As predicted by MacUser, Apple revved its professional G4 series of desktops today. And it's a dramatic speed bump. Although the new machines are G4 and not G5 based, which isn't that surprising, real and potential bandwidth improvements suggest that Apple is serious about taking on SGI's low end business with its own professional Unix workstation. The Mac is finally joins the PC world mainstream in supporting DDR-RAM, but that's in the processor cache: the motherboard takes PC133 SDRAM, as before. The most eye-catching improvement is that two of the three options debut with a whopping 2MB of DDRAM Level 3 cache. The base model is now a 800Mhz uniprocessor box, the midrange a single 933Mhz and the high-ends two 1Ghz CPUs. The low end uses ATI's Radeon, the other two models the Nvidia GeForce4 through a AGP4x interface: a first for Apple. On the negative side, all models default to the ATA-66 interface, which means the Mac lags two generations behind high-end PCs, which now feature ATA-133. That's not something that will affect professional users who most likely opt for SCSI or RAID storage, but it leaves budget-conscious pros short-changed when it comes to those peak file transfers. ATA-66 cards rolled out in June 2000.