At what clock speed are the CPU bottlenecks removed for these GPU's?

ambam

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I have a Core i7 930 @ 2.8 GHz, 6GB of DDR3 1333 MHz RAM.

At which clock speed is the CPU bottleneck completely removed for the Radeon HD 5870 and 5970, as well as the GTX 480?

I have a ZALMAN CNPS9900 CPU cooler.
 

LePhuronn

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It depends heavily on the resolution you're gaming at - the higher the resolution, the more emphasis is put on the GPU.

I don't think you have any CPU bottleneck issues with the i7 930, although even with that poor Zalman cooler you should look at bumping up to 3.2GHz simply because you can so easily.
 

ambam

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It's certainly a heck of a lot better than the stock Intel cooler.
 

hundredislandsboy

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It will be never be removed. Just check the default scores for 3DMark06, Vantage, even almost 10 year old Aquamark3 benchmarks. What I mean is, they are able to raise the scores and framerates when the CPU go past 4 Ghz, 4.5 Ghz, 5 Ghz and beyond on LN2 cooling. Those GPUs will keep giving more at 6 and 7 Ghz provided the CPU can go faster and faster.





 

LePhuronn

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At the end of the day it just comes down to your frame rate. The monster graphics set-ups you're talking about will handle pretty much anything at any resolution when paired with a good processor.

Otherwise it's a balance between CPU, GPU and playing resolution to get the best frame rates as you can. We can only advise on that when we know exactly what you're going to run.
 

ambam

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Mostly Crysis and Crysis Warhead on very high/enthusiast on 1024x768 0x AA and motion blur disabled. Most of today's top-end graphics cards can run any game on maximum detail, it's just AA and extremely high resolutions that kills performance. High resolution is not the difference between night and day like many people say it is. It can make the difference between an enjoyable gaming experience, and an extremely slow, unplayable one.

Apparently, if you can max Crysis, you will be able to max Crysis 2 due to the many optimizations and flawless coding of the CryEngine 3 which the CryEngine 2 did not have.

A single HD 5870 or GTX 480 are overkill for those games on that low resolution, as I've been told. It's 1920x1080 and beyond, combined with anti-aliasing which really gives graphics cards a run for their money.

The only GPU setups which can fully max Crysis (playably) are Two superclocked HD 5970's in xfire, and 3-4 way GTX 480's in SLI.
 

ksampanna

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The only GPU setups which can fully max Crysis (playably) are Two superclocked HD 5970's in xfire, and 3-4 way GTX 480's in SLI.

I assume you're talking @ 1900 X 1200. Well then, you might want to add the 5870, the 4870X2 (old but still packs a punch) & the gtx 295.
And if you think 25-30 fps is playable, then the 470 & 5850 do work well.
 

MARSOC_Operator

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With 2x5970 or 3x480 you will ALWAYS have a CPU bottleneck, it doesn't matter if it's an i7 hexacore at 4.0+Ghz.
 

ambam

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I wonder how the 6-8 core "sandy bridge" Intel processors will handle bottlenecks.
 

LePhuronn

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About the same as existing CPUs I should imagine - unless their stock speeds go over 4GHz I don't see anything changing until games are multi-threaded, and then existing Nehalem chips will do the job better than they do now.
 

ambam

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Bottlenecks in most cases are a bit exaggerated IMHO. A Core i7 even at stock speeds, will handle pretty much any GPU setup without any noticeable performance issues in the fps areas. But if you tried running a GTX 295 or HD 5970 on a Pentium 4, the true abilities of those cards will be SEVERELY limited by that slow processor.
 

hundredislandsboy

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The OP isn't looking for performace issues that canbe "noticed." It's a simple question whether a bottleneck exists at certain CPU speeds. Although a stock i7 might provide smooth framerates, the fact remains that today's top of the line GPUs don't get "maxed out" "the pedal to the metal" until LN2 comes into play and pushes the CPUs past 5 Ghz.

To create even faster and wider bandwidth, designing future CPUs should focus more on architecture and not just GHz speed since you can't change the physics of friction and heat but you can change the number of lanes and pathways to be added to new CPUs.
 

ambam

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What is LN2?
 

LePhuronn

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Liquid Nitrogen




In which case then, the question's been answered - the ridiculous multi-GPU setups the OP has listed will always be bottlenecked by the CPU unless you break out the extreme cooling and overclock to Hell and back, so yes a Core i7 930 will hold back all GPUs listed in the initial question.

Unless you enable AA at ultra-high resolutions and bring the GPUs to their knees.


Is there really now anything else to say?
 

hundredislandsboy

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Yes. Has anyone hooked up a GTX 480 or HD 5970 to a quad-socket motherboard (w/ 4 OC'd CPUs) and forced it to run benchmarks? Is the CPU bottleneck the same os does the GPU become the bottleneck?

 

ambam

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How are you supposed to power that?
 

ambam

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Let me get this straight, Four HD 5970's or GTX 480's, in a dual socket LGA1366 motherboard, with Two Ci7 980X's in them?

There are NO ATI or Nvidia drivers for 8-GPU's. There are for a quad-GPU setup though...

That hardware setup would bring even a 1,000W PSU to it's knees. I was thinking about something more along the lines of the PSU listed in the link below.

http://www.engadget.com/2007/01/05/ultra-products-unveils-2000-watt-x3-atx-power-supply/
 

ambam

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Server chips are terrible at running video games and non-network related applications.

Four server CPU's would run Crysis far slower than let's say a Core i7 or Phenom II.