4 ms·

SRAM is so stupid fun to play with. All of a sudden you don't care so much about the inefficiencies of walking linked lists or trees. When everything is "alrea

SRAM is so stupid fun to play with. All of a sudden you don't care so much about the inefficiencies of walking linked lists or trees. When everything is "already in cache", you can worry less about cache efficient algorithms! 1 cycle memory access latency is one of the reasons why tiny embedded MCUs can do things with a fraction of the MHZ of their larger counterparts. Now days of course it is all about tons of memory, tons of bandwidth, craptons of compute, and planning the flow of data ahead of time.

boringuser2 3y ago
Only within a very small domain was this ever reasonable.
- jwr 3y ago
  But that's why there's a "super" in "supercomputers"! Cray loaded a ton of static memory into their computers, then liquid-cooled the whole thing. Sure, the power requirements were through the roof, and you had a whole huge chiller system which you had to run and hope it doesn't fail. If it did fail, you really wanted to shut the machine down fast. From what I recall there was also an emergency propeller inside the back case of the Y-MP 2E, and yes propeller is a much better name for this thing than a "fan". It would delay the inevitable, although dumping those tens of kW of heat into your server room was not something you ever wanted to do. The whole point of all this was that you could do things that you couldn't with "normal" computers. That's why those were called "supercomputers". And I'm so glad that after a hiatus of about 30 years we're getting another wave of exceptional machines, which aren't just bigger PCs.
Dylan16807 3y ago
L3 cache is all SRAM but you can have pretty significant delays accessing it. Even the fastest memory cells will build up significant addressing delays as you increase in scale.
creato 3y ago
If you have a “large” SRAM that can be accessed in one cycle, that just means your processor is slow and/or consumes more energy than it should.
- com2kid 3y ago
  > If you have a “large” SRAM that can be accessed in one cycle, that just means your processor is slow and/or consumes more energy than it should. MCUs are in this category, lots of embedded stuff, including the two areas I'm familiar with: game controllers and lower spec'd wearables. Very low power usage, CPU speed around 100mhz, so not too slow. You can do plenty with 100mhz and SRAM!
  - SmoothBrain12 3y ago
    [dead]

boringuser2 3y ago

Only within a very small domain was this ever reasonable.

jwr 3y ago
But that's why there's a "super" in "supercomputers"! Cray loaded a ton of static memory into their computers, then liquid-cooled the whole thing. Sure, the power requirements were through the roof, and you had a whole huge chiller system which you had to run and hope it doesn't fail. If it did fail, you really wanted to shut the machine down fast. From what I recall there was also an emergency propeller inside the back case of the Y-MP 2E, and yes propeller is a much better name for this thing than a "fan". It would delay the inevitable, although dumping those tens of kW of heat into your server room was not something you ever wanted to do. The whole point of all this was that you could do things that you couldn't with "normal" computers. That's why those were called "supercomputers". And I'm so glad that after a hiatus of about 30 years we're getting another wave of exceptional machines, which aren't just bigger PCs.

Dylan16807 3y ago

L3 cache is all SRAM but you can have pretty significant delays accessing it. Even the fastest memory cells will build up significant addressing delays as you increase in scale.

creato 3y ago

If you have a “large” SRAM that can be accessed in one cycle, that just means your processor is slow and/or consumes more energy than it should.

com2kid 3y ago
> If you have a “large” SRAM that can be accessed in one cycle, that just means your processor is slow and/or consumes more energy than it should. MCUs are in this category, lots of embedded stuff, including the two areas I'm familiar with: game controllers and lower spec'd wearables. Very low power usage, CPU speed around 100mhz, so not too slow. You can do plenty with 100mhz and SRAM!
- SmoothBrain12 3y ago
  [dead]