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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  • Sunburn74 - Sunday, March 28, 2010 - link

    It is absolutely ridiculous. Like having a buzzsaw in your case.
    http://www.hardocp.com/article/2010/03/26/nvidia_f...">http://www.hardocp.com/article/2010/03/26/nvidia_f...
    Reply
  • Belard - Sunday, March 28, 2010 - link

    AMD already stated they are not reducing their pricing any time soon. This is because their line-up is far healthier than Nvidia.

    They know (and we should know) that the $500/$350 price for the new GeForce 4 cards are not going to stick. There is only some many thousands of cards available for the next 3~5 months. The supply will run dry in about 1-3 weeks I bet. We're going to see the pricing shoot up close to $600 for the GF480, the fanboyz will be willing to pay that price.

    The 5850 was supposed to be a $250 card, we see how well that worked out. While the price did settle around $300, the 5850 was still a better value than the $370~400 GeForce 285 card as it was far faster and run cooler, etc. The 5870 is typically faster than the $500 GeForce 295 - for $100 less. ATI has no reason to lower their pricing.

    The GeForce 265~295 cards are already being phased out, too slow, cost too much.

    So nVidia has nothing for the sub $300 market... nothing. Only the GF-250 has any value but a tad expensive as it should be $100 since its still a DX10 re-badged 9800GTX.

    So when ATI feels any pressure from Nvidia, they can easily drop their prices. It costs $5000 per wafer, no matter how many chip dies are on it. It may be costing nVidia $150~200 per chip while for AMD, they could be paying $20~35 per chip used in the 5800/5900s.
    Then you add the costs for memory, the PCB, parts, cooling system etc.

    It is very easy for AMD to drop $50 per GPU and they'd still make a profit while Nvidia sells their geForce 400 cards at a loss or no profit.

    When ATI sells the 5830 for $190~200, 5850 at $250 and 5870 at $325~350 would help sales and keep nVidia at bay.

    We'll see...
    Reply
  • SirKronan - Sunday, March 28, 2010 - link

    I would've liked to see 5850's in crossfire thrown into this mix. I know you don't have time to test them all, but I think that's the key competitor against the 480 when it comes to bang/buck. I would think the 5850's in crossfire could handily beat the 295 and the 480, all while consuming less power. I believe there may have been another site that did it, but with this excellent and very thorough review done here, it would've been even that little tiniest bit sweeter to have a 5850 crossfire line on their graphs.

    Regardless, thanks for the informative review!
    Reply
  • B3an - Saturday, March 27, 2010 - link

    This review and any other pages on this site are not working in Firefox... they have been reported as attack pages.

    "This web page at www.anandtech.com has been reported as an attack page and has been blocked based on your security preferences."

    This is why FF with all default settings, and just using adlock.
    Could it be trouble with the ads again using a malware/virus?
    Reply
  • Ryan Smith - Sunday, March 28, 2010 - link

    We know. It's being worked on. Reply
  • Sunburn74 - Saturday, March 27, 2010 - link

    The 5850 idles inthe mid 30's but it also does absolutely nothing to stay cool, operating at about 20% max fan speed. Under load it may go up to 30% fan speed, but rarely ever breaks the 40% mark.

    What are the approximate idle and load fan speeds for both the gtx 480 and 470? I guess I'm asking this to understand just how much extra cooling room is innately available. Are these card working at max capacity to keep cool or is there thermal/fan headroom there to be had?
    Reply
  • Ryan Smith - Saturday, March 27, 2010 - link

    I don't have that data on-hand (we don't record fan speeds), but it's something that I should be able to easily grab at a later time. Reply
  • Lemonjellow - Saturday, March 27, 2010 - link

    For some reason Chrome is flagging this article as a malicious sight... Oddness... Possibly got a bad advertisement... Reply
  • NJoy - Saturday, March 27, 2010 - link

    well, Charlie was semi-accurate, but quite right =))What a hot chick... I mean, literately hot. Way too hot Reply
  • WiNandLeGeNd - Saturday, March 27, 2010 - link

    Looking back at the data, I realized that power consumption is for system total. Guru3d measured the power consumption of the card itself and reported a max of 263W, so roughly 21 A. I think my 850W will do just fine since each PCI-X con has 20A each. Reply

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