PowerPC G4 Plus breaks 1GHz barrier
Trouble is, yields suck, apparently
Motorola has begun sampling its next-generation PowerPC 74xx processor, aka the G4e or G4 Plus.
According to a "trusted" Motorola source, cited by MacOS Rumors, the company's test runs are producing chips that run over 500MHz, with some even reaching 1050MHz, breaking the gigahertz barrier. Motorola's goal with the G4 Plus is to get the PowerPC 74xx chip to 700MHz and beyond, or so the company said at last autumn's Microprocessor Forum, at which the new chip was unveiled.
Motorola is expected to go into greater detail about the G4 Plus and its successors at this year's Forum, which will take place in October in San Jose. The Forum is usually used to announce processors still some way from completion, so Mac users waiting for single-CPU gigahertz Macs may not see such a machine for some time.
Motorola's main problem at the moment appears to be yield. According to the source, fewer than ten per cent of the chips produced on each silicon wafer operate at 500MHz or above. That sounds bad, but now Motorola has got the chip working, it can focus on improving its production. Besides, it's a given in the semiconductor industry that chips - particularly new, built-from-the-ground-up microprocessors, begin their lives with very low yields.
Indeed, yields are arguably more of an issue for the computer manufacturer than the chip supplier, since yield governs the cost of the part, which is why Intel, for example, didn't do too badly out of the original Pentium despite abysmal yields. Motorola may soon be able to punch out sufficient G4 Plus chips to keep Apple happy, but don't expect the boxes to be cheap.
On this basis, a possible timeframe would see Apple announce a G4 Plus early next year - MacWorld Expo San Francisco? - with a ship date a month or so down the line and volume production by Q2 2001. Fingers crossed, anyway... ®
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