Self build locks up/Runs seriously slow at random

Ichiroku

Honorable
Jul 14, 2013
2
0
10,510
Hey everyone,

I build a new computer about 7 months ago and ever since I had the problem that my computer would lock up at random times.
Specs:
CPU: AMD FX-8150 8-core black edition
GPU: Sapphire Radeon HD 7870 2GB OC Edition 1GHz Version (2x in crossfire)
Motherboard: Gigabyte GA-990FXA-UD3 Rev 1.2 (Bios Updated to newest)
PSU: Corsair CX750
RAM: Kingston HyperX Genesis DDR3 1600MHz

It could be watching a video and browsing the internet, playing a game (heavy or not), watching a video and playing a game... etc...

I've tried many and many things, I did Memtest86+ which gave no errors. I used Intel Burn Test to load my CPU, nothing happened. I used Furmark to burn my GPU, nothing happened.

My CPU goes to max. 65-70C when 100% loaded, my GPU goes max 67C when 100% loaded. So I don't think it's a temperature problem.

Sometimes my computer just completely locks, and sometimes my pc just goes VERY VERY slow, like 1 frame per 3 seconds slow. I can barely move my cursor around etc.

A funny thing that happened today is that I tried something I read on tomshardware. They said something about the VID from my CPU. I used CoreTemp to find the VID (1.400V) and used Open Hardware Monitor and CPU-Z to check the current VID. They said that if my VID drops below my 1.4V when under 100% load, there could be something wrong. So I looked into it and yes, my CPU runs around 1.2625V when under 100% load, sometimes jumping up to 1.4V, but then jumping back.

Now I was running Prime95, when I though "Hey, lets try GPU burning while I'm using prime95". I boot up FurMark and let it run. got around 70FPS with max temp of 67C. So I click it away and the moment I click it away it happened. My PC started moving seriously slow, could barely get to close everything down. It felt kinda weird because it felt like Prime95 was running fine while this was happening, jumping to the next test after the first 8 tests it did. Prime95 did not give any errors when I stopped it.

A funny thing about this is that the VID started to drop even lower, down to 0.8V while the CPU was still under heavy load!

When my PC is idle (like now while I'm typing) Open Hardware Monitor shows 1.4V to max 1.44V VID on my CPU.

I've already sent my Motherboard to the vendor using RMA, and they said they "repaired" it and send it back to me, so it is "probably" not a motherboard issue.

I've set the RAM Profile to Profile1 so it uses the correct latency, MHz and voltage (1.655V).

I've Updated all drivers, BIOS, Reinstalled Windows fresh twice etc.

I've tried using 1 videocard at a time (tested both).

TL;DR: While using Prime95 and FurMark together I was able to recreate the problem I got, PC locking up / slowing down immensly, but not giving any errors. VID dropped to 0.8V while this problem occurred.

Yours Faithfully,
Sem Wong.
 

Ichiroku

Honorable
Jul 14, 2013
2
0
10,510
Basically what happens is that my pc will suddenly start working REALLY slow. It feels like a lockup, as I hear no sound, I can't press any lighted buttons (capslock etc) untill it skips to the next frame. When it starts going to the next frame, I hear a tiny bit of the sound that was supposed to come with that frame, everything I did (move mouse, pressing buttons, etc) all do what I told it to do, and locks up again in that frame.

I let it go for about 10 / 20 mins, but it didn't recover at all, it stays in this situation till I hard reset it (Power off/on).

Additional information: I did send it to Paradigit (a local computerstore near my place) where they tested my system and it seems my system takes A LOT of power (around 600Watt). They told me it was either the Motherboard (which is why I send it to the vendor using RMA) or the PSU. The problem is though that I also get this problem when only using 1 videocard (I bought a new videocard later on, I had this problem from day 1). AMD says that I should only need about 500W for 1 videocard with all the stuff on it.

Edit: I'm an idiot lol, I dont have the CM one, I have a Corsair CX750 XD.

I'm in a serious pinch here, I'd appreciate any feedback right now.

I'll keep the PSU in the back of my mind, as the people from Paradigit also told me it might be a problem. However, if anyone knows what it could be other than PSU, then please tell me!