i7 3820 not overclocked could bottleneck 680 gtx Sli?

[Grooveriding]

Will bottleneck you in plenty of games, most notably will be Battlefield 3. World of Warcraft would be another, but not by holding back your cards, some games just perform better the faster you clock your CPU.

Some games, like the ones I mentioned, just like more CPU power regardless of your GPUs. In other games, like say an older source game - you can be holding back your GPUs with your CPU - but it's irrelevant as it's extra power you don't even need. Just going from 150 to 180 fps. Pointless.

 

[brandon888]

Will bottleneck you in plenty of games, most notably will be Battlefield 3. World of Warcraft would be another, but not by holding back your cards, some games just perform better the faster you clock your CPU.

Some games, like the ones I mentioned, just like more CPU power regardless of your GPUs. In other games, like say an older source game - you can be holding back your GPUs with your CPU - but it's irrelevant as it's extra power you don't even need. Just going from 150 to 180 fps. Pointless.

so it won't be pointless to put 2 680 or 670 on system with not OCed i7 3820 ? because bottleneck will be minor you mean ?

 

[MrK6]

so it won't be pointless to put 2 680 or 670 on system with not OCed i7 3820 ? because bottleneck will be minor you mean ?

It's more relative. The performance of your CPU can be equated to outputting FPS just like your graphics cards. In situations where your graphics card(s) have the power to put out more frames but they can't because they are being held back by the CPU working as fast as it can, you have a bottleneck. Different games will stress the CPU in different ways. Sometimes games, e.g. older ones like the Source ones mentioned, aren't graphically stressful enough on graphics cards and therefore your CPU reaches it's maximum performance ability before your graphics card(s) does. The same happens when you have modern game that really pounds the CPU (BF3 multiplayer, for example), and again the CPU can't feed the graphics card(s) fast enough.

That said, you want to build a system that is balanced so that your graphics cards can always be fed as fast as possible by the CPU. That means buying, and even over-buying, a faster CPU so that the graphics cards are always the limiting factor. I think a stock i7-3820 would leave you SLI GTX 670/680s (again, 670 is probably the better buy) wanting. However, if you get a good motherboard that can overclock the i7-3820 with alternative base clock selection (see: http://www.techspot.com/review/492-intel-core-i7-3820/page9.html ), you could get something respectable in the 4.5GHz+ range which would be fine.

 

[boxleitnerb]

Having the GPUs always perform at maximum capacity is not a necessity, why would it be? I don't get why people complain about that all the time. I don't hear "not all of my 4 cores are fully utilized".

If the CPU is holding the GPU(s) back, there are three possibilities:

a) the fps provided by the CPU are enough for you. Go vsync or fps cap to save power and have the cards run cooler.
b) the fps provided by the CPU are enough for you. Increase graphics quality settings (SSAA etc.). fps stay roughly the same if you don't go overboard with the settings.
c) the fps provided by the CPU are not enough. Upgrade the CPU.

 

[mazeroth]

Any reason why you're limiting yourself to 1080p with SLI'd 680's? What kind of screen do you plan on using?

 

[Jaydip]

Having the GPUs always perform at maximum capacity is not a necessity, why would it be? I don't get why people complain about that all the time. I don't hear "not all of my 4 cores are fully utilized".

If the CPU is holding the GPU(s) back, there are three possibilities:

a) the fps provided by the CPU are enough for you. Go vsync or fps cap to save power and have the cards run cooler.
b) the fps provided by the CPU are enough for you. Increase graphics quality settings (SSAA etc.). fps stay roughly the same if you don't go overboard with the settings.
c) the fps provided by the CPU are not enough. Upgrade the CPU.

Good points box.I think too much hpc talks have addled our minds .Honestly if you are getting good fps this is pointless unless you are a developer hell bent on optimizing your program.

 

[jaredimre]

Any reason why you're limiting yourself to 1080p with SLI'd 680's? What kind of screen do you plan on using?

At the moment I have a Full Hd 60Hz display that can reach 100Hz through motionplus technique...but I don't know if one should trust this 'motionplus' method . Do you think it's real 100Hz?
For that reason, I am going to buy a Full Hd 120Hz display in order to benefit from the 680 SLI high framerate in most games (around 100-120 fps) and enjoy the difference compared to my 60Hz display.

 

[Rvenger]

First off I'd go with 670 SLI. A good 670 will game as well as a 680. Take the money saved and get a 3930. While there aren't very many apps/games that will scale to 12 threads today, there very well could be in a year or two. At that point you'll be happy you bought a 3930 CPU. I don't think you'll ever regret getting the 670's instead of the 680's.

Wow, this :thumbsup:

I have owned 2 GTX 670s and 2 GTX 680s. I did not notice the difference in performance between them and the minimal performance difference can be made up in a small overclock.

 

[brandon888]

on 60 hz monitor i7 3830 with 2 670 is fine ? sure on 120 hz there will be more bottleneck

 

[Annisman*]

Now things are just getting out of hand. A monitor can't be bottlenecked, even though I know what you are trying to say. Let's just not go there.

 

[cob77]

Wow, this :thumbsup:

I have owned 2 GTX 670s and 2 GTX 680s. I did not notice the difference in performance between them and the minimal performance difference can be made up in a small overclock.

Is there a good chance this will change in the near future? Like when the next consoles come out and finally console ports will use the extra power that PC have, do you think there will be a noticeable benefit between owning 670 or 680 sli, then?

 

[BrightCandle]

A pair of 680's can happily be bottlenecked by a 3930k running at 4.5 Ghz. Some games are just plain CPU limited and there isn't a thing you can do about (Planetside 2). However a pair of these babies will almost always be GPU limited at 5760x1200, a stock CPU makes no difference there, except with one game (Arma 2).

I think people worry about CPU/GPU combinations too much, a modern CPU is more than good enough for basically everything and bottlenecks are just way more complicated than the simple "am I going to bottleneck this?". Because the answer is always yes, always. Some parts of the frame are always dominated by the CPU and some are always dominated by the GPU, that is the nature of DirectX. Stop sweating the details, a 3820 will do fine.

I would however say if you are going X79 get the 3930k. If your getting into the platform at least get the benefits with a 6 core chip, on 4 cores you are better off on Z77 unless you need the PCI-E lanes (you don't with 2x680) or lots more RAM than Z77 can handle (which as a gamer you certain don't).