4 ms·

You could have a CPU that updates itself to be able to emulate whatever new features come along in x86/AMD64 to therefore be 'future proof'. Even if the raw per

You could have a CPU that updates itself to be able to emulate whatever new features come along in x86/AMD64 to therefore be 'future proof'. Even if the raw performance is not at the same level as the genuine Intel, does it matter if merely surfing the web? If performance is 'ample' then the CPU that just gets updated to include new instructions could make it so computers could last for decades doing things like showing web pages. How hard can that get?

SCHiM 12y ago
Many instructions on your cpu are already 'micro coded' instead of wired into the hardware. I'm not 100% sure on how it works, or what it is. But it sounds like what you're proposing could already be implemented in modern cpus. https://en.wikipedia.org/wiki/Microcode https://en.wikipedia.org/wiki/Microcode
- xenophonf 12y ago
  The DEC Alpha AXP did this in something called PALcode. Unimplemented instructions generated a CPU interrupt that got handled by a PALcode emulator. If I recall correctly, one of the things it did was emulate byte-wise memory operations on older processors that could only do loads and stores on double-word- or quad-word-aligned memory addresses. It was quite a bit slower than having the requisite silicon inside the CPU itself, but I don't have the numbers available. I miss the Alphas. Those machines were _awesome_.
  - agumonkey 12y ago
    A hardware instance of http://c2.com/cgi/wiki?DoesNotUnderstand http://c2.com/cgi/wiki?DoesNotUnderstand.
- sliverstorm 12y ago
  Microcode is a special unit in the decoder. When a microcoded instruction is detected in the codestream, it is stopped and replaced by a stream of instructions from the microcode ROM. Imaginary example: mul 37 -1 Could be automatically identified and replaced with a predetermined codestream of: add (not 37) 1 This allows super complicated instructions (of which x86 has many) to be implemented with simple instructions, and it also allows the designer to work around bugs that might be discovered later on.
  - kuschku 12y ago
    in x86, it's even worse - there are microcode translators, with the microcode running on special small ALUs, with their own code caches.
  - dfox 12y ago
    That is the "x86 on RISC-ish core" interpretation of term microcode, which is probably not exactly correct as far as the actual implementations go. As a technical term, microcode is contents of memory that is used to implement CPU sequencing (in contrast to doing sequencing in hardwired random logic or having essentially no sequencing logic as is the case in classical RISC designs). In most straightforward implementation it's essentially turing machine with microcode as state table and tape replaced by rest of the CPU. Various enhancements and modifications are possible which end in having essentially full-blown CPU for processing microcode, but even in that case one thing is critical for the term: the microcode only handles control functions (sequencing) and does not directly process data.
x0054 12y ago
Why on earth do you need the latest CPU architecture to browse the web. I have a laptop from 2002 and it runs chrome and browses the web just find. What on earth are you talking about?
- dogma1138 12y ago
  Try playing a 1080p video on youtube on it :)
  - x0054 12y ago
    Fair enough, but I doubt the latest CPU features would help me in that regard :) With more HTML5 dynamic stuff it's also becoming very slow as well. I really only use it to control my DSLR.
  - pmarin 12y ago
    No 1080p screens in 2002 laptops.
    - pareidolia 12y ago
      More like 1920x1200 :)
    - dogma1138 12y ago
      Funny cuz the 2 laptops I've had in 2002-2003 had either a 1600x1200 or the weird 1400x1050 resolution which was popular for 5:4 14-15" panels at the time. Heck with "720/1080p" screens becoming popular there was actually quite a decrease in the overall resolution in laptop screens between say 2005 to 2012 with 720 and 800/900 vertical resolutions screens being produced instead of the good old 1000+ vertical resolution screens we had previously. I didn't want to upgrade a laptop for almost 2 years because i wouldn't use a screen with so little vertical real estate, now with 1440-2160p screens becoming popular again it's a very good time indeed. And I hope that 3:2 screens actually catch up, I've been using a 1440x1440 screens now for some months now and the square format is just amazing for productivity, nothing is outside of your focus and they are just awesome for half screen vertical tiling.
toast0 12y ago
Very little software is written that requires features from the latest CPU updates. There's not much of a need to address compatibility by emulating new features in the CPU itself. Windows 8 needs PAE, NX, and SSE2, which were available in cpus produced 8 years before release (certainly not all cpus produced in 2004 had these features, but many did).
sliverstorm 12y ago
The few truly new features that have come along are not really emulate-able. Things like 64 bit, or new secure modes. Most everything else has been bundles of hardware accelerated instructions for performance gains on popular data classes (see: MMX, AVX256, etc). It's rare you run into software that doesn't have multiple codepaths, leveraging an extension if you have it and bypassing it if you don't. Extensions that you are defacto required to have are so old, you almost certainly have them anyway. MMX was introduced in 1997 in the P5. MMX support will not be the first problem on your list if you're trying to run modern software on a P4.

SCHiM 12y ago

Many instructions on your cpu are already 'micro coded' instead of wired into the hardware. I'm not 100% sure on how it works, or what it is. But it sounds like what you're proposing could already be implemented in modern cpus. https://en.wikipedia.org/wiki/Microcode https://en.wikipedia.org/wiki/Microcode

xenophonf 12y ago
The DEC Alpha AXP did this in something called PALcode. Unimplemented instructions generated a CPU interrupt that got handled by a PALcode emulator. If I recall correctly, one of the things it did was emulate byte-wise memory operations on older processors that could only do loads and stores on double-word- or quad-word-aligned memory addresses. It was quite a bit slower than having the requisite silicon inside the CPU itself, but I don't have the numbers available. I miss the Alphas. Those machines were _awesome_.
- agumonkey 12y ago
  A hardware instance of http://c2.com/cgi/wiki?DoesNotUnderstand http://c2.com/cgi/wiki?DoesNotUnderstand.
sliverstorm 12y ago
Microcode is a special unit in the decoder. When a microcoded instruction is detected in the codestream, it is stopped and replaced by a stream of instructions from the microcode ROM. Imaginary example: mul 37 -1 Could be automatically identified and replaced with a predetermined codestream of: add (not 37) 1 This allows super complicated instructions (of which x86 has many) to be implemented with simple instructions, and it also allows the designer to work around bugs that might be discovered later on.
- kuschku 12y ago
  in x86, it's even worse - there are microcode translators, with the microcode running on special small ALUs, with their own code caches.
- dfox 12y ago
  That is the "x86 on RISC-ish core" interpretation of term microcode, which is probably not exactly correct as far as the actual implementations go. As a technical term, microcode is contents of memory that is used to implement CPU sequencing (in contrast to doing sequencing in hardwired random logic or having essentially no sequencing logic as is the case in classical RISC designs). In most straightforward implementation it's essentially turing machine with microcode as state table and tape replaced by rest of the CPU. Various enhancements and modifications are possible which end in having essentially full-blown CPU for processing microcode, but even in that case one thing is critical for the term: the microcode only handles control functions (sequencing) and does not directly process data.

x0054 12y ago

Why on earth do you need the latest CPU architecture to browse the web. I have a laptop from 2002 and it runs chrome and browses the web just find. What on earth are you talking about?

dogma1138 12y ago
Try playing a 1080p video on youtube on it :)
- x0054 12y ago
  Fair enough, but I doubt the latest CPU features would help me in that regard :) With more HTML5 dynamic stuff it's also becoming very slow as well. I really only use it to control my DSLR.
- pmarin 12y ago
  No 1080p screens in 2002 laptops.
  - pareidolia 12y ago
    More like 1920x1200 :)
  - dogma1138 12y ago
    Funny cuz the 2 laptops I've had in 2002-2003 had either a 1600x1200 or the weird 1400x1050 resolution which was popular for 5:4 14-15" panels at the time. Heck with "720/1080p" screens becoming popular there was actually quite a decrease in the overall resolution in laptop screens between say 2005 to 2012 with 720 and 800/900 vertical resolutions screens being produced instead of the good old 1000+ vertical resolution screens we had previously. I didn't want to upgrade a laptop for almost 2 years because i wouldn't use a screen with so little vertical real estate, now with 1440-2160p screens becoming popular again it's a very good time indeed. And I hope that 3:2 screens actually catch up, I've been using a 1440x1440 screens now for some months now and the square format is just amazing for productivity, nothing is outside of your focus and they are just awesome for half screen vertical tiling.

toast0 12y ago

Very little software is written that requires features from the latest CPU updates. There's not much of a need to address compatibility by emulating new features in the CPU itself. Windows 8 needs PAE, NX, and SSE2, which were available in cpus produced 8 years before release (certainly not all cpus produced in 2004 had these features, but many did).

sliverstorm 12y ago

The few truly new features that have come along are not really emulate-able. Things like 64 bit, or new secure modes. Most everything else has been bundles of hardware accelerated instructions for performance gains on popular data classes (see: MMX, AVX256, etc). It's rare you run into software that doesn't have multiple codepaths, leveraging an extension if you have it and bypassing it if you don't. Extensions that you are defacto required to have are so old, you almost certainly have them anyway. MMX was introduced in 1997 in the P5. MMX support will not be the first problem on your list if you're trying to run modern software on a P4.