There’s OpenCL Benchmark of Radeon 4870, which show it slower than nVidia 9400M IGP (on Mac Mini, Mac Book Air, …).

Why radeon 4xxx are so slow? They lack “shared memory” that is the equivalent on a graphic card GPU of a processor cache, so every access to memory is 20X to 30X slower than access to cache (or “shared memory” in this case) and it could not compete even if it’s a 400$ graphic card!

If Radeon 4870 could not compete with GeForce 9400M, how a Radeon 4670 will? Having 4X slower memory and 3X less computing power, the Radeon 4670 will be crushed by GeForce 9400M, not talking about GeForce GT120 or even GT130 of last generation iMac!

Even high-end iMac with Radeon 4850 (0.8X slower than 4870 GPU with 2X slower memory) won’t be able to compete with entry-level iMac! It’s sad!

Anyway, what is really interesting is that old 3.06Ghz iMac is faster than new 3.06Ghz iMac on MacWorld’s new SpeedMark 6 suite. So the refurbished iMac 24″ 3.06Ghz is a real bargain

And for performance/price balance, the new entry-level 21.5″ Cor2 Duo 2×3.06Ghz equipped with GeForce 9400M seems to be unbeatable, and probably the most interesting model of the new line, except the 27″ Core i5 for power hungry

On OpenCL benchmarks that will rely on real-world OpenCL or CUDA ported applications, I wonder that old-generation equipped with GT130 or GeForce 8800 will easily beat Radeon 4670 or even 4850 cards, even if they are slower on pure games!

Alas, no USB 3.0, no eSATA, no SSD, no Firewire 3200 …

Wanna copy files from 1 external hard-drive to another? 45MB/s speed limit, my MacBook Pro with it’s eSATA ExpressCard is between 80MB/s and 90MB/s, 2X faster!

Please Apple, put an ExpressCard/34 slot into your next-generation iMac for us to be able to upgrade to eSATA, USB 3.0, 2 Firewire 800 ports, FireWire 3200, …