4 ms·

The other thing I'm interested to learn -- did the evolution of RAM proceed as kind of a "hand me down" technology from the CPU industry and basically tied to t

The other thing I'm interested to learn -- did the evolution of RAM proceed as kind of a "hand me down" technology from the CPU industry and basically tied to that? In that, I imagine memory is just about cramming more and more into the same space, and doesn't require the same complexity of innovation as CPUs (maybe some new developments in addressing, bus, or whatever) -- mostly just increasing the density and getting more storage locations in the same area? Or are there very interesting stories about RAM too? I do know some of the advances in hard disk magnetic breakthroughs, but silicon memory, not so much.

kens 6y ago
Don't get me started on RAM. There's a whole lot of history there especially core memory. But to answer your specific question, Intel started off as a RAM company and their first product was a 64-bit (in total) RAM chip [1]. Processors were a sideline compared to the RAM market until the mid-1980s when Intel bailed out of DRAM as Japan took over. When Intel created a new chip process back then (HMOS through HMOS-III), they would first build a static RAM chip with the process. Once that worked, they would then use the process for microprocessors like the 8086. [1] http://www.righto.com/2017/07/inside-intels-first-product-3101-ram.html http://www.righto.com/2017/07/inside-intels-first-product-31...
- rasz 6y ago
  If you study to become MBA Intel memory business is its own separate case study https://www.gsb.stanford.edu/faculty-research/case-studies/intel-corporation-dram-decision https://www.gsb.stanford.edu/faculty-research/case-studies/i...
- peter303 6y ago
  Memory circuits were relatively easy entry points for low cost Asian countries. So about 90% of that business migrated out of US and Europe to Asia.
rasz 6y ago
DRAM requires incompatible fab steps to CMOS (probably also NMOS). This is one of the reasons you dont see much DRAM in CPUs or compute on ram.
- jecel 6y ago
  The first few generations of DRAM used the same fabs as logic circuits. But the capacitor for each bit took proportionally a larger and larger area with newer processes. So they came up with the idea of making the capacitors vertical instead of horizontal (essentially a deep well into the silicon with the capacitor actually being the walls of the well) and the steps became different. You can still make DRAMs with the logic process (normally for the last level caches) but it will be less efficient than the dedicated process.
- dreamcompiler 6y ago
  Another reason is that DRAM is a lot slower than SRAM, and you want registers and cache to be as fast as possible.
retrac 6y ago
RAM came first. Even in the late 1960s, semiconductor SRAM was faster than core memory. Far more expensive, but faster. That created a market segment for caches and registers for high-end mainframes. DRAM quickly followed, and the 1103 DRAM of 1970, holding a total of 1024 bits, was Intel's first breakthrough product: https://en.wikipedia.org/wiki/Intel_1103 https://en.wikipedia.org/wiki/Intel_1103 DRAM and SRAM were already a multimillion dollar market by the time the first microprocessors came along a few years later.

kens 6y ago

Don't get me started on RAM. There's a whole lot of history there especially core memory. But to answer your specific question, Intel started off as a RAM company and their first product was a 64-bit (in total) RAM chip [1]. Processors were a sideline compared to the RAM market until the mid-1980s when Intel bailed out of DRAM as Japan took over. When Intel created a new chip process back then (HMOS through HMOS-III), they would first build a static RAM chip with the process. Once that worked, they would then use the process for microprocessors like the 8086. [1] http://www.righto.com/2017/07/inside-intels-first-product-3101-ram.html http://www.righto.com/2017/07/inside-intels-first-product-31...

rasz 6y ago
If you study to become MBA Intel memory business is its own separate case study https://www.gsb.stanford.edu/faculty-research/case-studies/intel-corporation-dram-decision https://www.gsb.stanford.edu/faculty-research/case-studies/i...
peter303 6y ago
Memory circuits were relatively easy entry points for low cost Asian countries. So about 90% of that business migrated out of US and Europe to Asia.

rasz 6y ago

DRAM requires incompatible fab steps to CMOS (probably also NMOS). This is one of the reasons you dont see much DRAM in CPUs or compute on ram.

jecel 6y ago
The first few generations of DRAM used the same fabs as logic circuits. But the capacitor for each bit took proportionally a larger and larger area with newer processes. So they came up with the idea of making the capacitors vertical instead of horizontal (essentially a deep well into the silicon with the capacitor actually being the walls of the well) and the steps became different. You can still make DRAMs with the logic process (normally for the last level caches) but it will be less efficient than the dedicated process.
dreamcompiler 6y ago
Another reason is that DRAM is a lot slower than SRAM, and you want registers and cache to be as fast as possible.

retrac 6y ago

RAM came first. Even in the late 1960s, semiconductor SRAM was faster than core memory. Far more expensive, but faster. That created a market segment for caches and registers for high-end mainframes. DRAM quickly followed, and the 1103 DRAM of 1970, holding a total of 1024 bits, was Intel's first breakthrough product: https://en.wikipedia.org/wiki/Intel_1103 https://en.wikipedia.org/wiki/Intel_1103 DRAM and SRAM were already a multimillion dollar market by the time the first microprocessors came along a few years later.