Widescreen Gaming Forum

Sorry to sound like an arse, but I think most people realised the higher the resolution the less the CPU clock speed matters...

What would be interesting is seeing how FPS is related to the "FSB" speed of the Sandy/ Ivy Bridge, as that effects the speed of the PCI-e bus too.

I realise that the "FSB" is basically a clock generator for every other bus connected to the CPU, what I was meaning was if you ran it at say 105Mhz instead of 100Mhz, thus giving, theoretically 5% more bandwidth, whilst keeping the clock speed fairly similar (you could run 100x40 for 4000Mhz give or take and say 105x38 for 3990Mhz give or take), it would just be interesting to see if the increase in bus speed would help the FPS more than the large % increase in clock speed did/didn't.

His card is a PCI-e 3.0 card being driven from a 2500K on a Z68 board, which are both PCI-e 2.0

I was personally interested if you fed the 7950 more bandwidth from the PCI-e slot if you would get more bang for buck than just overclocking the CPU, but seems you don't wanna do that!

[quote]His card is a PCI-e 3.0 card being driven from a 2500K on a Z68 board, which are both PCI-e 2.0

I was personally interested if you fed the 7950 more bandwidth from the PCI-e slot if you would get more bang for buck than just overclocking the CPU, but seems you don't wanna do that!

it's 16%. so really not very small to nonexistent.

We have put forth a great effort to get to the bottom of the PCIe 2.0 versus PCIe 3.0 debate. We put a lot of time into testing performance and verifying that our data is accurate. Except for a couple of specific scenarios, most of the performance advantage had under PCIe 3.0 was well under 10%. This actually falls in-line with the kind of performance advantages one might expect using n Ivy Bridge CPU clock-for-clock compared to a Sandy Bridge CPU. The IPC can affect performance by as much as 4-7% in favor of Ivy Bridge easily. As you noticed, most of our data when we experienced an improvement on the Ivy Bridge system was in this range of improvements. There were a few specific cases of 11% in The Witcher 2 in one test, and 19% in Batman (for part of the game only) and 14% when we cranked up the settings to unplayable levels in Max Payne 3. For the most part, at the real-world highest playable settings we found playable, all performance advantages were under 10%.

With real-world gameplay performance advantages under 10% it doesn't change the actual gameplay experience. It in no way allows us to improve in-game quality settings nor does it give us any advantages over the PCIe 2.0 system. As we've stated previously in this evaluation, the technical performance advantages are "benchmarkable" but not relating to the gameplay experience.

It is also very clear from our testing that the NVIDIA GeForce GTX 680 receives an overall higher percentage of improvements with Ivy Bridge than the Radeon HD 7970 does. It is possible that similar to our past CPU frequency testing, NVIDIA GeForce GTX 680 GPUs are simply more sensitive to CPU clock speed and IPC, especially when you scale these upwards. We've done testing in the past that also shows NVIDIA GPUs are more sensitive to CPU clock speed than AMD GPUs are as you scale those up to dual and triple-GPUs. Therefore, we are not shocked to find that one brand might benefit with a technology more than another. It is an interesting result that we didn't expect when we started testing.

So do not fret if you are on a Sandy Bridge PCI Express 2.0 system, you aren't missing out on a bunch of performance compared to an Ivy Bridge PCI Express 3.0 system. Most of our readers will likely benefit from higher CPU overclocks on Sandy Bridge anyway if you are truly pushing the CPU clock and this alone will likely negate any "advantages" from PCIe 3.0 or Ivy Bridge IPC when it comes to real-world gaming scenarios. PCIe 3.0 is a great evolution, one day it may actually support a better gameplay experience compared to PCIe 2.0, but that day is not today.

So what you are saying is that since PCI-E 1.0 won't slow down a PCI-E 3.0 card, running it in a PCI-E 2.0 system won't slow it down either.

PCI-e 1.1 16x (2.5GT/ lane (250MB)) = ~4GB/ sec                                         Crysis FPS: 59.15

   

   PCI-e 3.0 1x (8GT/ lane (800MB)) = ~0.8GB/ sec                                                      55.98

   

   PCI-e 3.0 16x (8GT/ lane (800MB)) = ~12.8GB/ sec                                                    60.67

I for one am not going to post anymore here now, you made it perfectly clear you are not going to run these benchmarks that would show the lack/ the increase in performance, I personally do not have the hardware to run them, so I guess we will never know.

Code: Select all

PCI-e 1.1 16x (2.5GT/ lane (250MB)) = ~4GB/ sec                                         Crysis FPS: 59.15

   

   PCI-e 3.0 1x (8GT/ lane (<span style="color: #900;">1GB</span>)) = <span style="color: #900;">985 MB/s</span>                                                           55.98

   

   PCI-e 3.0 16x (8GT/ lane (<span style="color: #900;">1GB</span>)) = <span style="color: #900;">15754 MB/s </span>                                                       60.67

Ungine follows the same trend, but not to the same extent.

You can clearly see that by running the card in a PCI-e 3.0x1 slot, which is a scenario that may happen using CrossfireX, or SLI for example with multiple cards, that instead of the control 100% performance you would expect, you get 92.3% of the performance.

I for one am not going to post anymore here now, you made it perfectly clear you are not going to run these benchmarks that would show the lack/ the increase in performance, I personally do not have the hardware to run them, so I guess we will never know.

Attached files

[quote]I for one am not going to post anymore here now, you made it perfectly clear you are not going to run these benchmarks that would show the lack/ the increase in performance, I personally do not have the hardware to run them, so I guess we will never know.

I don't like it when people make other people out to be wrong WITHOUT EVIDENCE.

This is the reason I wanted to see how the PCI-e bandwidth effected things. Although it is with a different setup to yours, I wanted to see if with a single card if it made any difference worth talking about. That was a all. I was so insistent because of how I had seen a 4 GPU setup behave.

Sorry if I came across as being an arsehole, but to basically refuse to run setups based on your "gut feeling" or whatever it was and then say I have strong opinions is a tad rich :)