Last week I bought a new PC and I've been busy overclocking the CPU (also posted elsewhere about this). The CPU is an i7 4790K. I have it running at 4.5 GHz on 1.2 V now with HT off (because HT makes things a lot hotter). Just now I wondered if this OC is of any real use for me because by default the CPU boost clock is 4.4! That's only 0.1 less than my OC! And with my OC that CPU runs at 4.5 all the time while without an OC it only runs faster when needed which maybe is better for the CPU. 

 

My old CPU had a default speed of 3.3 so OC'ing that one to 4.5 was a no brainer. But I wonder if OC'ing this CPU is of any use (unless I can get it to 5 GHz, which I can't). Maybe Intel boost doesn't work too well and it never makes my CPU reach the 4.4 mark due to various reasons? The advantage of OC'ing is that I am certain the CPU will run as fast as it can. 

 

I also wonder if not OC'ing and keeping HT on will have any benefit in Prepar3D but maybe I should ask that in the P3D forum.

I definitely would not overclock! That's quite an increase over the 3.9 turbo boost in my 4770K and I would suspect NickN would say you are crazy for overclocking too as he indicated in one of his topics that a 4.4GHz overclock on an i7 4770K is equal to a 4.8 GHz o/c on an i7 2600K (I think it was one of the original Sandy Bridge CPU's). I see you are moving up from an i5 2500K so this should be some boost for you in both FSX and P3DV2. I currently have my i7 4770K o/c'd to 4.2GHz and get great performance. NickN said a 4.2GHz was equal to a 4.6GHz overclock on an i7 2700K. Overclocking causes many other issues sometimes like overheating and wrong voltages, etc., so I'm all for not overclocking if at all possible.

 

Remember to update your PC profile with your new system!

 

Best regards,

I would beg to differ... if the temperatures are OK, 4.5 GHz is not at all excessive..

 

Check in CPU-Z what clock your CPU is running at when idle.. if you have the power settings set in Windows, the CPU should throttle down when not loaded.

 

Also, if the 4790 is at all like my 4770, the Intel boost holds only if you have one core loaded,

so you may not get 4.4 when running FSX, but some lower number.. in which case you are better off setting it yourself.

 

Intel fine-print:

 

"Max Turbo Frequency refers to the maximum single-core processor frequency that can be achieved with Intel® Turbo Boost Technology. See www.intel.com/technology/turboboost/ for more information."

 

On my 4770k,  the advertised 3.9 GHz reduces to 3.7 GHz if multiple cores are active..

Last week I bought a new PC and I've been busy overclocking the CPU (also posted elsewhere about this). The CPU is an i7 4790K. I have it running at 4.5 GHz on 1.2 V now with HT off (because HT makes things a lot hotter). Just now I wondered if this OC is of any real use for me because by default the CPU boost clock is 4.4! That's only 0.1 less than my OC! And with my OC that CPU runs at 4.5 all the time while without an OC it only runs faster when needed which maybe is better for the CPU. 

 

My old CPU had a default speed of 3.3 so OC'ing that one to 4.5 was a no brainer. But I wonder if OC'ing this CPU is of any use (unless I can get it to 5 GHz, which I can't). Maybe Intel boost doesn't work too well and it never makes my CPU reach the 4.4 mark due to various reasons? The advantage of OC'ing is that I am certain the CPU will run as fast as it can. 

 

I also wonder if not OC'ing and keeping HT on will have any benefit in Prepar3D but maybe I should ask that in the P3D forum.

Try to get you voltage down my 4790k will do 4.5ghz  with 1.14V that dropped my temps by 10C from when I had it a 1.2V. I have hyperthreading on and I never get about 50c in FSX or P3Dv2 what cooler are you using?

FYI. I'm running 4790K at 4.8ghz. VCC @ 1.3v. H80i cooler at 55c Max during FSX usage. Ive never had FSX running so smooth that coming from a 2600K.

 

 

Remember to update your PC profile with your new system!

 

Good one! Profile is updated now.

 

 

 

Also, if the 4790 is at all like my 4770, the Intel boost holds only if you have one core loaded,
so you may not get 4.4 when running FSX, but some lower number.. in which case you are better off setting it yourself.

 

Yes, I've also read a few things about that! Seems that for every core that's used the boost drops 0.1 GHz. So while a normal boost for my CPU would be 4.4, it will be lowered to 4.1 with all four cores used. I rather keep on using my current 4.5 then.  ^_^ Also because the boost may use higher voltages, making things hotter than they are with my OC right now.

 

 

Try to get you voltage down my 4790k will do 4.5ghz  with 1.14V that dropped my temps by 10C from when I had it a 1.2V. I have hyperthreading on and I never get about 50c in FSX or P3Dv2 what cooler are you using?

 

1.14 is pretty low! I will see what happens if I use  a lower voltage. My cooler is the Noctua NH-D15.

Good one! Profile is updated now.

 

 

 

 

Yes, I've also read a few things about that! Seems that for every core that's used the boost drops 0.1 GHz. So while a normal boost for my CPU would be 4.4, it will be lowered to 4.1 with all four cores used. I rather keep on using my current 4.5 then.  ^_^ Also because the boost may use higher voltages, making things hotter than they are with my OC right now.

 

 

 

1.14 is pretty low! I will see what happens if I use  a lower voltage. My cooler is the Noctua NH-D15.

It would boot at 4.5 with 1.0v but wouldnt pass occt for more than a couple of min. I think I did well on the silicon lottery

I have extensively researched over clocking and have successfully done so for over 10 years.  Both CPU and GPU

 

Key is to keep CPU/GPU voltage and heat in check.

 

So long as you dont mind having to replace your CPU in say 5-8 years due to shortened life span, you're golden.

 

FSX is CPU bound so every percent performance increase will pay dividends.

 

Haven't read what Nick says about that, but he's just plain wrong (IMHO) if its contrary to what I just said.