Apple's Power Mac G4, touted as the first personal computer to deliver supercomputer-level performance, arrived in Hong Kong last week.

But it won't be allowed to cross the border to China without a licence, due to US government national security restrictions on the export of high-speed machines.

Under US regulations, the Mainland, together with Israel, Russia, Pakistan and 45 other countries, belongs to the so-called Tier III category, meaning that computers performing at over 2,000 MTOPS (millions of theoretical operations per second) are prohibited from being exported to those countries without a license from the US government.

The newly-introduced 450MHz Power Mac G4 has a processing power of 2,775 MTOPS and therefore will not be sold on the Mainland, confirmed Tony Li, Apple's Hong Kong-based marketing director.

As a means of preventing customers from shipping the machine to the Mainland by mistake, the G4 carton is being labeled with the following warning: "The G4 computer in this box is for use in Special Administrative Region of Hong Kong only. Export to the People's Republic of China is prohibited by law."

Li noted, however, that it is legal for subsidiaries or branch offices of Mainland companies located in Hong Kong to purchase the G4 for use in the SAR. And he indicated that whether the machine is ultimately shipped to the Mainland is not Apple's problem. "This depends on the watchful eyes of the Customs and Excise Department," he said.

Li maintains that it is unlikely that the G4 will make it into the Mainland via gray market channels. "Since the PRC government's large-scale crackdown on smuggling at the end of last year, a great majority, if not all, machines enter the Mainland market through legal channels," he said. "If that were not the case, we'd see unstable pricing since those smuggled in don't need to pay duties and therefore can be sold at a much cheaper price. So far, we haven't noticed any such situation," he said, referring to other Apple machines.

If a G4 does make its way to the Mainland, Apple will be able to refer to the serial number of the machine to trace the reseller, and will take appropriate action as necessary, Li said.

Li declined to quantify the revenue hit Apple will be taking by not being able to sell the G4 on the Mainland. He stressed that Mainland customers will continue to have access to Apple products since the G3 line will continue to be available.