Help with serious FPS issues despite good PC.

Hey guys, I'm an amateur when it comes to PC hardware and specifications, so I was hoping some more knowledgable folks on here could help me out. I have spoken with several different people who have tried to figure it out but it's proven to be futile so far. The only two games I play for PC are Diablo 3 and Oblivion (With a few texture mods and all settings turned max and on 1920x1080) but I am pretty sure there is something wrong with either my processor or my GPU. Or something is bogging one of them down. I have a GTX 670, 16 gb RAM, AMD FX 6100 ( Yeah I know it's a shit processor but it still should be able to run Diablo 3 and Oblivion no problem, even maxed out) Diablo 3 used to run perfectly, then after a couple months I started noticing major FPS drops when there was a massive battle on the screen, and it had never happened before. Then I just kind of stopped PC gaming for a while and now I've recently started back up with Oblivion. I maxed all settings out and like I said threw some texture mods on there and it has no problem in non fps intensive areas. I'll get 100+ FPS in those areas. Then the second I swing my camera towards some really fps intensive areas, I'll go from like 120 fps down to 25. It's ridiculous. I have been monitoring usage on GPU and CPU cores with MSI afterburner and no one core goes above 85%, and if it does, it shares part of its load with another cpu and then goes back down and the other cpu that took part of its load then goes up in percentage. My GPU % usage during all of this is: 90-100% when looking at non fps intensive areas at 120 fps, then drops down to 25-40% when I swing around and look at fps intensive areas of 25-35 fps. All the while, like I said, no core is getting to 100 or even 90 % so that's what makes me think it's not just a simple cpu bottleneck (because I've read many sources that say the cpu usage needs to be at or near 100% and the gpu usage needs to be low for it to be a cpu bottleneck. If anyone can please help me I would appreciate it so much.

Does your harddrive thrash when the fps drops? How old is your OS install and when was the last time you have done malware/virus checks? Checked to see whats running in the background? Have you done a clean gpu driver install? One clear way to rule all software and driver issues would be to start fresh with windows.

@04dcarraher: what do you mean by my hard drive thrashing when fps drops? If you mean make any sort of noise no it does not. OS install is about 2 1/2 years old. Did several malware and antivirus removals. Background processes are not draining CPU because when idle its never above 1%. If by clean GPU driver install you mean update the drivers or roll back the drivers I've done both of those. Or do you mean uninstalling the driver and re installing? And I'm honestly not sure how to start a fresh Windows install because a buddy did everything for me so I haven't a clue how to do it.

I mean is your harddrive being constantly used while the issue shows?, Clean install of the latest drivers,

LOL dude, Diablo 3 is very badly optimized when it comes to huge battles, I play on lowest settings just to be able to run at 60fps all the time (i5, 280X)

Try lowering your settings or just get a better CPU/GPU to be able to run this game better, it's funny because all of this time and they still didn't optimized the game on all of it's parts of the maps.

Note I get major drop in fps when try crossing some bridge or wall on the 4th chapter

@jeffray2323: Check your CPU Temps under load and gpu, run prime95 and keep cpuz open, if the clock rate in gpuz drops at all under load your cpu is overheating and downclocking for a few seconds then going back up. Also try getting beta gpu drivers or rolling back. Might also be worth running a hard drive test if u can.

With diablo 3 it could be you have too many sound channels turned on, especially with a lower end processor. Try setting it to low (32 channels) if you haven't already.

@zaku101: OK so which programs do I need to have up? CPUz, gpuz, and prime95? All three? Also cpuz and gpuz don't sit in my game window like MSI afterburner does so I can't check temps under load because if I minimize the game to look at them it takes the stress off the PC so it won't show anything useful.

First just test the CPU, need CPU-Z open and prime95 select to run the first test. Then watch the CPU-Z "Core Speed" it should stay at full speed under load if it keeps dropping and going back up it's overheating. For the GPU just install the program furmark and run it at max settings, check the GPU temp and if the clock speed drops. If everything passes message me again and I'll provide you with software to test your hard drive.

@zaku101: OK. I'm assuming prime 95 select is a program that stresses a CPU so I can watch the core speed?

Run the game windowed and see if you can replicate the slowdowns.

Yup, start it up and select small FFTs, then watch it in CPU-Z.

http://www.mersenne.org/download/#download

@jun_aka_pekto: how do I run a game in windowed? Also, if the problems stop when it is windowed, what does that mean?

@zaku101: I did that, but nothing seemed to do anything. I'm not sure if I ran the test correctly but here is what my prime 95 window looks like after I start the test and stop it. Nothing seems to happen when I start the test though.

https://app.box.com/s/2j6oj00jwnxepoyt6mhsqds1hb7chc59

Don't worry, that's not a virus. It's a file sharing site called Box.com you can check it out for yourself if you want. Before clicking my link. But that is a link to download a screenshot of my prime95 so you can see if I did it right.

Also, I downloaded Furmark and the test was this big ass colorful image that just kind of shifted around for a while. Well while running Furmark my GPU usage stayed at 0% the whole time and all of my cores on my CPU were at 100% the whole time. Temp on GPU was just fine. 51 celcius

Also just for extra info I ran the CPU burner in Furmark and watched CPU z, my core speed never went lower than 2992 MHz and bounced around between 2992 and 3590 MHz during the test. Core voltage kept switching between 1.285 v and 1.368 v

When you're in a game, go to settings and it's somewhere next to resolution settings, choose to run the game in "windowed" instead of "full screen".

@jun_aka_pekto: yes the fps problem still persists.

@jeffray2323:

It should look like this while it's running, did you stop the test?

In the second screenshot the Core Speed should not be changing while the test is running. It should be staying at whatever your stock CPU clock is suppose to be Which should be about 3.3Ghz - 3.6ghz (Turbo Mode) if your running the test and it keeps changing from example (3.6/3ghz to 2.8ghz or less) it's overheating. I would download the program Speccy and look at the CPU temp through it.

https://www.piriform.com/speccy

Also for Furmark GPU should be at about 99% usage, you must have done something wrong... Use GPU-Z to make sure you're getting the right readings.

You can check your cpu temps using MSI afterburner ( the latest versions allow that ). Also enable gpu usage monitoring in MSI Afterburner to see if you are been bottlenecked by your cpu ( which i'm almost certain you are especially in large battles and considering Diablo 3 dont take advantage of more than 2 cores )

If I were you id just do a fresh os install first possibly on another hdd if you just want to check whether that's the problem. One other thing that is commonly overlooked when building or upgrading a PC is the power supply believe me I know because it took me three different builds before I realised all of my problems were due to this even though my psu was 1000w it was just unstable (early ocz psu).