Well, not always - Taiwan's ETC (Electronic Testing Center) labs sometimes comes across major brand products which don't exactly pass some of the EMI tests.

A fairly recent example is Gigabyte's GA-P35-DS3 mainboard, based on the Intel's P35 chipset, one of which may have been lying in waste, dropped on the floor of Taiwan's spanking new 300 km/h Shinkansen high speed train somewhere between Taipei and Kaohsiung...

Basically, according to the ETC tests, the mainboard slightly exceeds the allowed limit in the horizontal polarity (see screenshot) and vertical polarity CE EMI tests. The 5 dB difference isn't small, but isn't particularly alarming either. According to other tests, similar MSI and Asus boards were within the limits, but close to them.

Of course, the problem could have been with the particular sample, and may not mean anything truly serious. Or, it could mean that whole batches pump out too much radiation.

Gigabyte's competitors shouldn't open the Champagne too quickly on this, however, as it could happen to them too.

So, it's worth checking out and ensuring that, if you buy a quantity of any electronics componentry from any brand, big or small, the accompanying EMI certificates have an actual verifiable lab report attached - an occassional EMI gaffe might not affect the system functionality, but could just kill, say, a government tender bid if a picky bureaucrat is on the other side. µ