5 ms·

Why would Alpha be the worst? I’ve owned 2 of them, 21064 and 21264, and they were fast and reliable.

als0 4y ago
The influence of Alpha on modern instruction sets like ARM64 and RISC-V is tremendous. It’s just sad it had to die for this to happen.
- scrlk 4y ago
  I'd also add that a lot of excellent ex-Alpha engineers (e.g. Jim Keller, Dan Dobberpuhl off the top of my head) ended up designing great chips at other companies.
- hajile 4y ago
  It didn't die. Intel bought it from HP, stripped it for parts, then killed it. HyperTransport and a few other things were essentially just copies of Alpha's stuff cleanroom implemented by ex-Alpha employees. Designs like Sandy Bridge look quite similar to EV8. QuickPath is just Alpha's interconnect with some updates (HyperTransport was also a cleanroom copy from ex-Alpha employees). Even AVX seems inspired by the 1048-bit SIMD planned for EV9/10.
- jeffbee 4y ago
  How did the Alpha ISA influence RISC-V, other than by its counterexample? Does RISC-V lack an integer divide? "Design of the RISC-V Instruction Set Architecture" mainly uses Alpha in the phrase "Unlike Alpha, ..." i.e. as a warning to future people. In fact, the author fairly well excoriates all of the historic RISC architectures for being myopically designed.
  - ncmncm 4y ago
    Give RISC-V time, it will be somebody's bad example soon enough.
chasil 4y ago
The only two architectural questions that I know of were... The weak memory model: https://devblogs.microsoft.com/oldnewthing/20170817-00/?p=96835 https://devblogs.microsoft.com/oldnewthing/20170817-00/?p=96... Inability to address low-power designs: https://en.m.wikipedia.org/wiki/StrongARM https://en.m.wikipedia.org/wiki/StrongARM "According to Allen Baum, the StrongARM traces its history to attempts to make a low-power version of the DEC Alpha, which DEC's engineers quickly concluded was not possible." The other major problem with the Alpha was the high license costs of DEC operating systems, which greatly helped put it in the grave.
- masklinn 4y ago
  And incapable of working with unaligned values or values smaller than 4 bytes. Weren’t there also cache coherence issues? Alpha kinda had you finish the hardware in software.

als0 4y ago

The influence of Alpha on modern instruction sets like ARM64 and RISC-V is tremendous. It’s just sad it had to die for this to happen.

scrlk 4y ago
I'd also add that a lot of excellent ex-Alpha engineers (e.g. Jim Keller, Dan Dobberpuhl off the top of my head) ended up designing great chips at other companies.
hajile 4y ago
It didn't die. Intel bought it from HP, stripped it for parts, then killed it. HyperTransport and a few other things were essentially just copies of Alpha's stuff cleanroom implemented by ex-Alpha employees. Designs like Sandy Bridge look quite similar to EV8. QuickPath is just Alpha's interconnect with some updates (HyperTransport was also a cleanroom copy from ex-Alpha employees). Even AVX seems inspired by the 1048-bit SIMD planned for EV9/10.
jeffbee 4y ago
How did the Alpha ISA influence RISC-V, other than by its counterexample? Does RISC-V lack an integer divide? "Design of the RISC-V Instruction Set Architecture" mainly uses Alpha in the phrase "Unlike Alpha, ..." i.e. as a warning to future people. In fact, the author fairly well excoriates all of the historic RISC architectures for being myopically designed.
- ncmncm 4y ago
  Give RISC-V time, it will be somebody's bad example soon enough.

chasil 4y ago

The only two architectural questions that I know of were... The weak memory model: https://devblogs.microsoft.com/oldnewthing/20170817-00/?p=96835 https://devblogs.microsoft.com/oldnewthing/20170817-00/?p=96... Inability to address low-power designs: https://en.m.wikipedia.org/wiki/StrongARM https://en.m.wikipedia.org/wiki/StrongARM "According to Allen Baum, the StrongARM traces its history to attempts to make a low-power version of the DEC Alpha, which DEC's engineers quickly concluded was not possible." The other major problem with the Alpha was the high license costs of DEC operating systems, which greatly helped put it in the grave.

masklinn 4y ago
And incapable of working with unaligned values or values smaller than 4 bytes. Weren’t there also cache coherence issues? Alpha kinda had you finish the hardware in software.