I have some problems with my PSU. Sometimes when I start on the computer I can hear weird motor-like sounds coming from the PSU but it is probably the fan hitting a component or something, but it is not that big of a deal because I'm going to get a Corsair 850 W Gold-Certified Modular PSU (It should be more than enough for my Graphics Card).

The main problem that I have here is that whenever I start my PC and everything loads up when I try to play a game or sometimes watch a video the application which I'm using freezes but the desktop seems to be intact if I not click on it, because the desktop freezes too, and the same goes for every process/application. In turn every application freezes, even windows explorer. I then have to wait about 10-15 minutes for it to recover, but I usually end up restarting the whole system using the power button.

To avoid this problem, when the computer starts up and I log on, I have to go into a game or application which uses my Graphics Card, otherwise I will end up in a freeze-chain again. Also when I click minimize, maximize, or close on an application,(upper-right corner) or when I click on an application to show up on the taskbar, the mouse suddenly freezes for about 0.3-0.4 seconds, but then it works fine. This works every time I click.

My specs:

  • Dell Optiplex 990 Minitower PC with
  • Intel Core i5 2500K 3.3 Ghz Quad Core (2nd Generation) with about 100W Power Drain, Gigabyte Windforce AMD Radeon R9 270X 256-bit 2048MB Overclocked Graphics Card (Minimum 500W PSU),
  • 8GB 1400 Mhz DDR3 RAM (2*2GB, 1*4GB),
  • Seagate 7200RPM 500GB Internal Hard Drive
  • Edit: I forgot to add that I changed the PSU a while ago(5 months ago) from the factory 250-265W(I'm not so sure, it was a long time ago), to an ATX 500W PSU but it seems that it is not enough for this Graphics Card.
  • Your description is very detailed, but what is your question? How to fix it? Why it happens? Please explain Jan 26, 2015 at 10:37
  • What you're describing is usually caused by one of three problems. 1) You have too much loaded into RAM (too many programs open, too many background processes, etc.). The computer spends all of its time swapping stuff on and off the hard disk. 2) One or more programs are looking for things they can't find or trying to execute something that isn't working and waiting for it to finish. 3) You have more than one virus checker running in the background. Start with 1 & 3 and see if the problem goes away. If not, update your question. Dealing with 2 won't fit in a comment.
    – fixer1234
    Jan 26, 2015 at 21:20
  • I don't think any of these are the problem. Jan 27, 2015 at 18:03
  • 1) The RAM works perfectly fine as it is 15-20% loaded when idle so I don't think why that should be the problem. 2) I see that you mentioned Hard Drive, but I swapped to this Hard Drive about 3 weeks ago, so it's quite new. 3) I only have 1 anti-virus installed which is Vipre Internet Security 2014 so this choice is crossed out. Jan 27, 2015 at 19:17
  • My #2 is usually caused by a missing file or dependency, or a corrupted program. It causes the system to hang while it searches for what it needs or waits for a process to finish that eventually times out. They can be a bear to diagnose. You could try running sfc /scannow to rule out a system problem. Then it's a question of figuring out which program has the problem.
    – fixer1234
    Jan 27, 2015 at 19:51

1 Answer 1


The optiplex 990 isn't a good machine for gaming as it only has a 200-300w power supply. If you have an SFF 990 (small form factor) then you can't upgrade easily or cheaply. If you have the normal sized 990 then any 700w PSU will fit. 700w is the minimum wattage you should aim for.

  • I actually have an Optiplex 990 Minitower and I aggree. I edited a few hours ago that I have a 500W somewhat faulty PSU with noises some-like-what. But it's still not enough to handle Gigabyte AMD Radeon R9 270X Overclocked Graphics Card. I also noticed a huge performance drop on games which I play for example Assassin's Creed 3. Before I could run it on Very High no problem with 60+ FPS. But now it shows some graphics problems when I play it and a huge drop in fps to, to about 30-35 fps. Jan 27, 2015 at 22:40

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