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Comment by senfiaj

8 hours ago

Back in 2004 my PC RAM was 256. My relative's laptop had 128. That's crazy when a modern CPU cache can theoretically host an OS (or even multiple OSes) from early 2000s.

The Power4 MCM had 128 MB cache in 2001. The G4 TiBook sold the same year came with 128 MB of system RAM base, and OS X supported 64 MB configurations for a few years after this.

The RAM prices are so high and the storage is also getting more expensive every day, so we're forced to fit everything inside the CPU cache as a solution! /s

  • It would be interesting if it allowed to use the cache as ram and could boot without any sticks on the motherboard.

    • Several processors support this by effectively locking cache lines. At the low end, it allows a handful of fast interrupt routines without dedicated TCM. At the high end, it allows boot ROMs to negotiate DRAM links in software, avoiding both the catch 22 and complex hardware negotiation.

    • Instead of a cache you could put down an SRAM buffer, it would be more efficient than a cache and just as fast. And addressable. Interesting idea.