Linked by Thom Holwerda on Thu 26th Aug 2010 23:24 UTC
IBM At the Hot Chips 2010 conference, IBM announced their upcoming z196 CPU, which is really, really fast. How fast? Fastest chip in the world fast. Intended for Z-series mainframe computers, the Z196 has a clock speed of 5.2GHz. Measuring just 512 square millimeters, the Z196 is fabricated on 45nm PD SOI technology, and on its surface contains almost one and a half billion transistors. My... Processor is bigger than yours.
Thread beginning with comment 438559
To view parent comment, click here.
To read all comments associated with this story, please click here.
gilboa
Member since:
2005-07-06

A 16 MB of L1 would be idiotic, since it could actually make things like context switches very costly with so much local data to flush in/out.


Actually, the biggest issue with large L1 is not flush-on-context switch.
The bigger the cache the bigger the index tables (assuming that they are not using direct mapped cache), which in turn, increases the latency.
As a result, L1 caches tend to small and extremely fast, with bigger and slower down the pipeline until you reach the main relatively slow main memory.

- Gilboa

Reply Parent Score: 2

tylerdurden Member since:
2009-03-17

You are correct, I was just giving an example as to why really large L1 caches are not only useless but become problematic, touching on the fact that these cores are used in SMT in which case context in the L1s actually has an effect.

Reply Parent Score: 2

gilboa Member since:
2005-07-06

Oh, OK, I didn't notice the part about SMT.

- Gilboa

Reply Parent Score: 2