5 ms·

> regular RISC platforms were riding an economy of scale I've found a fascinating page [1]. [1] https://computer.fandom.com/wiki/Instructions_per_second#Timel

by thesz 3y ago

> regular RISC platforms were riding an economy of scale I've found a fascinating page [1]. [1] https://computer.fandom.com/wiki/Instructions_per_second#Timeline_of_instructions_per_second https://computer.fandom.com/wiki/Instructions_per_second#Tim... ARM (1986) has 4 Dhrystone MIPS, and Motorola 68020 (1984, as CISC as you can get) has 4.84 Dhrystone MIPS. RISC was not riding economy of scale then, it barely existed on the periphery of the mass computing, being utilized in very expensive workstations or cheap arcade game consoles. The first significant RISC chip that made any waves was Alpha AXP 21064, when banks worldwide started to buy these in bulks. The fact that 68020 outperformed ARMv2 is what people from Syymbolics had at hand then, in 1986, writing that document.

kryptiskt 3y ago
But they weren't looking at ARM, they were looking at MIPS, which handily outperformed them at the time. ARM wasn't on their radar at all, since that was an oddball UK chip not used by any of their competitors. Symbolics competed in the very expensive workstation market, their machines cost more than most in that category, so they had to keep up the performance of MIPS R2000.
- thesz 3y ago
  MIPS (R2000) did not outdone Intel and/or Motorola at the time, those last, but not least two enjoyed all "economics of scale" of the world. MIPS was slower clock-frequency-wise than competitive offerings from Intel and/or Motorola and better pipeline design of MIPS did not add much. Complex expensive workstation like IRIS used proprietary hardware to boost I/O bandwidth and/or to have several CPUs working in parallel. It was easier for SGI to make CPUs and other hardware around them in accord and I honestly think that Symbolics was able to pull something like that.
- simne 3y ago
  As I hear, ARM at beginning was near pure educational chip, or toy for mature boys. MIPS grown on very different soil, it was from beginning pushed by business shark. Only much later, created ARM holding and they pushed ARM architecture to mass market, but even now their behavior looking strangely lazy, as for me.
simne 3y ago
This is not fair compare. Motorola and Intel that time outperforms first RISC machines, because have much better silicone level (even when logic level was not best). But game consoles are fair, as they was specialized machines, made with good silicone and with large scale production. On the same time, I'm not agree to consider 68020 as genuine CISC machine - I think it is more fair to consider it hybrid - RISC-optimized CISC (or, as it named on rumor talks - "mini on one chip"). I think, genuine CISC machines was most S/360 and some mini-machines, like Alto in which was documented feature to develop your own microcode (in S/360 it was marketed feature with high value, because with custom microcode, 360 could run software compiled for older hardware like 1401 or 7xx/7xxx series). And I agree with you, RISC achieve market adoption, when micro-processor (one-chip CPU) market share become so large, that these games with compatibility with old machines become non interest financially. So, as resume, I say, RISC machines are not players of CISC market, they are essentially players of micro-market, which in mid 1980s was not much more than games and terminals for mainframes and mini's (micro with, say 128k RAM is considerable to run accounting for small business but impossible to do more). In 1990s, RAM become so cheap, micro's swallowed mini's market, and appear clouds, so become possible to run large enterprise accounting on micro hardware. And at that moment, created Alpha, and than AMD-K8, which was essentially Alpha with hardware translator of x86 instructions to RISC. So, after all these adventures, RISC entered market via back door :)
- simne 3y ago
  To avoid misunderstanding, as I understand from mainframe talks, many of them was customizable like modern FPGA machines, as they even considered make custom hardware (imagine, you could order fully custom machine with additional registers, custom ALU, etc), that's why I compare custom microcode of CISC to FPGA, and why I think it is lost feature, just not existing in mini's and in micro's.
bitwize 3y ago
Doesn't matter. Generic CPUs were getting 32-bit word lengths and increased speed, and Lisp compiler technology had improved to yield fast code on those CPUs. The maker of Golden Common Lisp partnered with a hardware company to make a "Lisp machine on an ISA card" solution for PCs called the Hummingboard (not to be confused with present-day SBCs using that name). It was just a 386 and gobs of memory on a card. (this predates the Compaq 386-based PC). A special build of Golden CL sent compiled code to be executed on the 386 instead of the PC's main CPU.

by thesz 3y ago

kryptiskt 3y ago

But they weren't looking at ARM, they were looking at MIPS, which handily outperformed them at the time. ARM wasn't on their radar at all, since that was an oddball UK chip not used by any of their competitors. Symbolics competed in the very expensive workstation market, their machines cost more than most in that category, so they had to keep up the performance of MIPS R2000.

thesz 3y ago
MIPS (R2000) did not outdone Intel and/or Motorola at the time, those last, but not least two enjoyed all "economics of scale" of the world. MIPS was slower clock-frequency-wise than competitive offerings from Intel and/or Motorola and better pipeline design of MIPS did not add much. Complex expensive workstation like IRIS used proprietary hardware to boost I/O bandwidth and/or to have several CPUs working in parallel. It was easier for SGI to make CPUs and other hardware around them in accord and I honestly think that Symbolics was able to pull something like that.
simne 3y ago
As I hear, ARM at beginning was near pure educational chip, or toy for mature boys. MIPS grown on very different soil, it was from beginning pushed by business shark. Only much later, created ARM holding and they pushed ARM architecture to mass market, but even now their behavior looking strangely lazy, as for me.

simne 3y ago

This is not fair compare. Motorola and Intel that time outperforms first RISC machines, because have much better silicone level (even when logic level was not best). But game consoles are fair, as they was specialized machines, made with good silicone and with large scale production. On the same time, I'm not agree to consider 68020 as genuine CISC machine - I think it is more fair to consider it hybrid - RISC-optimized CISC (or, as it named on rumor talks - "mini on one chip"). I think, genuine CISC machines was most S/360 and some mini-machines, like Alto in which was documented feature to develop your own microcode (in S/360 it was marketed feature with high value, because with custom microcode, 360 could run software compiled for older hardware like 1401 or 7xx/7xxx series). And I agree with you, RISC achieve market adoption, when micro-processor (one-chip CPU) market share become so large, that these games with compatibility with old machines become non interest financially. So, as resume, I say, RISC machines are not players of CISC market, they are essentially players of micro-market, which in mid 1980s was not much more than games and terminals for mainframes and mini's (micro with, say 128k RAM is considerable to run accounting for small business but impossible to do more). In 1990s, RAM become so cheap, micro's swallowed mini's market, and appear clouds, so become possible to run large enterprise accounting on micro hardware. And at that moment, created Alpha, and than AMD-K8, which was essentially Alpha with hardware translator of x86 instructions to RISC. So, after all these adventures, RISC entered market via back door :)

simne 3y ago
To avoid misunderstanding, as I understand from mainframe talks, many of them was customizable like modern FPGA machines, as they even considered make custom hardware (imagine, you could order fully custom machine with additional registers, custom ALU, etc), that's why I compare custom microcode of CISC to FPGA, and why I think it is lost feature, just not existing in mini's and in micro's.

bitwize 3y ago

Doesn't matter. Generic CPUs were getting 32-bit word lengths and increased speed, and Lisp compiler technology had improved to yield fast code on those CPUs. The maker of Golden Common Lisp partnered with a hardware company to make a "Lisp machine on an ISA card" solution for PCs called the Hummingboard (not to be confused with present-day SBCs using that name). It was just a 386 and gobs of memory on a card. (this predates the Compaq 386-based PC). A special build of Golden CL sent compiled code to be executed on the 386 instead of the PC's main CPU.