[H] NVIDIA GeForce GTX 980 SLI 4K Video Card Review

[96Firebird]

@amenx No its a special situation where the traditional and out-dated SLI bridge just lacks bandwidth to cope with 4K resolution, the stutters, frame latency spikes or dropped frames does not happen (no where near as bad) on lower resolution.

It's worse in the 780 ti, so its not immature drivers.

What is the maximum bandwidth of the SLI bridge?

 

[Keysplayr]

NV has time to improve their drivers before 390/390X launch. If not, they will just use GM200 to compete. As long as their customer base is willing to pay $550 for a 980 they have little reason to lift a finger. Even when NV's driver's don't work well until an SLI/driver fix, NV users tend brush their issues aside mostly. A lot of 780/780ti SLI owners decide to hold off on upgrading to 970/980 which seems like a smart idea at this time.

It was expected that 780/780Ti owners would stay put though. 970/980 is really for 680/770/280/280X and below owners who would benefit from the performance gain.

"NV users tend brush their issues aside mostly."
Heh. I'd like to see the study data for this conclusion.

 

[KaRLiToS]

It was expected that 780/780Ti owners would stay put though. 970/980 is really for 680/770/280/280X and below owners who would benefit from the performance gain.

It was expected also for Titan Black users.

NV users tend brush their issues aside mostly."
Heh. I'd like to see the study data from this conclusion.

You don't need a study for that. It's mostly an observation over the past years, they tend to protect their ego.

It's better not to talk about their card issues but the competition one.

 

[Silverforce11]

What is the maximum bandwidth of the SLI bridge?

Nowhere near XDMA.

The point is it's not just bad drivers, as the problem occurs on Kepler and that's been around for awhile now.

 

[RussianSensation]

It was expected that 780/780Ti owners would stay put though. 970/980 is really for 680/770/280/280X and below owners who would benefit from the performance gain.

When 7970 came out, it was ridiculed for being one of the smallest jumps in absolutely performance in NV/AMD's history despite delivering 25% more performance at stock and 40-80% higher performance against 580 OC vs. OC. When 980 came out, it was literally the worst performance increase of all time, 5-10% stock vs. stock 780Ti and maybe 15-20% against a poorly overclockable 780Ti. Against a good overclocking 780Ti, the 980 can't even win. Did 980 get the same ridicule despite some models selling for $580-630?

980 is one of the worst overpriced GPUs from NV in recent history, along the likes of $650 280, $650 780, $700 780Ti and $1000 Titan. Without 970, this is the worst launch ever for an x80 level card. Even Fermi was better since at least an overclocked 480 was way faster than a 285.

"NV users tend brush their issues aside mostly."
Heh. I'd like to see the study data for this conclusion.

They brush aside poor performance in less popular games not followed on forums like AAA/GW titles:
http://gamegpu.ru/action-/-fps-/-tps/the-vanishing-of-ethan-carter-test-gpu.html

Since not everyone only plays AAA/most popular games, this is pretty important to some. Also, you often read comments from NV GPU owners how AMD drivers are crap but they haven't used an AMD/ATI card in 5-10 years. How often do you read thread-crapping of "NV drivers suck"?

 

[RussianSensation]

Nowhere near XDMA.

The point is it's not just bad drivers, as the problem occurs on Kepler and that's been around for awhile now.

I think I disagree with HardOCP's conclusion that XDMA vs. SLI is the culprit. 4K for NV has been a sore point for a long time now, and it's probably more related to their 4K SLI drivers and some hardware bottleneck.

Even 280X CF trades blows with Titan Z / 780 SLI at 4K in some games.

If XDMA was the primary factor, 280X wouldn't' be that close at 4K. 970 SLI's advantage at 1080p/1440p fades away against 290s once at 4K despite 970 having 64 ROPs like the 290s. If you look at 290X vs. 780Ti single benches, 780TI is pretty fast but falls off in SLI. CF driver scaling is simply better than SLI in recent years and it only gets worse for NV once you add 3rd and 4th GPUs.

Look at Bioshock Infinite where NV has won historically (780Ti, Titan Black > 290X) but the minute you are comparing SLI vs. CF, 290Xs win.

Anyone who has followed 4K benches would have known that for the last 11 month 290X CF > 780TI SLI and NV needed 980s to catch up and barely surpass 290Xs. Once 390X comes out, 980 SLI will not be competitive for 4K/multi-monitor gaming. NV will have GM200 to respond and use price drops on 970/980 to capture the key 1080P/1440p and below markets. With AMD already on 64 ROPs, they need to just focus on adding as many stream processors and texture mapping units as possible, while doubling their geometry performance - their biggest bottlenecks now.

 

[wand3r3r]

I would suspect that XDMA isn't the sole cause of the much better scaling and strong performance at 4k, I think it was a big help in smoothing out crossfire to become the new standard for smooth dual cards especially combined with mantle. I would venture a guess the choppy and weak SLI are more due to the architecture and details like 256 bit bus vs. 512 bit bus and the GPU die internal architecture. NV simply works better at lower resolutions, whereas AMD works better at higher resolutions. Keep in mind we are comparing last gen high end with this gen mid range. Had the 980 been a 970 instead with a lower price closer to the historic mid range part, it would be much more impressive. Big maxwell and 390x will determine the next couple years of 4k performance and will be much more interesting. The main take away here is that the 980 has some serious weaknesses, high resolution and price, whereas the 290x has efficiency but otherwise was an excellent future proof architecture. @Keysplayer where are all of the smoother but slower campaigners now? I'd say the NV fans have lots of patience when it comes to "their" brand having issues. Not that AMD is perfect, far from it.

 

[Erenhardt]

What is the maximum bandwidth of the SLI bridge?

Its the maximum amount of data that can be transferred through the multiple Nvidia GPU connector designed for communication between two graphics cards in a single unit of time.
http://en.wikipedia.org/wiki/Bandwidth_(computing)
http://en.wikipedia.org/wiki/Bit_rate

 

[96Firebird]

Its the maximum amount of data that can be transferred through the multiple Nvidia GPU connector designed for communication between two graphics cards in a single unit of time.
http://en.wikipedia.org/wiki/Bandwidth_(computing)
http://en.wikipedia.org/wiki/Bit_rate

Looking for numbers. Go!

 

[iiiankiii]

It's a good thing 4k is bleeding edge stuff. I would expect problems with it. At this point, 4k just isn't ready for primetime. If you must do 4k, it looks like AMD is the better solution right now for smooth game play.

 

[Silverforce11]

It's a good thing 4k is bleeding edge stuff. I would expect problems with it. At this point, 4k just isn't ready for primetime. If you must do 4k, it looks like AMD is the better solution right now for smooth game play.

What do you mean its not ready for prime time?

Decent 60hz 4K monitors are cheap now. I like IPS (its better) but it's certainly not $2,000 better.

 

[Erenhardt]

Looking for numbers. Go!

There is an old interview with SLI marketeer which mentions 1GB/sec. Quite insignificant...
http://www.penstarsys.com/editor/tech/graphics/nvidia/sli_inter/

 

[MeldarthX]

Seriously 96; two seconds to do a search on it.

http://www.geforce.co.uk/hardware/technology/sli/faq
The SLI connector is a proprietary link between GPUs that transmits synchronization, display, and pixel data. The SLI connector enables inter-GPU communication of up to 1GB/s, consuming no bandwidth over the PCI Express bus.

That is the limiting factor; until they lose the bridge; they will be held back....

 

[realibrad]

Seriously 96; two seconds to do a search on it.

http://www.geforce.co.uk/hardware/technology/sli/faq
The SLI connector is a proprietary link between GPUs that transmits synchronization, display, and pixel data. The SLI connector enables inter-GPU communication of up to 1GB/s, consuming no bandwidth over the PCI Express bus.

That is the limiting factor; until they lose the bridge; they will be held back....

That is "A" limiting factor. As Russian pointed out, the 280x still uses a bridge.

 

[njdevilsfan87]

I've felt like AMD has always performed better on the high resolutions. When it was the 7970 vs 680, the 680 beat the 7970 at 1080p or less. Then GK110 came around and NV was good up to 1600p (or even 1440p wide now). But when you go higher, AMD once again wins. Once NV gets 4K down, I'm sure AMD will be winning at 8K.

 

[96Firebird]

There is an old interview with SLI marketeer which mentions 1GB/sec. Quite insignificant...
http://www.penstarsys.com/editor/tech/graphics/nvidia/sli_inter/

Thanks!

So a 4K image is 3840x2160, ~8.3MB, assuming no compression. 1024MB/s/8.3MB = 123Hz. So the bandwidth should be enough for 4K @ 123Hz, assuming the image travels one way only. Using AFR, the image from the second card is every other screen image. So does that mean the SLI bridge has enough bandwidth for 4K @ 246Hz at the display?

Sorry, don't let numbers get in the way of guesswork!

 

[Silverforce11]

So a 4K image is 3840x2160, ~8.3MB, assuming no compression.

You forgot the 32 bit color w/ alpha information.

That's 3840 x 2160 x 4(!) = ~32MB.

AMD have stated the main reason for moving to XDMA was to get significantly more bandwidth to get good 4K CF.

http://community.amd.com/community/.../01/03/modernizing-multi-gpu-gaming-with-xdma

@RS I've seen other reviews and its extremely rare for CF 7970/R280X to rival 780/ti SLI or Titan Z. Perhaps its a one off with that review? :/

 

[96Firebird]

If the 4K image is ~32MB, how do they get over 60FPS in any benchmark?

 

[KaRLiToS]

If the 4K image is ~32MB, how do they get over 60FPS in any benchmark?

There is still some traffic over the Pcie lanes.

 

[Silverforce11]

If the 4K image is ~32MB, how do they get over 60FPS in any benchmark?

Because you assumed no compression.

I don't know the full details to the inner workings of CF/SLI. I just know textures existing in GPU memory, occupy a heck of a lot of data when the resolution is high due to the square nature & color information.

Then there's also the matter of runt frames, as explored in recent times. You think its 80 fps but in actual reality its 50. etc

 

[RussianSensation]

What do you mean its not ready for prime time?

Decent 60hz 4K monitors are cheap now. I like IPS (its better) but it's certainly not $2,000 better.

$1,000 for 32" IPS. This BenQ 32" IPS monitor linked below has just wiped out all reasons to buy 2560x1600 30 inch displays and soon 27-30 inch versions will creep below $1000 mark.
http://www.bhphotovideo.com/c/produc...0_uhd_ips.html

I have a feeling 4K IPS displays will drop a lot in the next 2 years so NV and AMD better be preparing for this shift with massive GPU performance increases. I am thinking my next monitor upgrade will be 4K and IPS. I am probably going to skip 1440p and 1600p. Boy I am setting myself up for expensive GPU upgrades down the line

NV is supposed to incorporate NV Link into Pascal, and this should far surpass the PCIe 4.0 bandwidth AMD will have at its disposal. Having said that I doubt that PCIe 4.0 will be bottleneck for GPU bandwidth for 5+ years. In 2016-2017 with Pascal, NV should be far ahead of AMD in terms of theoretical bandwidth (I believe NV Link is 192GB/sec) which is when I expect NV to start marketing 3-way and 4-way SLI more aggressively.

 

[3DVagabond]

I would suspect that XDMA isn't the sole cause of the much better scaling and strong performance at 4k, I think it was a big help in smoothing out crossfire to become the new standard for smooth dual cards especially combined with mantle. I would venture a guess the choppy and weak SLI are more due to the architecture and details like 256 bit bus vs. 512 bit bus and the GPU die internal architecture. NV simply works better at lower resolutions, whereas AMD works better at higher resolutions. Keep in mind we are comparing last gen high end with this gen mid range. Had the 980 been a 970 instead with a lower price closer to the historic mid range part, it would be much more impressive. Big maxwell and 390x will determine the next couple years of 4k performance and will be much more interesting. The main take away here is that the 980 has some serious weaknesses, high resolution and price, whereas the 290x has efficiency but otherwise was an excellent future proof architecture. @Keysplayer where are all of the smoother but slower campaigners now? I'd say the NV fans have lots of patience when it comes to "their" brand having issues. Not that AMD is perfect, far from it.

I agree. I think the advantage @4K, is just an extension of AMD's advantage at higher resolutions in general. This has been going on for a while and simply glossed over. People prefer to show 1080 benchmarks to show nVidia's superiority in "CPU bottlenecked" situations. These same people often have no use for Mantle, which is far superior in relieving CPU bottleneck. It seems in GPU limited situations, nVidia has nothing but lower power usage and higher prices. The 980 is almost twice as expensive as the 290X right now, but people still recommend it/make excuses for it.

While I like more efficient and understand the importance of it (it should save you money), it's not an end all be all. Especially at a huge price premium that negates most of it's advantages.

 

[Keysplayr]

It was expected also for Titan Black users.





You don't need a study for that. It's mostly an observation over the past years, they tend to protect their ego.

It's better not to talk about their card issues but the competition one.

Yes, Titan and Titan Black as well.

And as for the second and third sentences. Here ya go ---->

 

[KaRLiToS]

Yes, Titan and Titan Black as well.

And as for the second and third sentences. Here ya go ---->

hehehe :thumbsup::thumbsup:

I don't think you could have phrase it better.

 

[jackstar7]

Interestingly, TD has a 295x2 going for $900 (and 3 games) right now. So in very niche cases, it would almost qualify as a value.

http://www.tigerdirect.com/applicati...046&CatId=7387
(also available via Amazon from TD... because commerce)