4 ms·

Are you sure? I was just going off a quick search of Amazon, where 1 GB of ram cost ~30$, 1 TB of disk cost ~50$, and a CPU with ~1MB of L2 cache cost ~200$. Ba

Are you sure? I was just going off a quick search of Amazon, where 1 GB of ram cost ~30$, 1 TB of disk cost ~50$, and a CPU with ~1MB of L2 cache cost ~200$. Based on that I actually thought 100x was a comfortable underestimate, not an overestimate.

dcow 6y ago
CPU cost is not dominated by the cache size is the problem, I think.
- robocat 6y ago
  But I think that cache is roughly 50% of marginal production cost of the silicon chip die by mm2. https://cdn.wccftech.com/wp-content/uploads/2020/11/AMD-Ryzen-5000-Zen-3-Desktop-CPU_Vermeer_Die-Shot_1-scaled.jpg https://cdn.wccftech.com/wp-content/uploads/2020/11/AMD-Ryze... https://images.anandtech.com/doci/16214/Zen3_arch_19.jpg https://images.anandtech.com/doci/16214/Zen3_arch_19.jpg
  - thesz 6y ago
    Cache is not memory, it is more complex - LRU and all that, often with several access ports (quadratic space dependence). SRAM is memory that is on-die and it is much cheaper.
Dylan16807 6y ago
https://en.wikipedia.org/wiki/EDRAM https://en.wikipedia.org/wiki/EDRAM If the price/density difference was anywhere near that much you'd see a lot more chips with fat onboard DRAM caches.
thesz 6y ago
Why don't you compare 1TB of DRAM with 1TB of hard disk? Also, please consider bandwidth here. 1TB of RAM can max at ten times the bandwidth of 1TB SATA hard disk drive, if not more. The difference in price is 80-fold, but if you factor in bandwidth requirements, the price difference drops to lower levels (10 drives, more SATA or specialized controllers, etc).