Huge FPS Drops While Gaming? (Now Desperate For Answer)

[rcss18]

Hello Toms Hardware! (Long time reader, first time poster/account)

Well, I recently purchased a new PC for gaming specific reasons. (Upgraded from a Q6600/HD6670 Combo)

While this new PC should be all lovely and run games quite well... it doesn't!
After about 3 minutes of game play my fps will drop down to near unplayable levels and after about 15 seconds it will shoot right back up; and then the whole process repeats.

For example: Saints Row 3 runs at 55-70 fps on max, and then suddenly drops to around 15.

This has happened ever since I first turned on the PC, and I have no idea whether its the PSU,CPU or Motherboard!
being a student, this has been very costly for me, and I am really frustrated as to why it is doing this.

Specs:

AMD FX-8150 CPU
HIS ICEQ HD 7850 2Gb TURBO
8Gb DDR3 RAM (Dual Channel)
MSI 760GM-P21 FX Motherboard
750w Powercool PSU

Any help would be greatly appreciated!
Thanks.

 

[simon12]

It sounds like overheating either CPU or GPU. Download HWMonitor or similar and check. Also I don't trust that power supply but there are no expert reviews about for it.

 

[rcss18]

Hi, I already ran HWMonitor (forgot to post results..)

My CPU gets to 57 degrees
And my GPU gets to around 57 - 60 degrees.

 

[cranachan]

I would get a better power supply, chances are it can't supply the amps (not necessarily the watts) and so the card is throttling itself back.

Get a power supply (500w ish) from a decent manufacturer such as corsair, seasonic etc. You don't need more than that for this build and besides even if it isn't the power supply that thing will explode in a couple of months/weeks and take most of your system with it. That will be much more expensive

 

[rcss18]

Yeah, thats what others have said.

But Im still not 100% sure it is the PSU... The motherboard is rated 95w and the 8150 is 125w.
Couldn't this be the cause?

 

[simon12]

Run some stress tests and see if it crashes, OCCT has a CPU & a GPU test.

 

[rcss18]

I ran FurMark with HWMonitor open.

My GPU temps reached 55 degrees maximum, and my results were between 28-32fps.. Thats pretty normal?

However, I ran Prime95 and my monitor went black after about half an hour (I needed to shut off my pc to get the display back.
My CPU reached around 58 degrees during the Prime95 test.


When I tested Saints Row 3 only 2 cores were really used, and the 2 cores never went above 90% (reached 90% and fell back down to 75%)

 

[simon12]

Its not overheating then, but something is not stable to cause the prime 95 crash. I suspect its the power supply but it could be the RAM or CPU. Try running prime 95 and the OCCT GPU test at the same time if it is the PSU then this should cause a crash very quickly.

 

[noob2222]

Yeah, thats what others have said.

But Im still not 100% sure it is the PSU... The motherboard is rated 95w and the 8150 is 125w.
Couldn't this be the cause?

absolutely. the VRM on the motherboard isn't strong enough to push the draw that the cpu is trying to get. The board is throttling the cpu to protect the VRM.

 

[rcss18]

Did some more research on my current motherboard, and apparently it is barely 95w capable (FX 4100 was also being throttled).
So it looks like this board is most likely to blame then.

Found a board within my budget (£42... almost like I'm rich)

"Gigabyte GA-78LMT-S2P" - It has 125w capability and has pretty positive reviews, I believe this is the upgrade I should perform.

 

[simon12]

8150 is not on the supported CPU list

 

[noob2222]

Did some more research on my current motherboard, and apparently it is barely 95w capable (FX 4100 was also being throttled).
So it looks like this board is most likely to blame then.

Found a board within my budget (£42... almost like I'm rich)

"Gigabyte GA-78LMT-S2P" - It has 125w capability and has pretty positive reviews, I believe this is the upgrade I should perform.

http://www.gigabyte.com/support-downloads/cpu-support-popup.aspx?pid=4125

no cpu on that list is 125W. Rev 3.1 supported the 4 and 6 core 125W cpus, but since have been removed from the list. I wouldn't trust it.

thats one of the problems with most of the 7xx boards.

MSI 760GM p34 (not the p33) supports 125W http://www.msi.com/product/mb/760GM-P34--FX-.html#/?div=CPUSupport
Asus m5a78L-M LX (LX only and not the LE) http://www.asus.com/Motherboards/M5A78LM_LX_V2/#specifications
Biostar A960A3+ http://www.biostar-usa.com/app/en-us/mb/introduction.php?S_ID=575#cpu

thats the cheapest boards that fully support 125W fx chips.