The Antares PowerPC 970MP is apparently a true dual-core implementation of the PowerPC, not two Altair PowerPC 970FX processors jammed together in a single chip package and sharing a single socket with some SMP electronics tossed in to make them share the CPU bus.
The Antares chip will scale from 1.4 GHz to 2.5 GHz, and depending on the overhead of using the dual-core chip inside one socket, should deliver just under twice the performance for equivalent clock speed compared to single-core PowerPC 970FX chips (also known as G5 processors by Apple Computer).
The reason that the performance will double is that each core in the Antares chip has a dedicated 1 MB L2 cache, compared to the 512 KB L2 caches in the Altair 970FX chips. Neither the 970MP nor the 970FX support L3 caches. The original GigaProcessor Ultra Lite PowerPC 970, the 970FX, and the 970MP all have 32 KB of L1 data cache and 64 KB of L1 instruction cache per core.
In addition to the dual-core Antares chip, IBM also announced kickers to the 970FX chips that offer lower power consumption and heat dissipation compared to the existing chips.
The 970FX chips span up to 2.7 GHz clock speeds, but they generate too much heat to be used in a laptop–which is one of the reasons that Apple is dumping PowerPC in favor of X64 chips from Intel Corp. A new 1.4 GHz 970FX chip has an operating power of only 13 watts under normal workloads, according to IBM, and a 1.6 GHz version of the rev on the 970FX consumes only 16 watts.
Apple Computer will presumably get these new PowerPC 970FX and 970MP processors and drop them into its Power Mac desktop and Xserve server lines as soon as possible. IBM did not mention the A word at the Power.org forum meeting in Japan, and nor did it say when it would make the chips available in its own JS20 BladeCenter blade servers.
Why IBM doesn’t have its own AIX and Linux workstations based on these PowerPC 970 chips is a bit of a mystery. But then again, so are many things that IT vendors do and choose not to do.
