Brian's Brain

....have been greatly exaggerated. That's the big message coming out of Steve Jobs' keynote, which just concluded (greetings from the audience, thanks to Verizon EV-DO) at MacWorld Expo. Apple and partner Intel launched two Intel CPU-based hardware lines, the iMac and MacBook Pro (the latter a replacement for the existing G4 PowerBook laptop).

I shot a few photos; apologies for the dim lighting (I've got the wimpy-flash but super-portable camera with me today) but I think they'll get the point across. The first one compares the SPECint_rate2000 and SPECfp_rate2000 benchmark results of iMacs based on PowerPC G5 and Core Duo (aka Yonah) CPUs (Jobs' big-picture claim was that the Intel-based iMac is 2-3x faster than an iMac G5). The second estimates the performance-per-watt ratings of the G4 PowerBook, a hypothetical G5 PowerBook and the Core Duo-based MacBook Pro. The third shows the SPECint_rate2000 and SPECfp_rate2000 results for the G4 PowerBook and MacBook Pro (Jobs' big-picture claim was that the MacBook Pro is 4-5x faster than PowerBook G4). For more on SPECint_rate2000 and SPECfp_rate2000, see my PowerPC benchmarking study from last summer.

Important note: here's a case where reading the fine print is important. Both benchmark foils from the keynote use the 'rate' version of SPEC, which as my article points out takes advantage of multiple CPUs, and multiple cores within a CPU, to run multiple instruction threads in parallel. So when you look at the comparisons, realize that the PowerPC G4 and G5 are both single-core CPUs whereas Core Duo is, as the name implies, a dual core CPU....which automatically benefits from a ~2x SPEC 'rate' multiplier as a result. Will real-life scenarios benefit to the same degree? If you're heavily multitasking, and/or if your application is multi-threaded, sure. Otherwise, one of the Intel CPU's core will essentially be sitting there idling. And, of course, keep in mind that SPEC is a CPU-centric benchmark; other system performance determinants such as HDD, DRAM, network bandwidth, etc are equally important in getting the full picture of any PowerPC-vs-Intel system speed differential.

17" and 20" Intel-based iMacs are shipping now, at no price premium to their PowerPC G5-based predecessors. The 15.4" (1440 x 900 pixel) widescreen MacBook Pro is now available for ordering, and will ship next month. High-level specs follow:

• The 17" (widescreen) iMac contains a 1.83 GHz Intel Core Duo CPU, ATI Radeon x1600 GPU with 128 MByte frame buffer, 802.11g and Bluetooth 2.0+EDR wireless, a 160 GByte 7200 RPM SATA HDD, and 8x SuperDrive optical drive with dual-layer support, and costs $1299.
• The 20" (also widescreen) iMac is based on a 2 GHz Intel Core Duo CPU and offers a 250 GByte 7200 RPM SATA HDD. It's otherwise spec-identical to the 17" iMac. It costs $1699.
• The MacBook Pro is 1" thick and weighs 5.6 lbs. The $1999 version contains a 1.67 GHz Core Duo CPU, 512 MBytes of DDR2-667 SDRAM, ATI Radeon x1600 GPU with 128 MByte frame buffer, 80 GByte 5400 RPM SATA HDD, SuperDrive optical drive and built-in iSight camera. The $2499 variant bumps up the CPU to 1.83 GHz, the DRAM to 1 GByte, the graphics frame buffer to 256 MBytes and the HDD to 100 GByte. Notably, the MacBook Pros also discard PC Card support in favour of ExpressCard/34.

I'll write more on the train ride home tonight, after I've had a chance to grab the documentation at the press room and wander the show floor for a bit.