New build stuttering/lagging? I'm lost =(

[rbrutoniii]

Hi! I just bought and built myself a new computer with the help of this site. It seemed to run completely fine for 2 days or so, but now it is skipping/lagging pretty severely at times. The audio (if playing) will screech/Skip, the mouse cursor will lag, and the system will kind of hang for around .5-1 second, and repeat from every 2-3 seconds to just isolated instances.

I noticed it first while playing Civilization 5, and at first it seemed confined to that. However, now I'm seeing it happen all the time (it just did it for 5-10 minutes after starting the computer, got better, then started again), although it doesn't do it all the time. While looking for a cause, I noticed a few things while it was occurring. The CPU temperature is at least ~10 degrees hotter in the bios (and continued to slowly rise) monitor then the Motherboard supplied monitoring software or HWmonitor. The first core seems to spike, it's like that thing is trying to replicate a mountain range, while the other cores sit dormant. I don't know what other information is pertinent, but will readily supply it. Can anyone give me some ideas or a place to start? Thank you so much...

* CPU = i5 2500k quad core
* Motherboard = AsROCK h61M-GE LGA1155R
* Video Card = Powercolor AX6850 1gbD5-DH R
* Power supply = Compucase HP575D RT
* Ram = 2Gx2 KHX 1333C7D3k2
* DVD drive = Lite on IHAS124-04
* Hard Drive = Western Digital 320GB SATA 6gb/s
* Some cheap wireless pci card
* Windows 7 64bit

According to CPUID HWMonitor - the cores are all within 20-32C
And these are my voltages (do you need other ones and where do I get them?)

Hardware monitor Nuvoton NCT6776
Voltage 0 1.00 Volts [0x7D] (CPU VCORE)
Voltage 1 1.86 Volts [0xE8] (VIN1)
Voltage 2 3.38 Volts [0xD3] (AVCC)
Voltage 3 3.36 Volts [0xD2] (3VCC)
Voltage 4 0.12 Volts [0xF] (VIN4)
Voltage 5 1.74 Volts [0xD9] (VIN5)
Voltage 6 1.06 Volts [0x85] (VIN6)
Temperature 0 22°C (71°F) [0x16] (SYSTIN)
Temperature 1 24°C (75°F) [0x30] (CPUTIN)
Temperature 2 23°C (72°F) [0x2D] (AUXTIN)

I also ran memtest86 and it passed

 

[DXRick]

What does Task Manager show?

 

[rbrutoniii]

Cpu usage is usually quite low, however when the system is messing up - One core is spiking all over the place while the others flatline, and system interrupts is the highest in the average cpu usage in the Windows Resource Monitor, while when it is fine it's not. That's the only difference that I have noticed.

 

[Raiddinn]

Did we advise you to get the

Compucase HP575D RT

PSU?

I think you should start by replacing that with a good one instead.

Try an XFX 550w or XFX 650w instead.

PSU problems can mask themselves as problems with anything else and no part can be trusted in the PC if the PSU can't be trusted.

Before we can try to rule out what is and is not the problem we need to have a trustable PSU powering everything.