CPU Spikes, stutter and freeze

[MNO]

Over the past week I've been experiencing slight audio stutters and screen freezes, at first they were a split second, now they're about 2-3 seconds long, happens surfing the web, watching a video or playing a game.

My CPU is randomly spiking in usage at the time of the freeze, and its "System" and "System Interrupts" that seem to take the highest usage. My 2500k i5 is at a constant 32-34c when the spikes happen so I know it's not the CPU overheating. Anyone have any ideas? Would help a lot. Meanwhile I'm off to do a memtest :/



Specs

ATI Radeon 7850 2GB
i5 2500k @ 4.0ghz
500w Corsair PSU
Z68a-d3-b3 motherboard
8gb Corsair Vengeance RAM



SMART Attributes (I have no idea what I'm looking at or what else is useful)

Spoiler

SMART ATTRIBUTES:
ID Description Status Value Worst Threshold Raw Value TEC
---------------------------------------------------------------------------------------------------------------------------------------------
1 Raw Read Error Rate OK 100 100 51 4 N.A.
2 Throughput Performance OK 252 252 0 0 N.A.
3 Spin Up Time OK 83 83 25 5234 N.A.
4 Start/Stop Count OK 100 100 0 995 N.A.
5 Reallocated Sector Count OK 252 252 10 0 N.A.
7 Seek Error Rate OK 252 252 51 0 N.A.
8 Seek Time Performance OK 252 252 15 0 N.A.
9 Power On Time OK 100 100 0 8878 N.A.
10 Spin Retry Count OK 252 252 51 0 N.A.
11 Calibration Retry Count OK 252 252 0 0 N.A.
12 Power Cycle Count OK 100 100 0 779 N.A.
191 G-sense Error Rate OK 100 100 0 277 N.A.
192 Power off Retract Count OK 252 252 0 0 N.A.
194 Temperature OK 64 58 0 29 C N.A.
195 Hardware ECC Recovered OK 100 100 0 0 N.A.
196 Reallocation Event Count OK 252 252 0 0 N.A.
197 Current Pending Sector Count OK 252 252 0 0 N.A.
198 Uncorrectable Sector Count OK 252 252 0 0 N.A.
199 UltraDMA CRC Error Count OK 200 200 0 0 N.A.
200 Write Error Count OK 100 100 0 11 N.A.
223 Load/Unload retry count OK 252 252 0 0 N.A.
225 Load Cycle Count OK 100 100 0 1022 N.A.

 

[MNO]

Added SMART attributes to the OP - not sure if it's useful or not but it means nothing to me, Disk Self-Tests come back with no errors. Doing a chkdsk now.

 

[MNO]

Any useful event logs during the freezes? That SMART data isn't exactly telling much, try CrystalDiskInfo.

No event logs during the freezes, I checked through Administration mostly and there's nothing.

Also downloaded CrystalDisk but doesn't seem to give any more information than Passmark DiskCheckup does, if it does I kinda need to know what I'm looking for

 

[MNO]

CrystalDiskInfo does report "Good". I didn't remove the CPU overclock when I ran memtest (but my RAM timings etc are all AUTO SPD)

Got a whole bunch of errors, I let it run for a short time and it was over 60+ - so fair to say it's the RAM? Or could my CPU overclock be forcing false positives somehow? No errors in the System eventlog.

 

[MNO]

I've been running memtest all afternoon and found it's only one stick of dual that is receiving a tonne of errors. So tomorrow I'll run the PC with the good stick and see if the freezes still happen, if not then I'll put it all down to the bad stick of RAM and get it RMA'd.

Does RAM sound like a fairly obvious cause of the cpu usage spikes/freezes?

 

[MNO]

Oh, and I should also add (forgot this bit) twice during the freezes over the past week, it's said "Display driver has become unresponsive and recovered" - but I assumed that was just because the whole PC was freezing up.

 

[MNO]

Okay so it's not the RAM. CPU Spikes and freezes still happening when I'm only using the "good" stick of RAM.


Edit: Update

So I didn't even know I could do this before, but anyway, with Process Explorer, I sat watching a video waiting for a freeze, then slammed printscreen (happens too fast to look) so I could see which System threads were responsible for the freeze.

This is what I got, I'm guessing 6.2 is a lot seeing as the highest I've seen any others go is 0.39. nltdi.sys is apparently something to do with NetLimiter (which I had installed) so I got rid of that. The ndis.sys is a bit vague and can't find anything specific but seems it's something to do with a Network driver also, haven't touched it with that, just going to see how things are with NetLimiter (and hopefully it's network driver/whateverthe****) uninstalled.