Odds & Ends: ECC & NVIDIA Surround Missing

One of the things we have been discussing with NVIDIA for this launch is ECC. As we just went over in our GF100 Recap, Fermi offers ECC support for its register file, L1 cache, L2 cache, and RAM. The latter is the most interesting, as under normal circumstances implementing ECC requires a wider bus and additional memory chips. The GTX 400 series will not be using ECC, but we went ahead and asked NVIDIA how ECC will work on Fermi products anyhow.

To put things in perspective, for PC DIMMs an ECC DIMM will be 9 chips per channel (9 bits per byte) hooked up to a 72bit bus instead of 8 chips on a 64bit bus. However NVIDIA doesn’t have the ability or the desire to add even more RAM channels to their products, not to mention 8 doesn’t divide cleanly in to 10/12 memory channels. So how do they implement ECC?

The short answer is that when NVIDIA wants to enable ECC they can just allocate RAM for the storage of ECC data. When ECC is enabled the available RAM will be reduced by 1/8th (to account for the 9th ECC bit) and then ECC data will be distributed among the RAM using that reserved space. This allows NVIDIA to implement ECC without the need for additional memory channels, at the cost of some RAM and some performance.

On the technical side, despite this difference in implementation NVIDIA tells us that they’re still using standard Single Error Correction / Double Error Detection (SECDED) algorithms, so data reliability is the same as in a traditional implementation. Furthermore NVIDIA tells us that the performance hit isn’t a straight-up 12.5% reduction in effective memory bandwidth, rather they have ways to minimize the performance hit. This is their “secret sauce” as they call it, and it’s something that they don’t intend to discuss at in detail at this time.

Shifting gears to the consumer side, back in January NVIDIA was showing off their Eyefinity-like solutions 3DVision Surround and NVIDIA Surround on the CES showfloor. At the time we were told that the feature would launch with what is now the GTX 400 series, but as with everything else related to Fermi, it’s late.

Neither 3DVision Surround nor NVIDIA surround are available in the drivers sampled to us for this review. NVIDIA tells us that these features will be available in their release 256 drivers due in April. There hasn’t been any guidance on when in April these drivers will be released, so at this point it’s anyone’s guess whether they’ll arrive in time for the GTX 400 series retail launch.

The GF100 Recap Tessellation & PhysX
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  • Matt Campbell - Monday, August 02, 2010 - link

    Ryan, what was the special sauce you used to get Badaboom working on Fermi? My GTX 460 won't run it, and Elemental's website says Fermi support won't get added until Q4 2010. http://badaboomit.com/node/507 Reply
  • niceboy60 - Friday, August 20, 2010 - link

    I have the same probleme on my GTX 480 , Badaboom does not work on fermi ,according with my own experience and Badaboom official web site
    I dont think this benchmarks are accurate
    Reply
  • niceboy60 - Friday, August 20, 2010 - link

    I bought a GTX 480 based on this review as I do a considerable amount of video converting
    Just to find out ,dispite the GTX 480 is showing very good resaults when using Badaboom
    The truth is Badaboom is not compatible yet with any GTX 400 series according with The badaboom web site .
    Reply
  • adder1971 - Friday, September 17, 2010 - link

    The Badaboom website says it does not work and when I try it with the GTX 465 it does not work. How were you able to get it to work? I have the NVIDIA latest release drivers as of today and the latest released version of Badaboom. Reply
  • wizardking - Tuesday, September 21, 2010 - link

    I bought this card for it only ! I used badaboom with number which you use !!!!!! Reply
  • IcarusLSC - Wednesday, September 22, 2010 - link

    How'd you set the 4x + TrSS 4x mode in Battlefield BC2? I can't find anythign that resembles it in the nVidia panel at all to force it etc...
    Thanks!
    Reply
  • jmkayu - Thursday, October 14, 2010 - link

    Please do yourselves a favour, do not believe every paid review you see, and listen to actual users. In an unprecedented move of arrogance, nVidia has intentionally crippled the entire 400 series performance for anything but mainstream games. When 8000 series handily outperform the new 400, we have a problem. Check the following user discussions, and especially the last one from a developer.

    http://forums.nvidia.com/index.php?showtopic=18157...
    http://forums.nvidia.com/index.php?showtopic=16675...
    http://www.opengl.org/discussion_boards/ubbthreads...
    http://news2.mcneel.com/scripts/dnewsweb.exe?cmd=a...
    Reply

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