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Possible Bottlenecking Issues among other issues

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#1 Toyota_Supra


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Posted 10 April 2015 - 06:00 PM

Here is what I'm running:


Unigine Heaven Benchmark 4.0



Platform: Windows 7 (build 7601, Service Pack 1) 64bit

CPU model: Intel® Core™ i7-4790K CPU @ 4.00GHz (3997MHz) x4

GPU model: NVIDIA GeForce GTX 780 (3072MB) x1


FPS: 55.5

Score: 1397

Min FPS: 29.9

Max FPS: 116.9



Render: Direct3D11

Mode: 1920x1080 8xAA full screen

Preset: Custom

Quality: Ultra

Tessellation: Extreme


I have reason to believe that my CPU is bottlenecking my GPU.


The evidence that leads me to believe this is when running prime95 alongside Unigine Heaven 4.0, I see extremely low quality benchmarks. We are talking about 10 FPS low quality.

When I turn off prime95, I see more acceptable benchmarks of 50+ FPS with some spots reaching 100+ FPS.


From what I have read, this means that my CPU is bottlenecking my GPU.


Is there a way to fix this issue?


I have read that a fix would be to overclock the CPU.  I believe there is already an overclock on it. Not sure if it is a factory boost setting or if Ironside computers put it on there. It’s rated at 4.0 GHz but according to HWMonitor I’m running pretty close to 4.4 GHz.


Also, to compound this issue; while running Prime95 alone, my CPU temps reach 100C on multiple cores. It doesn’t stay there, It reaches it in around 30 minutes then goes back down to the 70’s, then over the next 15 minutes or so it slowly climbs back up to 100C again then slowly goes back down to the 70’s again. This repetition continues during the entire time Prime95 is running.


It only does this while Prime95 is running; my temps don’t go over 60C while doing anything else. So I am hesitant to try overclocking it more than it already is for this reason.


The fix for this would be liquid cooling. I already have a stage 2 Iron Tundra liquid cooling system (I’m assuming this is something that is named by Ironside). It has a very large radiator at the top of the case along with very thick transparent tubing for the liquid. The reservoir is full as well. On top of that there are 4 different case fans. The case itself is a Cooler Master HAF X. It is in a well-ventilated area. Not sure what I could do to get it cooler.


Another thing that may be worth mentioning (not sure if it is related or not) is that every time I turn my computer on and log onto WoW, both screens go dark for a few seconds and I get an error saying that my NVIDIA display driver has temporarily stopped working but has recovered. It only does this one time during my whole session. It does not do this again until I shut the computer down and start it back up again. I have read about a few possible fixes for it, I have tried rerolling back to a previous video card update, running MemTest to see if it’s my ram, and set the NVidia settings to prefer performance instead of energy saving. None of this has fixed this issue.


Does anyone have any advice that would help me out with these issues? I consider myself to be a novice when it comes with anything to do with computers. Everything that I have written is essentially the boundary of my computer knowledge.


Thank you!

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#2 Kilroy


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Posted 10 April 2015 - 09:41 PM

Your main problem is not understanding what Prime95 is designed to do.  Prime95 is designed to stress your CPU.  It won't matter if you put the fasted CPU on the planet in your machine Prime95 will stress it and you will get low frame rates (no matter your video card) if you are testing both at the same time.  If you're not having real world issues, don't worry about it.


The screen blanking may be fixed by updating to the latest driver from nVidia.  Before installing the new driver uninstall your old driver.

Edited by Kilroy, 10 April 2015 - 09:42 PM.

#3 killerx525


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Posted 10 April 2015 - 10:03 PM

Hello and welcome to the forum! Adding from what Kilroy mentioned, by running Prime95, it is taxing 100% of the CPU resource , hence when firing up Heaven the results are lower since that benchmark requires some CPU resource to achieve the highest score. The i7-4790K is no slacker, when it comes to performance and it certainly is not bottlenecking your 780, as in my personal system, i'm running a ageing Phenom II X6 1090T with 980 and runs beautifully in games at 4K. 


In regards to the CPU running at 100C during Prime95 is very concerning. What you can try is to reapply the thermal paste and re-fit the cooler in hope it will fix the temperature issue. Also the CPU running towards 4.4GHz is only the automatic turbo boost kicking in during heavy loads.

System1: CPU- Intel Core i7-5820K @ 4.4GHz, CPU Cooler- Noctua NH-D14, RAM- G.Skill Ripjaws 16GB Kit(4Gx4) DDR3 2133MHz, SSD/HDD- Samsung 850 EVO 250GB/Western Digital Caviar Black 1TB/Seagate Barracuada 3TB, GPU- 2x EVGA GTX980 Superclocked @1360/MHz1900MHz, Motherboard- Asus X99 Deluxe, Case- Custom Mac G5, PSU- EVGA P2-1000W, Soundcard- Realtek High Definition Audio, OS- Windows 10 Pro 64-Bit
Games: APB: Reloaded, Hours played: 3100+  System2: Late 2011 Macbook Pro 15inch   OFw63FY.png

#4 Serpius


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Posted 11 April 2015 - 07:24 AM

Here is what I'm running:


I have reason to believe that my CPU is bottlenecking my GPU.


** Rest of post deleted for brevity **


Does anyone have any advice that would help me out with these issues? I consider myself to be a novice when it comes with anything to do with computers. Everything that I have written is essentially the boundary of my computer knowledge.


Thank you!




As a few others have stated Prime 95 is more for testing the CPU.


Find a testing program that is geared towards testing the graphics card.


I believe that the RAM modules may be suspect.


Slow speed RAM modules have been known to bottleneck the data flying between the CPU and the graphics card. Since you did not post your RAM modules specs, I cannot speculate further until we get the RAM info from you.


Your power supply unit. Most of the high end graphics card requires 600 watts or greater. On top if that, you have a liquid cooling system and that requires wattage as well. If your current PSU wattage is too low, that will cause some problems.


Since, you did not post your PSU brand and/or wattage, I cannot comment further on this.

#5 DJBPace07


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Posted 13 April 2015 - 07:03 AM

There are GPU benchmarking tools, such as Furmark, which could help if you're wanting to benchmark the GPU or stress it.  Prime95 is meant for stressing the CPU.



#6 synergy513


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Posted 14 April 2015 - 06:18 AM

there is also the unigine valley graphics benchmarking, it has settings like the heaven edition. the user can adjust the settings to find potential bottlenecks.


also, MSI afterburner is what i use to test cpu cooling, it has a cpu maximum load app like others i would believe.

Edited by synergy513, 14 April 2015 - 06:19 AM.

Moore's Law : 4d Graph in Progress

#7 Tuck53


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Posted 14 April 2015 - 12:59 PM

If your CPU is running at 100C on heavy load it will be thermally throttling. Your cooling solution is a problem, if using the standard Intel cooler then it is poorly thermally joined with the cpu. As B Aussie says , it needs cleaning and re-applying of good quality thermal paste.


I would suggest an aftermarket cooler is a better option, there are many good ones on the market from Zalman, Noctua, CoolerMaster, etc. You can get a decent one for £20-30 ($30-45) , well worth it.

I have an overclocked CPU running at 70C in a Lian Li briefcase with a Zalman low profile cooler so your setup should be at 45-55C max.

#8 defanged


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Posted 19 April 2015 - 11:45 PM

don't forget to clean off the old paste (CAREFULLY!!) before applying a new, fresh coat...

SETUP, as of 4/14 - Case: Corsair 900D full tower, PSU: corsair 1200 watts, MB: ASUS rampage IV extreme, GPU(s): 3 X Nvidia GeForce GTX 780 hydro copper classified in 3-way SLI , RAM: 64 GB corsair dominator platinum DDR3, CPU: i7 3970X extreme edition @ 3.5 GHz (hexacore), OD: ASUS blu-ray RW, Cooling: EK liquid system, incl. EK waterblock, EK fittings, EK pump, resevoir, coolant misc., generic tubing, Audio: Creative sound blaster Recon3D THX PCIE Fatal1ty Champion sound card, Storage: SSD/HD: 2 X 240 GB samsung SSD (OS - win 7 pro), 1 TB caviar black, 4 TB caviar blue.

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