(Tom's) Seven GeForce GTX 660 Ti Cards: Exploring Memory Bandwidth

[Cerb]

The irony is I feel that the GTX 660ti did such a nice job with AA, even with x8 AA, that it's competition and performance helped reduce AMD's pricing. Also felt it was placed in a nice price position with a 299 MSRP HD 7870 and a 349 MSRP HD 7950. The technology pricing landscape changes swiftly.

If those were the prices, it might be better placed. But, they weren't. They might be MSRPs, but nobody outside of the Apple RDF buys based on MSRP. A 7870 prior to the 660 Ti launch could easily be had for under $250, with $250 being typical for reference cooling. You'd have to have been crazy to pay $300 for one, though some existed. $250 is the staring price, including good aftermarket cooling, now, and you still find them for less. The 660 Ti, meanwhile, starts at $300.

Isn't the 660 the card that has unequal bandwidth to the memory chips? 2 x 64 bit controllers to 1GB, and a single 64 bit controller to the other 1GB? I wonder how that may play into it as more of that 1GB with just the single 64 bit connection has to be used.

If the assymetrical layout were the problem, we'd see dips in performance close to as if it had only a 128-bit memory interface--half bandwidth--when the doubled-up channel was being hogged. GPUs have such bandwidth needs, and NV GPUs have so much SMT, that they should be able to hide the access penalties, as long as they can make sure no sets of whole large data structures are mostly in the doubled-up channel. So far, it has worked out, as well.

The GTX 460, 550, 560, and now 660, hit bandwidth/ROP limits, with no funky cases of really poor bandwidth. Slicing the memory up every few, or tens, of KB, so that the doubled channel got what would have gone to the 4th channel on higher cards, would probably be enough, though I'm sure they had some corner cases to work out (IE, virtual 1,2,3,4 -> real 1,2,3A,3B, at a small enough granularity that important data always rolls over to other channels, maybe some special rules for often-accessed buffers and such).

 

[Grooveriding]

It has nothing to do with me "defending" my card or anything of that sort. We are discussing memory bandwidth in this thread, right? What do you think impacts MSAA and high resolution gaming? Memory bandwidth, ROPs and texture performance. Kepler has good texture and ROP performance so that can't be the answer.

So? You have an alternative theory? Why do NV cards perform so much worse at 1440/1600P and with higher MSAA levels than they do at 1080P with FXAA or no AA/minimal AA?

Skyrim with MSAA - http://www.computerbase.de/artikel/grafikkarten/2012/test-amd-radeon-hd-7950-mit-925-mhz/19/

HD7950 V2 vs. 670

1080P 0AA = +10%
1080P 4AA = +13%
1080P 8AA = +19%

1600P 0AA = +20%
1600P 4AA = +17%
1600P 8AA = +22%

Looks to me generally the higher MSAA you use and the more you increase resolution, the slower GTX670/680 cards gets. That would explain why 660 would not do that well against 7870 with MSAA and why 660Ti would have trouble beating 7950 after-market cards with MSAA enabled.

Should of just ignored that. Didn't like the facts, resorted to a cheap shot rather than accepting the numbers. I was surprised myself to see the difference AMD has made with drivers. They would of been better served to of had those improvements earlier, but better late than never. No idea what is going on with nvidia and drivers lately, months without releases and long stretches with major games not seeing SLI profiles; Alan Wake, Sleeping Dogs etc. And now there is no working SLI in Guild Wars 2.

You used to be able to hit their forums and try to get some sort of response, but nvidia's forums have been down for months since they got hacked.

 

[VulgarDisplay]

I don't disagree with Kepler's current bandwidth issues. I'm just saying, as I have been for about the last eight weeks now, 8x MSAA is about the dumbest graphical improvement to enable per the performance hit and lack of noticeable image quality improvement.

Personally I think benchmarking with 8xMSAA is a good way to see what kind of performance you can expect from a GPU once the new console cycle starts. The new consoles should see games having a vast improvement texture quality and the amount of memory games are actually using.

GCN appears more future proof at this time but who's to say that the next generation of games will be playable on the 7xxx series AMD cards? Also, nvidia can easily improve their performance in this aspect with a refresh. Only time will tell, but I honestly think these high memory benchmarks will simulate what we will be seeing a year or so from now in games

 

[maddie]

It was tongue in cheek. You can't deal with it, I suggest counseling.
Are we done? No, of course we aren't. PM me if you want to rip each other apart.

Your card is awesome Russian. Don't ever let anyone tell you different.

There are many here who are passionate about their preferred card/graphics manufacturer, but I get the impression that you are very calculated in your postings to discredit AMD at all costs even if you KNOW your statements to be untrue.
For every poster here, many others only read the forums and a novice might be mislead by you.
I consider that a great disservice.

 

[LOL_Wut_Axel]

Still not sure why anyone would buy this card. The HD 7870 is $250 and the HD 7950 $300...

 

[Rvenger]

Still not sure why anyone would buy this card. The HD 7870 is $250 and the HD 7950 $300...

ftfy

 

[RussianSensation]

Sapphire Dual-X 7950 for $280 on Newegg.

Life is getting real tough for the 660Ti and even 660s. NV's AIBs are asking $240-250 for after-market 660s. Wow, $30-40 more and you have GTX680 level of performance at your fingertips at 1050mhz HD7950 GPU overclock.

 

[Face2Face]

Sapphire Dual-X 7950 for $280 on Newegg.

Life is getting real tough for the 660Ti and even 660s. NV's AIBs are asking $240-250 for after-market 660s. Wow, $30-40 more and you have GTX680 level of performance at your fingertips at 1050mhz HD7950 GPU overclock.

So a 7950@ 1050 is equal to a GTX 680? I get stable 1050/1575 with stock volts .0971

 

[SirPauly]

If life is getting real tough, one may imagine, there may be price adjustments.

 

[Cerb]

If life is getting real tough, one may imagine, there may be price adjustments.

To me, life getting real tough looks a lot like people going, "drop the price so I can buy it, already! I know you're going to have to do it, so I'm not buying it until it's lower! I don't want AMD, so please hurry up!"

 

[cplusplus]

GCN appears more future proof at this time but who's to say that the next generation of games will be playable on the 7xxx series AMD cards? Also, nvidia can easily improve their performance in this aspect with a refresh. Only time will tell, but I honestly think these high memory benchmarks will simulate what we will be seeing a year or so from now in games

Well, if AMD manages to get some type of GCN card into the next Xbox and Playstation (and remember that they have the contracts for both, the question is just whether they can create something using GCN at the right price and right performance/power level by early to middle of next year), that in and of itself would help the 7xxx series be able to run the next level of console ports well for a long time.

 

[3DVagabond]

To me, life getting real tough looks a lot like people going, "drop the price so I can buy it, already! I know you're going to have to do it, so I'm not buying it until it's lower! I don't want AMD, so please hurry up!"

You really think that's what someone with a 7970 running 1150/1700 is saying

 

[Cerb]

You really think that's what someone with a 7970 running 1150/1700 is saying

No, I think that someone with a 7970 isn't worried about it. I think that's somewhere along the lines of thought of someone wanting to upgrade to a $200+ Geforce might be thinking, because it's a bit too expensive, right now.

 

[3DVagabond]

Sapphire Dual-X 7950 for $280 on Newegg.

Life is getting real tough for the 660Ti and even 660s. NV's AIBs are asking $240-250 for after-market 660s. Wow, $30-40 more and you have GTX680 level of performance at your fingertips at 1050mhz HD7950 GPU overclock.

No, I think that someone with a 7970 isn't worried about it. I think that's somewhere along the lines of thought of someone wanting to upgrade to a $200+ Geforce might be thinking, because it's a bit too expensive, right now.

Well, maybe you didn't see where the quote came from that you said. "To me, life getting real tough looks a lot like people going, "drop the price so I can buy it, already!" Because it was by someone who does own that O/C'd 7970 I was referring to. So it obviously isn't what it means at all. It means that nVidia is behind on price/performance.

 

[Cerb]

Well, maybe you didn't see where the quote came from that you said. "To me, life getting real tough looks a lot like people going, "drop the price so I can buy it, already!" Because it was by someone who does own that O/C'd 7970 I was referring to. So it obviously isn't what it means at all. It means that nVidia is behind on price/performance.

'Behind on price/performance' and 'drop the price' don't go together. At all.

It's not a GTX 470. It's just a bit too expensive. Thus, "there may be price adjustments."

If you are a fanboy, use their 3D monitor tech, play several GPU-accelerated PhysX games, etc., sitting on the edge of your seat and waiting for the prices to drop would be your best bet, since the 670 doesn't need to drop that much [yet], and there's not much good from NV right now near $200-250.

 

[SirPauly]

Sure there is; it's called the GTX 660.

http://www.techpowerup.com/reviews/ASUS/GeForce_GTX_660_Direct_Cu_II/29.html