Sign in with
Sign up | Sign in

AMD Drops 3DNow! Support From Future CPUs

By - Source: Tom's Hardware US | B 38 comments

3DNow! has become 3DNo More!

It really doesn't feel like it was that long ago when AMD introduced its own SIMD extensions called 3DNow!, but it's been long enough now that the chip company is sending the technology out to pasture.

AMD announced last week that 3DNow! is deprecated and will not be supported in certain upcoming AMD processors and will not have that feature flag bit set.

What does this mean for those who make software using these AMD instructions?

If your software used 3DNow! instructions at any point in time you should confirm that you only take that code path after checking to see if the feature is supported during runtime, using CPUID.

Most likely, your code already has another code path to take, such as an SSE path, if 3DNow! instructions are not supported.  To reiterate, make sure that the code uses feature bits to determine when the code should take this path.  If the code uses the vendorID string rather than a feature bit to make the path determination, AMD processors that support SSE may end up taking a slower path as a result.

Read the full post from the AMD developer blog.

Discuss
Ask a Category Expert

Create a new thread in the News comments forum about this subject

Example: Notebook, Android, SSD hard drive

This thread is closed for comments
Top Comments
  • 27 Hide
    mavroxur , August 24, 2010 1:08 PM
    3DNow! has been surpassed by....how many code extensions? And if your software supported 3DNow!, the software will still run, just without the extensions now. Which might be a performance issue....if your software wasn't 15 years old and designed to run on K6-2 CPU's anyways. So the 10% performance hit you take from no 3DNow! will be canceled by the 1000000% performance gain from a modern CPU :-)
  • 25 Hide
    jj463rd , August 24, 2010 12:34 PM
    Oh yeah I remember the 3DNow extensions on my old K6-2 CPU from 1998.
  • 16 Hide
    Xatos , August 24, 2010 1:21 PM
    ^ Exactly.
Other Comments
    Display all 38 comments.
  • 15 Hide
    decode , August 24, 2010 12:19 PM
    Barely even knew about this feature, except that I had it, Lol!
  • 14 Hide
    pogsnet , August 24, 2010 12:33 PM
    This feature started before SSE comes out in Pentium III era
  • 25 Hide
    jj463rd , August 24, 2010 12:34 PM
    Oh yeah I remember the 3DNow extensions on my old K6-2 CPU from 1998.
  • 16 Hide
    San Pedro , August 24, 2010 12:39 PM
    Those of you playing still playing Quake 2 (wouldn't blame you) are out of luck.
  • -8 Hide
    Mottamort , August 24, 2010 12:44 PM
    So my Quake 2 is going to run slightly slower..? :(  /sarcasm
  • 9 Hide
    ajcroteau , August 24, 2010 1:07 PM
    3DNow was huge back in the day... I had a couple of K6-2 cpu's and both ran fairly well... but it looks like it's gone the way of the dinosaurs...
  • 27 Hide
    mavroxur , August 24, 2010 1:08 PM
    3DNow! has been surpassed by....how many code extensions? And if your software supported 3DNow!, the software will still run, just without the extensions now. Which might be a performance issue....if your software wasn't 15 years old and designed to run on K6-2 CPU's anyways. So the 10% performance hit you take from no 3DNow! will be canceled by the 1000000% performance gain from a modern CPU :-)
  • 16 Hide
    Xatos , August 24, 2010 1:21 PM
    ^ Exactly.
  • 2 Hide
    COLGeek , August 24, 2010 1:45 PM
    Things change. 3DNow! served its purpose and that is now behind us. In the day, 3DNow! was cool, but not often used so its passing at a time when CPUs are so much more advanced could have passed without an AMD announcement (except in the old dude SW dev world). BTW, I am one of those old dudes.
  • 7 Hide
    Shin-san , August 24, 2010 1:50 PM
    This makes sense. There have been so many CPU extensions like SSE that have replaced 3DNow! It's actually a requirement that SSE2 is standard in x64 CPUs
  • 9 Hide
    chick0n , August 24, 2010 1:54 PM
    Losing 3Dnow! is not really a big deal. We have all these fast CPU and now even GPU will be able to help crunching numbers really really fast.

    but my question is, does it take that much of a resource to "keep" 3Dnow! extension in the CPU logic? or is it causing some of the problems ?

    only AMD knows.
  • 3 Hide
    rocky1234 , August 24, 2010 2:03 PM
    Well even though it served it's purpose back in the day I do not think many or if any modern programs use it any longer. So if this makes more die space so AMD can ad other features into their CPU's I am all for it.

    I'm sure Quake 2 will run fine still without it..lol :) 
  • 4 Hide
    Sorax , August 24, 2010 2:17 PM
    I played the original Half-Life on a K6-2 in 1998. And continued to use it for years with TF and CS. So thanks for the wonderful memories 3DNow!
  • 1 Hide
    COLGeek , August 24, 2010 2:36 PM
    I actually still have a K6-2+ based Sony Vaio at home with a whopping 256MB of RAM running Puppy Linux. When we bought it for my wife, it was state of the art and came pre-loaded with Windows ME (that was removed within minutes of opening the box and replaced with Win2K).

    Even so, if I had to guess, the 3DNow! extensions were likely never used on this machine as it was never used for games.

    Regardless, it is cool to discuss these changes in the tech landscape.
  • 2 Hide
    harth13 , August 24, 2010 2:41 PM
    wikipedia says "The 3DNow! instruction set was created during the late 1990s when 3D graphics were exploding in popularity because of 3D gaming, and 3D games heavily use floating-point arithmetic."

    and i say old
  • -2 Hide
    Anonymous , August 24, 2010 3:16 PM
    AMD could have easily updated the 3D Now instruction set but for one reason, fusion, any amount of SSE will never come near to the power of a real gfx processor

    now i have to wonder if GPGPU does take off, will it make SSE new and old obsolete
  • -5 Hide
    iggybeans , August 24, 2010 3:30 PM
    As this decision affects backward compatibility, I personally view it as a negative.
  • 1 Hide
    orionantares , August 24, 2010 3:38 PM
    No surprise. AMD simpl wasn't extending 3DNow instead they were working wth Intel's SSE and helped extend that once or twice, especially in the AMD64 architecture.
  • 8 Hide
    2real , August 24, 2010 3:56 PM
    iggybeansAs this decision affects backward compatibility, I personally view it as a negative.

    are you thick? you can still play the games you'll just get 500 fps instead of 550
Display more comments