I7 3960x Bottleneck?

[dbhelman]

Hello. I've been researching for a new build. I think I'm gonna wait til April for Kepler and IB, but am still considering SB. Why does this test consider their i7 not able to handle some of the GPU setups and it being a bottleneck?

link http://www.tomshardware.com/reviews/radeon-hd-7950-overclock-crossfire-benchmark,3123-4.html

I always read about how most games aren't limited by the CPU. Thank you.

 

[HEXiT]

there is no current cards out at the moment and probably for the next few years that will bottleneck an i7 SB...

 

[rolli59]

When you look at benchmarks for CPU performance in games and many of the CPU's, with same GPU, show the same fps then that is an indication that the GPU has reached its limit. On the other hand when you see that you got improvement with better CPU's still using the same GPU then the CPU is the limiting factor!

 

[dbhelman]

Agreed. Did I read the article wrong? Sorry the link didn't post correctly. I understand that pcie3 won't be useful for a while and that some games/software don't make effienct use of cpu vs gpu power.

 

[dummos]

pci 3.0 wont become useful until ivy bridge an no theres not a card set up you can throw at a sandy bridge that will bottleneck it

 

[cbrunnem]

there is no current cards out at the moment and probably for the next few years that will bottleneck an i7 SB...

dual 7970s prolly would bottleneck a stock sb i7 in some games.

 

[dbhelman]

That's how I read the review. It said the i7 wasn't quite enough processing power for some of the dual and quad gpu setups in some games. It specifically mentioned it about skyrim and also said something about the software design being optimized for consoles.

 

[amuffin]

software design being optimized for consoles.

That is where we are being screwed

 

[dbhelman]

From:
http://www.tomshardware.com/reviews/radeon-hd-7950-overclock-crossfire-benchmark,3123-8.html

Even at 4.2 GHz, our Core i7-3960X is the primary bottleneck at 1680x1050 and 1920x1080.

 

[dbhelman]

From:
http://www.tomshardware.com/reviews/radeon-hd-7950-overclock-crossfire-benchmark,3123-4.html

We've transitioned our test platform for graphics to a Sandy Bridge-E-based Core i7-3960X overclocked to 4.2 GHz. You'll notice that, in some cases, that's still not enough processing power to let some of our more demanding two- and four-GPU configurations really stretch their legs.

 

[jimmysmitty]

From:
http://www.tomshardware.com/reviews/radeon-hd-7950-overclock-crossfire-benchmark,3123-8.html

Even at 4.2 GHz, our Core i7-3960X is the primary bottleneck at 1680x1050 and 1920x1080.

This is because the resolution is too low for the gPUs. The GPUs are basically so powerful that that resolution relies on the CPU more than the GPU does. Not that the 3970X is weak, just that its doing most of the work at those res.

From:
http://www.tomshardware.com/reviews/radeon-hd-7950-overclock-crossfire-benchmark,3123-4.html

We've transitioned our test platform for graphics to a Sandy Bridge-E-based Core i7-3960X overclocked to 4.2 GHz. You'll notice that, in some cases, that's still not enough processing power to let some of our more demanding two- and four-GPU configurations really stretch their legs.

The biggest problem with three or four GPUs is that they don't scale very well. Two is pretty good these days. Near 100%. But 4 normally isn't, and for the most part you need to play at uber high res to even begin to utilize that much power.

Just to say it plainly, the i7 3K series will be more than powerful enough for probably the next 3 gens of GPUs.

 

[dbhelman]

Thank you for some insight. Excuse my ignorance, but it seems it could be an issue with how the CPU and GPU's communicate with each other...? Native PCI-E 3.0 potentially could allow better transfer rates in the future?

 

[jimmysmitty]

Thank you for some insight. Excuse my ignorance, but it seems it could be an issue with how the CPU and GPU's communicate with each other...? Native PCI-E 3.0 potentially could allow better transfer rates in the future?

Yes PCIe 3 will allow for 2x the transfer rates of PCIe 2. Just as PCie 2 is 2x that of PCIe 1. But it will probably be a few more gens of GPUs before they even begin to saturate PCIe 3 since even PCIe 2.0 x16 is not even saturated.