[SOLVED] PC shutting off randomly after installing new RAM

[FrankClinton_XPV]

My custom built PC started to randomly shut off after upgrading RAM.

System specs:
MOBO: GIGABYTE GA-H81M-S2PV Rev 3.0
CPU: Intel Core i5-4570 @ 3.20 GHz
CPU Cooler: Intel stock CPU cooler
GPU: Intel HD Graphics 4600 ( planning to upgrade to mid-range Gefore GTX )
PSU: Unbranded generic 500W ( planning to upgrade to branded 600W )
OS: Windows 7 Ultimate 64-bit Service Pack 1

RAM before upgrading - Kingston DDR3 1333MHz 4GB 9-9-9-24 Double-sided DIMM ( KVR1333D3N9/4G )
Before upgrading RAM, I had no problems so far.

As I wanted to upgrade RAM to 8GB, I added another 4GB stick of DDR3 1600 MHz.
Kingston DDR3 1600MHz 11-11-11-28 Single-sided DIMM ( KVR16N11S8/4 )

I added this 1600MHz stick because, I thought to manually OC 1333MHz RAM and run both in 1600MHz dual channel.
These two sticks POST with no problems even after OCing to 1600MHz.

But the problem is, when I try to play GTA IV or GTA V in very low settings, the game starts with no problems, and after some time ( after 30 seconds - 1 hour ), the computer shuts itself off, even without shutting down the OS, like someone pulled the power cord. Then, it starts back and POSTs.
Not just when playing games, this problem occurs very rarely on normal usage.

What I tried:
I monitored CPU temperatures with MSI Afterburner and they're fine. ( Idle at 40 - 45C, Load at 65 - 75C )
I tested both memory sticks individually with MemTest86 (4 passes) with no errors at all.
I tested both in dual channel ( 1600 downclocked to 1333 ) and still no errors at all.
But when I test both in dual channel ( 1333 OC to 1600 ), MemTest86 gives a warning at Hammer Test.

Note: Your RAM may be vulnerable to high frequency row hammer bit flips. However the conditions needed to induce these errors occur only very rarely in normal PC usage, and so this should not be of concern to most users.

What can be the problem? What's preventing these two sticks from nicely running together?

 

[MasterWigu]

That sounds like a PSU problem, can you try using another PSU? I think 500W should be enough for your system, but your Unbranded PSU can have some problem or cannot deliver the power it advertises.

 

[FrankClinton_XPV]

I have another 400W PSU, and I will try with it. But if it's a PSU problem, how does this system stay stable with just one 1333 or 1600 4GB stick?
Doesn't H81 Chipset support DDR3 1600 & 1333 RAM together?

 

[MasterWigu]

I have another 400W PSU, and I will try with it. But if it's a PSU problem, how does this system stay stable with just one 1333 or 1600 4GB stick?
Doesn't H81 Chipset support DDR3 1600 & 1333 RAM together?

I'm sorry, i didn't read your original question correctly. You should run both sticks at the lowest speed between both, in this case 1333MHz. Overclocking the 1333 stick to 1600 can cause this to happen, even if it sometimes works and posts. The ideal is to use always two equal or equivalent sticks (same speed and timings), but you can generally use two different sticks but at the lowest speed between them.

Anyways, there shouldn't be a big difference between running them at 1333MHz or 1600MHz.

 

[FrankClinton_XPV]

Yup there isn't a big difference between 1333MHz & 1600MHz.

I tried with 400W PSU, which only has one 4 pin CPU power connector. 400W PSU weighs more than this unbranded 500W PSU. Motherboard requires two 4 pin connectors, but I tried with this connector.
System did POST and windows loaded with no errors.

Your guess seems right, I didn't experience any shutdowns with this 400W PSU installed. I even tried overclocking slower one to 1600MHz, still no shut downs.
I always wanted to upgrade this PSU, because it's a low end one. But I just thought the problem was memory incompatibility, because the problem started to happen after adding another 4GB stick.

But I still wonder why this faulty PSU just handles one 4GB stick with no problems. When system running with one 4GB stick and faulty PSU, it never shuts down this way. Does adding two 4GB sticks draws more power ( 2 x 1.5V ) ?