680 Quad SLI vs 690 Quad SLI

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NExUS1g

Gawd
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Aug 15, 2004
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When it comes time for me to look at a new system, it's always difficult to find reviews, even on HardOCP, of setups this high end. So what I would like help with is finding reviews comparing a quad 690 setup versus a quad 680 setup.

I don't anticipate much change in the FPS and the highs would most likely be well in excess of 120 FPS. As such, I'm not very interested in seeing max FPS. I'm interested in seeing the lowest FPS to ensure that drops in FPS during busy gaming scenes with high AA, ASF, tessellation, etc. go below 120 FPS as little as possible.

I've posted here a few times previously regarding my builds, and I want to let those few who only put down the cost-to-performance ratio of my questions without contributing to the question are welcome to move on to another thread without leaving a reply. Cost-to-performance ratio is of no concern to me and opinions regarding it will fall on deaf ears. Furthermore, this is not a place for the age-old "your eyes can't see more than 60 FPS so it doesn't matter" debate. I notice a significant difference between 120 FPS and 60 FPS, and that's all that needs to be said -- placebo or not.
 
I feel your pain @ 60 vs 120 FPS.

People don't have the right to judge about it being visible or not before having worked with a 120hz screen for a while.
 
Stayfr0sty said:
Well you would get more VRAM usage with the 690s.
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Do you? I was thinking that it still works by mirroring each GPUs memory (2 GB per GPU) so 2 GB total effective memory. If I'm mistaken in that, could you provide a citation for me?
 
Is it possible that he means that the 690's are more efficient with its usage of Vram?..........just sayin'
 
Are you planning water or air cooling? If water, I would go with 4x 680's since you won't have to worry about them suffocating because of close proximity to each other, and might have more overclocking headroom plus the ability to choose between 2 and 4GB models and non-reference PCB's.

On air, I would say the 690's would be better, saving you some slots and leaving space for the cards to breathe.
 
NExUS1g said:
Do you? I was thinking that it still works by mirroring each GPUs memory (2 GB per GPU) so 2 GB total effective memory. If I'm mistaken in that, could you provide a citation for me?
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dboythagr8 said:
Huh? This is false.

You get the same VRAM usage whether you go with a 690 or 2x 680s. Same if you go the Quad SLI route if we're talking about the standard 680s....
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Skillz said:
False information.
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Never mind I thought the 690 had more RAM then a 680, they both have 4 gbs. my bad
 
Stayfr0sty said:
Never mind I thought the 690 had more RAM then a 680, they both have 4 gbs. my bad
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Wrong again. They both have 2GB (per GPU).

---

@OP

-> GTX 690 consume less power, but...
-> GTX 680 have 4GB versions

I know I would choose the 4GB (GTX 680) cards, no matter what the short sighted fools might say.
 
I'm interested in this as well, my understanding is the 690 has less power draw than 2 680s, but also lower clock speeds. So i wonder if fully overclocked which would-be the better choice.
 
All being equal, I would focus more on just the physical hardware side of things.

Honestly, overall the hardware is pretty equal.

690 = two slots and 4 connections to the PSU.
680 = four slots and 8 connections to the PSU.

If you watercool, well I'd get a headache with 4 waterblocks.....:eek:

I had three HD 6950s then bought a 6990 and kept a single 6950 for Crossfire......second setup was much simpler and a shade faster.:)
 
Raudulfr said:
Wrong again. They both have 2GB (per GPU).

---

@OP

-> GTX 690 consume less power, but...
-> GTX 680 have 4GB versions

I know I would choose the 4GB (GTX 680) cards, no matter what the short sighted fools might say.
Click to expand...

I meant total, its 2 gb per GPU on the 690 but all of it gets used.
If you SLI 680s only one of the cards VRAM is used.
 
Stayfr0sty said:
I meant total, its 2 gb per GPU on the 690 but all of it gets used.
If you SLI 680s only one of the cards VRAM is used.
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This is totally wrong. The second 680 get the ram mirrored, this effectively would give the GTX 680 SLI a 512-bit bus of 2gb vram which doubles the memory bandwidth. The ram feeds the GPUs of the 690 and the 680 the same way. Nothing is wasted at all.
 
novadaemon said:
This is totally wrong. The second 680 get the ram mirrored, this effectively would give the GTX 680 SLI a 512-bit bus of 2gb vram which doubles the memory bandwidth. The ram feeds the GPUs of the 690 and the 680 the same way. Nothing is wasted at all.
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Im not talking about bandwith.....
Im saying that isnt the vram mirrored? In other words you put 4x 680s in there that each have 4 gb of RAM per card you only gonna get usuable 4gb not 16 gb.
 
cannondale06 said:
the SAME amount of vram will be usable with either setup.

690=2gb of usable vram
680=2gb of usable vram
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Unless he bought four of the 4GB GTX 680's that eVGA has out. That would about the only way around the 2GB limit of usable vRAM in Quad-SLI. Then if the OP did that he would be back to eight slots being used, eight PSU connectors, more heat, etc. If it were me, I'd go with two GTX 690's. Then again, if OP did any water cooling he could cut it down to using four slots, and less heat build-up in the case.
 
True, but going the wc route, would it be better to have a dedicated loop just for the gpus or ok to out in 1 loop?
 
gflgs said:
True, but going the wc route, would it be better to have a dedicated loop just for the gpus or ok to out in 1 loop?
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If it were two GTX 690's I would think loop would be fine. Four 680's and I personally would look at a dedicated loop.
 
OP, I would assume (I haven't seen any benchies to prove it), that two 690s would be better than four 680s. You'd only have to worry about heat disappation of two cards versus four. The only thing that might hold you back is price (I don't know if 690s command a price premium over their multiple 680 counterparts). Since I'm taking a brief break from work, I can't really go and check the prices, but I trust you'll be able to. I would also assume that driver compatability should be about the same between the two setups, since you're still inherently dealing with four GPU's. Hope this helps. I would assume any issues with quad-SLI would occur on both platforms.

EDIT: And about the 60fps vs 120fps. I also feel your pain. Back in the day on Halo PC, I'd drop my resolution to 800x600 on my Radeon 9700pro, and turn down the settings just so that I could hit 120fps on my old CRT monitor. Yes, there's definitely a perceptible difference. Cheers!
 
jbltecnicspro said:
OP, I would assume (I haven't seen any benchies to prove it), that two 690s would be better than four 680s. You'd only have to worry about heat disappation of two cards versus four. The only thing that might hold you back is price (I don't know if 690s command a price premium over their multiple 680 counterparts). Since I'm taking a brief break from work, I can't really go and check the prices, but I trust you'll be able to. I would also assume that driver compatability should be about the same between the two setups, since you're still inherently dealing with four GPU's. Hope this helps. I would assume any issues with quad-SLI would occur on both platforms.

EDIT: And about the 60fps vs 120fps. I also feel your pain. Back in the day on Halo PC, I'd drop my resolution to 800x600 on my Radeon 9700pro, and turn down the settings just so that I could hit 120fps on my old CRT monitor. Yes, there's definitely a perceptible difference. Cheers!
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Thanks for your ideas, and thanks for getting the thread back on topic.
 
NExUS1g said:
Thanks for your ideas, and thanks for getting the thread back on topic.
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You're very welcome. I forgot to say that if I had the money to spend on this kind of setup, I'd sway toward the two 690's myself. It does look like there is a price premium for the 690 (not too bad though, at most it's a hundred bucks) over two 680s. That and Newegg doesn't have any in stock. So on a practical level, you might look at getting a 680, unless you want to wait on stock.
 
TR noted that the 690 was faster than two 680s when it came to average frame-times while putting out the same frame-rate; essentially, it was measurably smoother, though not noticeably.

If you double the GPUs in each case, and use an X79 board that can has two 16x PCIe 3.0 slots, that advantage might translate and possibly be noticeable.

You'd also need to test with 3x1080p@120Hz to really tell. Anything less would make isolating the GPUs hard, and anything more would bump into the VRAM limit.
 
Stayfr0sty said:
Im not talking about bandwith.....
Im saying that isnt the vram mirrored? In other words you put 4x 680s in there that each have 4 gb of RAM per card you only gonna get usuable 4gb not 16 gb.
Click to expand...

The vram is mirrored so that you effecively have 2gb on a 512-bit bus. With a 4gb (they are advertised as 4gb) 6990 it's the same situation. 2gb of mirroed vram on a 512-bit effective bus. My issue was with the statement "If you SLI 680s only one of the cards VRAM is used. " Which is not true. All the vram is used, its just used differently. Instead of providing a total of 4gb, It provides 2gb of double speed memory, but one card's ram doesnt sit there and do nothing. It's working, too.
 
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