A Quick Refresher on the RV770

As Cypress is a direct evolution of the RV770 design, before we talk about what’s new with Cypress we are going to go over a quick rehash of RV770’s internal workings. As it’s necessary to understand how RV770 was built to understand what Cypress changes, if you’re completely unfamiliar with RV770, please take a look at our expanded discussion of RV770 from last year. For the rest of you, let’s get started.

At the center of the RV770 is the Stream Processing Unit (SPU), a single arithmetic logic unit. The RV770 has 800 of these, and they are packaged together in groups of 5 and are what we call a Streaming Processor (SP). A SP contains a register file, a branch predictor, and the aforementioned 5 SPUs, with the 5th SPU being a more complex unit capable of transcendental functions along with the base functions of an ALU. The SP is the smallest unit that can do individual work; every SPU in an SP must execute the same instruction.

For every 16 SPs, AMD groups them together with texture units, L1 cache, shared memory, and controlling logic. This combined block is what AMD calls a SIMD, and RV770 has 10 of them. These 10 SIMDs form the core computational power of the RV770, and in the chip work with various specialized units such as ROPs, rasterizers, L2 cache, and tesselators to form a complete chip.

To utilize the computational power of the hardware, instruction threads are issued to the SPs. These threads are grouped into wavefronts, where there are 64 threads per wavefront. To maximize the utilization of the GPU, threads need to be organized so that they can feed all 5 SPUs in a SP an instruction every clock cycle. Doing this requires extracting instruction level parallelism (ILP) out of programs being passed to the GPU, which is difficult task of AMD’s compiler.

If SPUs go unused, then the performance of the chip suffers due to underutilization. This design gives AMD a great deal of theoretical computational power, but it is always a challenge to fully exploit it.

Meet the Rest of the Evergreen Family Cypress: What’s New


View All Comments

  • Qfromchicago - Friday, November 27, 2009 - link

    Windows 7 Profession
    Onkyo 805
    Diamond 5870
    Still no 3rd option for hd audio.

    Has anyone been able to work this thing
  • charme - Friday, November 27, 2009 - link

    same here.
    no 3rd option for hd audio
  • otni - Sunday, November 29, 2009 - link

  • FlyTexas - Saturday, November 14, 2009 - link

    What good does it do to launch this, if there are still none for sale a month later?

    Yes, I know there were a few sold up front, but NewEgg has been out for awhile...
  • RavnosCC - Tuesday, November 17, 2009 - link

    The 57xx series are readily available, they also support HD Audio. Reply
  • RavnosCC - Monday, November 23, 2009 - link

    "As of today, new PowerDVD 9 Ultra customers will receive build 2320, which includes support for HDMI bitstreaming of undecoded (full quality) audio with ATI Radeon 5000 series graphics cards, and the Auzentech X-Fi Hometheater HD sound card. An update patch for current owners of PowerDVD 9 Ultra is scheduled to be available next Friday (11/27).

  • Qfromchicago - Wednesday, November 25, 2009 - link

    Though happy that finally we will get hd audio using powerdvd, but why limit it to new customers only. It seems to me that if you can offer it to new customers, you should be able to offer it to everyone at the same time. Reply
  • Qfromchicago - Sunday, October 18, 2009 - link

    I have win 7, a diamond 5870, powerdvd 9 ultra version 2201 and still I don't get he 3rd choice for the HD audio bitstreaming. Has anyone been able to get bitstreaming to work with powerdvd 9. Thanks Reply
  • RavnosCC - Thursday, November 05, 2009 - link

    UPDATE: Looks like late November for the mythical patch...

    "Hi everyone,
    Yes... we read these forums regularly. Feedback is forwarded to the appropriate people. These forums aren't the best way for us to provide customer support, so if you have an issue, please open a support ticket through our website.

    We can't always comment on new developments... or at least we like to wait until we have a definite answer. I know everyone noticed the reviews for the ATI Radeon 5000 series graphics cards, where certain reviewers were using a pre-release version of PowerDVD 9 to demonstrate HDMI bitstreaming of Blu-ray audio. Support for this feature will be in the next PowerDVD update (patch), which will be available later this month. I don't have a firm date on this, but we're trying to expedite it. Please keep in mind that each of our regular updates includes fixes for new BD titles and new (or forthcoming) hardware / drivers across the PC ecosystem, and so the feature you are anxiously waiting for isn't the only thing that we need to include in the update. Of course, each update has to go through a full quality assurance testing procedure, to make sure that none of the changes introduced any new issues.

    So... sorry for going quiet on you... but I and others read every post in this thread and other relevant threads, following up as needed (in some cases, directly through private messages on these forums).

  • RavnosCC - Wednesday, October 28, 2009 - link

    I am in the same boat, with Vista, I have powerdvd 9 ultra fully patched and still no third option for hi-def passthrough... :-/ Reply

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