Thursday, January 19th 2012
GeForce Kepler 104 (GK104) Packs 256-bit GDDR5 Memory Bus, 225W TDP
NVIDIA GeForce Kepler (GK104) will be NVIDIA's first high-performance GPU launched, based on its Kepler architecture. New reports suggest that this GPU, which will succeed GF114 (on which the likes of GeForce GTX 560 Ti are based), will continue to have a 256-bit wide GDDR5 memory interface. An equally recent report suggests that NVIDIA could give the front-line product based on GK104 as much as 2 GB of memory. We are also getting to hear from the INPAI report that on this product based on the GK104, the GPU will have a TDP of 225W. What's more, NVIDIA is gunning for the performance crown from AMD Radeon HD 7900 series with this chip, so it suggests that NVIDIA is designing the GK104 to have a massive performance improvement over the GF114 that it's succeeding.
Source:
Inpai.com.cn
105 Comments on GeForce Kepler 104 (GK104) Packs 256-bit GDDR5 Memory Bus, 225W TDP
And for your mention, nVidia previous gen used 320 and 384 buswidth not a 256 bit like this. That means you need to increase memory clock to somewhat about 1600 - 1800 MHz for BW compensation.
1600 - 1800 MHz GDDR5, i mean... WooooooW thats must be a super special DDR5 :eek:
Nvidia used 384 bits on their high-end chip, GK104 is NOT high-end. High-end nowadays means GPGPU and GPGPU requires more bandwidth, that's why GF100/110 had a 384 bit bus, and same for Tahiti. High-end==GPGPU also means you need to leave headroom, it means you cannot make compromises, it means going overkill sometimes. Mid-range means you can take compromises, you can cut corners.
Besides GTX560 Ti used a 256 bit bus and 1000 Mhz memory, like I said. To match HD7970 performance they need 50% performance over the GTX560. They don't need 1600-1800 Mhz GDDR5 that's absurd. They don't even need the 40% that 1375 Mhz GDDR5 would bring, because GPU perf is not linearly related to memory bandwidth.
But, in many case, insufficient bandwidth can cause severe deduction in graphic performance. ( ex. HD5670 GDDR3 vs HD5670 GDDR5 )
so, u gonna tell me that the bandwidth of 6970 level is enough for 7970 performance.
where's the proof ???
First of all you have to understand that HD7970 did NOT require all the bandwidth that it has. It does need more than HD6970, especially for compute, but it does not strictly need as much as it has. AMD did not have any other option than going 384 bits, because GDDR5 speeds higher than 1400 Mhz are not very doable and are very very expensive anyway. So their only option was a wider bus.
Now:
Evidence #1
192 bit GTX460 has 86 GB/s BW
256 bit 460 has 115 GB/s, that's 33% more BW but performance difference is not much bigger than 5%.
Another example, GTX 480 vs GTX 570, evidence #2
GTX 480 has 177 GB/s
GTX 570 has 152 GB/s - it is slightly faster, despite the 480 having 16% more memory bandwidth.
So is HD7970 kind of performance posible with HD6970 kind of bandwidth? Absolutely.
PS: The HD5670 example you posted, GDDR5 vs GDDR3, you are talking about half the bandwidth which is not going to be the case with GK104 at all (if it really is 256 bit anyway). We would be talking about a 50% reduction is buss width, but an increase of 40% in clocks, for a net bandwidth loss of 10% compared to the GTX580, a card itself is probably NOT limited by it's memory bandwidth anyway.
3dm11 score of my GTX580@850 and stock BW
3dmark.com/3dm11/2588707
GTX580@850 and HD6970 BW ( 1835 mem clocks )
3dmark.com/3dm11/2588751
nuff said ??? ;)
ps. i know that in order to bring GTX580 to HD7970 level in 3dm11, i have to push my 580 almost 1000 core clock but 850 core is enough for proving. :)
this is one of the most civil kept discussions about that topic i have seen in a long time...
people are actually discussing and speculating without any name calling or anything...
and yes, it's a damn graphics card, which is being discussed on a tech enthusiast website...what are we supposed to do? talk about donuts?
you sir, are the one who is trying to cause some stir...so either contribute, or get lost...
Besides the fact that 3% is thin air, we are not talking about making a card like yours be as fast as HD7970 and what memory bandwidth it needs for that. Things don't work like that. AMD/Nvidia spend months designing and balancing out their architectures and chips to get the most out of them and tweaking internal latencies and such. You taking your card and absolutely destroying that balance with a 10% core overclock and 10% memory underclock means nothing. But please, by all means try again.
EDIT: At least you proved that AMD and Nvidia do their job and don't just ramdomly choose the specs of cards, but then again looking at how the only difference is 3% maybe you proved the opposite. I just can't choose what you proved yet. In general nothing, other than a GTX580 at 850 Mhz...
And to finish. You artificially created a 20% deficit in memory bandwidth and the most you obtained was 3% less performance. Bravo, because like I said earlier Nvidia could create a card with only a 10% deficit, so 1.5% slower? Aww man, horrible bottleneck. AWWWWW!
/sarcasm
my GTX580 is not even close to HD7970, but still it has a bottleneck.
imagine Kepler or HD7970@6970 BW couldn't be any faster than mine and thats not only 3% for sure.
at first, you told me that high end gpus have excessive BW, and thats for gpu computing purpose. then you change your argument and told me Kepler doesn't manage memory bandwidth in the same way as Fermi and SI. what kind of unreliable person you are ??? :confused:
Try proving something ( at least find me some reference that not come from your mouth )
OR stop BS around here !!!
And I don't have to prove anything, since I never actually claimed anything. I said that a bottleneck is not warranted, that there's high chances that a bottleneck won't occur and provided REAL evidence of previous cards NOT being bottleneck. The one who says there's going to be bottleneck is you, and the only proof you could provide is a lameass comparison with 3% difference that could be derived from margin of error in 3DMark scoring system or a cat farting down the street. You are not right. Get over it.
EDIT: bah, I decided to be nice and teach you one or two things. Here: realworldtech.com/page.cfm?ArticleID=RWT042611035931&p=2 Note: both have 2x or 100% more bandwidth that their "starved cousins".
Looks like your proc is chocking your 580 like crazy - my 570 at 800Mhz gets a higher p score and graphics score of within 2%. o.O
This was on my facebook feed, thought others here might like a look. Some un-based claims of Nvidia dominance.
www.maximumpc.com/article/news/longtime_nvidia_critics_says_kepler_clear_winner_against_amds_tahiti_architecture
may be u should "try again" :laugh:
oh, and you said you didn't claim anything ???
what is this ??? :laugh: If i had Kepler IN HANDS and benched it right now, i'm sure u gonna make an excuse like "it's only an engineering sample" anyway. :laugh:
My point: Kepler might not be memory bandwidth limited, just as countless of previous cards that AMD and Nvidia surprised us with, that had much less bandwodth than their predecesor. <-- (stating posibilities/probabilities, without stating or asserting how things are going to be only how they may be == no claim)
Proofs: the article, 8800GTX vs 9800GTX, GTX480 vs GTX570, and several cards in the article and many many other cards before and after.
Your claim: Kepler will be memory bandwidth limited. (stating what it will be == claim)
Proof: NONE.
what you think it's "proof": Your GTX580, which is NOT Kepler by any means or stretch of imagination, suffers a 3% penalty when creating an artificial 15-20% gap between stock/balanced GPU clocks and memory clocks. That's it, every 20% less memory BW, degrades performance by 3% on the GTX580, which is not GK104.
I'm still awaiting your proof. The burden of proof in on your side, as always has and you have ZERO proofs so far. Of course you won't have any proof until Kepler is released, but you'll figure it out. ;)
On the positive side, you are a good troll. Mamma troll is probably proud of you.