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
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  • SiliconDoc - Friday, September 25, 2009 - link

    LOL - you won't find me arguing, but that performance per dollar here is absolutely FAMOUS for guess whom, ati !
    Congratulations, for the first time someone other than myself conplained about it, of course, only when ATI has been implicated as a disaster in it.
    --
    PS - I think what the chart is saying is, use some common sense, not go for 9500, but in your range you hope to purchase, the chart can be handy for picking between several.
    --
    Also, the chart tells us, the 5870 is not bang for the buck.
    -
    So, so sorry, it upset you so badly, the tips above for proper useage should be fine.
  • KaarlisK - Wednesday, September 23, 2009 - link

    Actually, far more developers care about the next version of DirectX (pc-industry-wide vendor-independent development platform) than about PhysX (single vendor, low uptake currently). Not that PhysX would be unimportant.
  • SiliconDoc - Wednesday, September 23, 2009 - link

    Not quite time yet, you can "pre-order" one of 3 versions at tiger..LOL
    This is not a "hard launch", this is a red RUSE !
    --
    http://www.tigerdirect.com/applications/SearchTool...">http://www.tigerdirect.com/applications/SearchTool...
  • SiliconDoc - Wednesday, September 23, 2009 - link

    Ok, hurry, the paper launch finally "cracked" a bit and there's one card of 4 5870's on newwegg that is suposedly "available for purchase".
    http://www.newegg.com/Product/ProductList.aspx?Sub...">http://www.newegg.com/Product/ProductLi...1&na...
    It's 1:33pm on the 23rd, so no guarantees there's more than 0 for actual sale....
    Good luck on getting something other than paper. :-)
  • jabroni619 - Wednesday, September 23, 2009 - link

    I'd better not get paper... I was able to place an order at newegg at midnight when they were available and 18 hours later it's showing a status of shipped. ;)
  • SiliconDoc - Wednesday, September 23, 2009 - link

    7:08PM CST Wed. Sept 23rd, 2009 -
    Out of the 9 "reviews" by "customers" on newegg for the 5870 card, only ONE of them has the revealing:
    " This user purchased this item from Newegg " in blue by their name on the customer reviews tab.
    LOL
    So it looks like 8 posers and you. Hope you enjoy the XFX 5870,
    "WoostaR"
  • WoostaR - Friday, October 2, 2009 - link

    Thanks man, I actually went with 2 5870's. I know it's bit of overkill, yet future proof is better =)

    anyways, I have gotten over 17000 of 3dMark06. That's with Cpu.

    I am running Core i7 @ 4 ghz
    6GB of Gskill ram
    Dual 5870 @ CF
    750W Corsair.
    EVGA 3x SLI
  • jabroni619 - Thursday, September 24, 2009 - link

    Oh, and I didn't get the XFX, I got HIS. XFX wasn't even showing up when I placed my order. Only Sapphire, ASUS and HIS were, both the Sapphire and ASUS were OOS.
  • jabroni619 - Thursday, September 24, 2009 - link

    I haven't written a review yet as I haven't gotten the card. (hate it when people do that) I was a little worried up until just a few minutes ago when my UPS tracking# actually had some data. Estimated Delivery of 9/24/09. Hopefully it's waiting at the front door when I get home from work. I just spend the last 2 hours moving all the guts of my PC into a larger case to accommodate the card.
  • SiliconDoc - Friday, September 25, 2009 - link

    Apparently your luck is immaculate.
    http://www.fudzilla.com/content/view/15673/1/">http://www.fudzilla.com/content/view/15673/1/
    " We talked to partners and some of them might have a few cards next week and October is the month when things should get better.

    The big guys such as Newegg and Tigerdirect don’t have them, and in EU, a hundred plus cards are listed here, but none of them are available.

    A launch partner in the UK got 20 cards ...
    We hope that Radeon 5870 is not what AMD management calls a hard launch "
    ROFL - At least one place doesn't have to censor itself

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