=744&page=17

Finally we have one more review where a single 4770 was used during a game of S.T.A.L.K.E.R. - Clear Sky at 1280x1024 resolution with high image quality. The total power consumption for all components inside the pc case case was 245 watts. Here's the link:

http://www.legitreviews.com/article/963/10/

I'm scratching my head over this one due to the different methods used to measure power consumption. It's a little more difficult to interpret the results.