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IBM Unveils Fastest Microprocessor Ever
adeelarshad82 writes "IBM revealed details of its 5.2-GHz chip, the fastest microprocessor ever announced. Costing hundreds of thousands of dollars, IBM described the z196, which will power its Z-series of mainframes. The z196 contains 1.4 billion transistors on a chip measuring 512 square millimeters fabricated on 45-nm PD SOI technology. It contains a 64KB L1 instruction cache, a 128KB L1 data cache, a 1.5MB private L2 cache per core, plus a pair of co-processors used for cryptographic operations. IBM is set to ship the chip in September."
The Z-series mainframes cost hundreds of thousands (or even over a million) dollars, not the chips. As it says in the article.
The thing is that if you have 2 (say) 1.6 GHz processors, they aren't as 'powerful' as one 3.2 GHz processor.
For one - there are overheads, certain stuff common between them, pipelines - stuff which I forgot (computer engineering related problems).
But the main thing is that not all programs are multi-threaded, and a program with a single thread can only run on one processor. So yeah, GHz are still useful. Maybe for large single-thread batch processing - which is the kind of thing a mainframe would do.
More or less. They hit two walls - fabricating chips that could run faster while retaining an acceptable yield, and dealing with the heat such chips produced.
The fastest general-sale chips were the P4s - the end of their line marked the end of the gigahertz wars, as Intel switched from ramping up the clock to ramping up the per-cycle efficiency with the Core 2 and their complete architecture overhaul. As a result a 2GHz Core 2 duo will outperform a 4GHz P4 dual-core under most conditions. Better pipeline organisation, larger caches better managed.
Clock rate is no longer the key variable in comparing processors, unless they are of the same microarchitecture.