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BrettT

What is the effect of CPU Clock Speed

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I am curious.  In the absence of any other bottlenecks does an increase in CPU speed directly proportional to an increase in FPS

 

Assuming I have an i7-2600 that has a turbo clock of 3.8GHz and I get 30 fps.  If I upgraded this processor or overclocked to 4.4GHz (a 16% increase) could I expect a 16% increase or roughly 35 fps (is this the ideal advantage).  Or is it some other relationship, one that could be expect to yield even more fps or perhaps even less

 

Thanks for your input and thoughts

 

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Hi

 

just example on my system (as below), no increased on frame rate when i moved from 4.2Ghz to 4.4Ghz but dramatically increased (even at 4.3Ghz) after i applied the FSX tweak from Venetubo.com with external frame rate limiter.

 

- Intel core i7 980X @ 4.3Ghz

- Asus Rampage III Extreme Motherboard

- Corsair H60 Liquid cooling

- 6GB DDR3 Corsair Dominator

- Asus Radeon R9 280X 3GB GPU

- 120GB Scandisk SSD

- 750W Seasonic PSU

- 27" LED IPS HP monitor

- Windows 7 Home premium 64bit

 

- FSX SP2

- PMDG 737NGX SP1D

- EZDOK 1.17

- REX 4 Texture Direct

- My Traffic 2013

- Active Sky Net

- TrackIR

 

Hope it's help you.

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I am curious.  In the absence of any other bottlenecks does an increase in CPU speed directly proportional to an increase in FPS

 

Assuming I have an i7-2600 that has a turbo clock of 3.8GHz and I get 30 fps.  If I upgraded this processor or overclocked to 4.4GHz (a 16% increase) could I expect a 16% increase or roughly 35 fps (is this the ideal advantage).  Or is it some other relationship, one that could be expect to yield even more fps or perhaps even less

 

Thanks for your input and thoughts

 

There are many possible bottlenecks in a PC system, but if you have a fast motherboard, memory, and video card, then yes.

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Bert is correct.  If all the other hardware can handle the increased data output from a faster CPU, then you will see an improvement with FSX.  My experience has been that the percentage of overclocking the CPU does translate to an almost identical percentage improvement with FSX.

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Assuming I have an i7-2600 that has a turbo clock of 3.8GHz and I get 30 fps.  If I upgraded this processor or overclocked to 4.4GHz (a 16% increase) could I expect a 16% increase or roughly 35 fps (is this the ideal advantage).

 

You mention upgrading the processor as an option. If you are moving from a Sandy Bridge processor (i7-2600) to a newer generation i7 Intel CPU then even at like for like speeds you may well find a slight increase due to the improved architecture of the CPU, meaning if you upgraded to a i7-4790 with a turbo clock of 4GHz you may get slightly over 10% increase in frame rates. Obviously overclocking would yield greater results as long as you got the K series CPU and a decent aftermarket cooler so if you went to 4.4GHz (or more) the net effect could be higher.

 

Without knowing exactly what an "upgrade" would consist of it's hard to advise.

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Thanks Guys!

 

PieEater,

 

I presently have:

Asus-H67 Motherboard

i7-2600 @3.4

8GB Ram - 1333 MHz

560Ti GTX Vid Card

 

I am toying with the idea of doing a new build consisting of

 

Asus-Z97 Motherboard

i7-4790K @4.0

16 GB Ram - 1600 MHz

970 GTX Vid Card

 

The other thought I am having is just upgrading the Vid card to the 970 GTX

 

Clearly the new build is a much better system, but if the expected difference between doing the whole system or just the Vid Card is just the 17% improvement in FPS due primarily to the faster processor then I will likely just go with the vid card.

 

Thanks for your thoughts

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Thanks Guys!

 

PieEater,

 

I presently have:

Asus-H67 Motherboard

i7-2600 @3.4

8GB Ram - 1333 MHz

560Ti GTX Vid Card

 

I am toying with the idea of doing a new build consisting of

 

Asus-Z97 Motherboard

i7-4790K @4.0

16 GB Ram - 1600 MHz

970 GTX Vid Card

 

The other thought I am having is just upgrading the Vid card to the 970 GTX

 

Clearly the new build is a much better system, but if the expected difference between doing the whole system or just the Vid Card is just the 17% improvement in FPS due primarily to the faster processor then I will likely just go with the vid card.

 

Thanks for your thoughts

 

Hi,

 

if you want to save money, i would not buy 16GB RAM because 8gb is more than enough for a 32X application.

 

I have made a similar upgrade but starting from AMD X4 955 which is much worse than you CPU.

 

I think you can get 20-30% more just from the CPU at stock speed. Regarding oc i have the I7 4790K @4.7 with just 1.25 volt and very good temps so no brainer i keep oc. FPS seems around 5-10% better with OC.

 

Do you use FSX or P3D?

 

With FSX i think you are good with 560, for P3D GPU is more important (still less than CPU), GTX 970 is a good choice, imho one of the best value for $.

 

I have an ATI R9 270X OC @ 1.2GHZ, but going back perhaps buy a GTX 970 because with active sky next in some conditions the load goes up to 80% while the main core is not full maxed out, which makes me think that I would get better results with a better GPU... 

 

However, in my opinion do an upgrade of your rig with only the GPU makes little sense, if you don't get a better CPU you will use just a little of its potential...

 

CPU and GPU should always be proportional to each other not to waste resources, so go for I7 4790K and GTX 970 and you will not regret it....

 

edit ps: do not forget to overclock also the cache, it raised cache from 3,9 to 4.5 ghz with better results with core overclocked too (of course), i think cache is quite important for sims

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Alessandrov,

 

Thanks for the information.  I do have FSX but don't have any real investment in it with regards to add-ons.  I will likely play around with both X-plane X and P3D and then probably pick a favorite and invest in that.  In addition, I have also enjoyed the DCS products in the past as well.

 

In a somewhat related thought.  Both, the i7-4790k and the i7-2600 that I presently have, are equipped with turbo boost which is supposed to boost their clock rate under heavy load.  These become 4.4GHz and 3.8GHz respectively.  Since pretty much any flight sim is considered a heavy load all the time, does this basically become a defacto OC?  or if I chose to OC the processor to 4.5GHz does the turbo mode still kick in for an effective clock rate of 4.9GHz

 

Thanks for your thoughts

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Alessandrov,

 

Thanks for the information.  I do have FSX but don't have any real investment in it with regards to add-ons.  I will likely play around with both X-plane X and P3D and then probably pick a favorite and invest in that.  In addition, I have also enjoyed the DCS products in the past as well.

 

In a somewhat related thought.  Both, the i7-4790k and the i7-2600 that I presently have, are equipped with turbo boost which is supposed to boost their clock rate under heavy load.  These become 4.4GHz and 3.8GHz respectively.  Since pretty much any flight sim is considered a heavy load all the time, does this basically become a defacto OC?  or if I chose to OC the processor to 4.5GHz does the turbo mode still kick in for an effective clock rate of 4.9GHz

 

Thanks for your thoughts

 

Exactly, in FSX/P3D my cores are always running @4.7GHZ.

 

I had windows "power saving" off (top performance selected) otherwise sometimes a core clock may drop for a second and it causes instability.

 

Plus i suggest to apply registry optimizer (you can find it in NickN FSX "Bible" that switch off cores shut down (specially in case of HT=on, like i use that will make all cores work)

 

In my bios if i set core multiplier to 47 (4700mhz) that is the max turbo speed, infact default is 44 (4400mhz) so clock speed will not go faster than 4700.

 

I tried to overclock more the most bottlenecked core (the sims always tend to bottlenck main thread) but single core overclocking doesn't work well for me.

 

BTW I'm running P3D+ORBX+REX+ASN almost max settings with 30 fps locked and stable (not so in metropolies of course).

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With regards to your upgrade options I would bare in mind that there are 2 forthcoming releases that may be worth waiting out for, yes there will always be something better around the corner but nevertheless; 

 

The 980Ti may be released around August, the exact date is yet to be confirmed. Essentially this is the latest and greatest Titan X with half the memory (6GB vs 12GB), price will be a bit more than the current 980 but enthusiasts are already beginning to complain that the 980 with 4GB of VRAM is not enough to run games on their 4K monitors so the more powerful card with 6GB of memory would prove to be a better long term investment.

 

Intel should be releasing their Skylake processors around October, these are stated to have a significant performance increase over current CPUs, they will also be on platform that uses DDR4 memory as opposed to DDR3 used by the 4790K so the platform alone should also allow for a performance boost. I think going from a stock 2600 to an equivalent mildly overclocked Skylake should give you the kind of performance boost you are looking for.

 

In your shoes if I had an upgrade itch that wasn't going to go away I would get the best graphics card I could reasonably afford now and wait for Skylake. If the itch was controllable for now, I would hang fire to see what the 980Ti brings to the table in terms of price and performance and whether its release has any effect on the pricing of the current crop of cards.

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Thanks guys!

 

I might wait a little bit for either the broadwell or the Skylake to come out and either go with one of those or possibly let those drive down the cost of the i7-4790K system a bit.  Most likely I will probably stick with the 970 on the video card.  On most PC components I usually shoot for a sweet spot in the price/performance and never spend for the peak performance.

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