salut,
c'est quoi ton alim ?
Power Consumption Results: The ATI Radeon HD 4870 X2 by itself isn't that bad, but when run in CrossFireX you better keep an eye on things. Our Corsair HX620W power supply is rated for operation at 620W, but was pulling 791W when trying to run CrossFireX with the Radeon HD 4870 X2's. Certain benchmarks like 3DMark Vantage were corrupted as the power supply just couldn't handle the load. A quick switch over to a Cooler Master 1000W ESA power supply and the benchmarking went on without a problem. With the new power supply running more efficiently the peak power consumption on the Radeon HD 4870 X2 in CrossFireX was 755W. This is nearly 7 Amps of power draw, so if you have an older house with a number of electronics on a 15 Amp service you might be in trouble. Also it was interesting to see how different games draw different amounts of power. The CrossFireX platform didn't scale in Crysis, but did in Call of Duty 4 as you can see from both the benchmarks and the chart above. http://www.legitreviews.com/article/766/11/
sinon, tu as testé les deux cartes séparément, et tu les as testés en les inversant en crossfire ?
et les deux pluggés mais sans crossfire, le système est stable ?
t'as lu le manuel de la mobo ? des fois il y a une astuce qui peut échapper.
ps : à noter, que je ne sais pas si ça vaut la peine de stabiliser le montage. en lisant deux reviews de 2x4870x2 , sur 10 jeux il y en a 8 ou 9 dont les perfs sont équivalentes à une seule carte. (cod4 et dmc4 étant ceux qui profitent le plus)