Computer shutting down / PSU upgrade necessary? / AX or TX for a gamer?

[Niko.D]

Hello there!

 

I'm new to this forum although I am a happy Corsair customer for many years now. So please forgive me for making a wall-of-text posting as my first thread here. :):

 

About three months ago, I upgraded my CPU from dual core to quad core and doubled the amount of my Corsair RAM from 8GB to 16GB. Due to having a busy job I had no chance of playing my computer games for any longer session since then, until recently. My CX500 PSU is now two years old and I have never had any problems with it; however, since several weeks ago, my computer would suddenly shut down (as if someone pulled the plug), when the system stress (be it from the graphics card or CPU) would increase past a certain limit. It would do this for example when running around in my Star Citizen hangar, or in SWTOR when reaching a certain area on VOSS, where a lot is going on graphics-wise. I'll hear the graphics card fan speed up to compensate, and the computer will shut down. I also tested this with a memory testing tool that also puts all CPU cores under some stress; with the same result, the PC shuts down.

 

Is my PSU too old and did it lose some of its efficiency because of its age? Or is it simply too weak to support the bigger CPU and RAM? Is it broken or can I still use it on another PC with less power hungry hardware?

 

My gut feeling tells me, it's time for a PSU upgrade and -after some research- I already ordered an AX860 to give my PC all the power it needs. However, I may have been too hasty in my decision, since I now found out that the TX850M has a higher amperage (30A) for 3.3V and 5V than the AX860 (25A), although both provide the same amperage (~A70) on the 12V rail.

 

I chose the AX860 because of its better efficiency, but now I am not so sure any more about my decision: Would a TX850M be better suited for a PC that is mainly used for gaming, surfing in the internet, watching DVD's and sometimes doing some software development? Or was the AX860 the better choice after all?

 

Apart from the 12V amperage, is there any downside to the AX860, compared to the TX850M? I already know that my graphics card needs enough amperage on the 12V rail, but how important are the 3.3V and 5V amperage for my PC?

 

Edit:

I want to add that the computer only shuts down, when there is a lot of stress for either the CPU or GPU (and even then only sometimes). After the shutdown, the computer restarts without problems and the only entry in the Windows event log is about the sudden shutdown, but with no indication on what caused the shutdown. Also, on days where I only use the PC for other things than gaming (or stress tests), it does not shut down.

 

 

Best regards, Niko

[peanutz94]

All of those PSu are so close in specs it wont matter in your machine. So it's basically what you like over the others.

All of Corsairs PSU are more or less aimed at the enthusiast /gamer type.

 

 

As far as your shut downs are concerned, did you ADD memory to your current set when you upgraded?

 

What do your voltages read for your 12, 5v, and 3.3v rails.

[Niko.D]

Thank you for your fast answer! ;):

 

 

All of those PSu are so close in specs it wont matter in your machine. So it's basically what you like over the others.

All of Corsairs PSU are more or less aimed at the enthusiast /gamer type.

That's good to hear! :):

 

 

As far as your shut downs are concerned, did you ADD memory to your current set when you upgraded?

Yes, along with my CPU upgrade three months ago I also added another 8GB of RAM to my then existing 8GB of RAM. I now have 4 bars of the same Corsair RAM (Corsair XMS3 Dual Channel DDR3) where I before only had 2.

 

 

What do your voltages read for your 12, 5v, and 3.3v rails.

According to Asus PC Probe II my voltages currently are:

+3V -> 3.31V

+5V -> 5.06V

+12V -> 11.98V

 

The last time I made a stress test with OcBase's program OCCT, the computer shut down after ~1 minute into the test. I watched PC Probe II the whole time and saw no major change (larger than 0.05V in any direction) in any of the voltage values.

[peanutz94]

Quote:

Originally Posted by peanutz94 View Post

As far as your shut downs are concerned, did you ADD memory to your current set when you upgraded?

Yes, along with my CPU upgrade three months ago I also added another 8GB of RAM to my then existing 8GB of RAM. I now have 4 bars of the same Corsair RAM (Corsair XMS3 Dual Channel DDR3) where I before only had 2.

Unfortunately apart from the part numbers being the same , they are viewed and treated as two completely different sets. Small differences between the two sets can and often will cause crashes and instability.

 

I would isolate your two kits and try each on it's own and see if your system returns to stable.

 

But i don't see anything in your OP or added details that says your PSU is failing.

[Niko.D]

Unfortunately apart from the part numbers being the same , they are viewed and treated as two completely different sets. Small differences between the two sets can and often will cause crashes and instability.

 

I would isolate your two kits and try each on it's own and see if your system returns to stable.

 

But i don't see anything in your OP or added details that says your PSU is failing.

Well, all the people I asked so far about a possible source for the sudden shutdowns when the system stress increases, told me it would most probably be the PSU and that I should get an upgrade for it; so that's what I did.

 

So what you're saying is that the same RAM isn't really "the same" any more (even with same size, MHz, model, manufacturer, etc.), and that these differences could cause the computer to shut down under certain situations? I didn't have any other problems so far, no bluescreens, no freezes, so I didn't suspect the RAM to be incompatible; and Windows didn't complain otherwise, either... :(:

 

But thank you for your advice, nevertheless. ;):

 

As soon as I get home after work, I'll remove each kit and try to reproduce the issue with OCCT (it should shut down after ~1 minute) with only one kit installed at a time.

 

Edit:

However, I think I'll keep the new PSU in any case; I plan on upgrading my graphics card later next year, so I might need more power anyways. :):

[peanutz94]

So what you're saying is that the same RAM isn't really "the same" any more (even with same size, MHz, model, manufacturer, etc.),

Yes and no. Even if it IS the exact same it is treated as an entirely different memory altogether. Corsair can not guarantee that any two kits are going to play nice with each other or not.

 

.Memory should be bought in one single matched kit. In your case it should have been a single 4x4gig kit. Always replace memory , never add.

 

 

But , yes, it can cause a hard shutdown in some cases. I suggested to check the memory because of your initial post. Is it most likely PSU? Probably. But it could also be memory and just another thing to check and rule out.

[Niko.D]

Swapping the RAM kits did not solve the issue; even with RAM from only one kit, the PC would still shut down after some time of running prime95. What did solve the issue was to deactivate 2 of the 4 cores of my CPU. The new PSU arrived in the meantime and I already sucessfully installed it, but the shutdown issue remains if all 4 cores are used, although the PC does not shut down as fast as with the old PSU.

 

It seems to me as if my three months old quad core processor is broken... :(:

[Niko.D]

Question:

Is 25A on 3.3V enough for a AMD Phenom II X4 945? Or did I buy the wrong PSU and should have bought one with 30A on 3.3V?

[peanutz94]

It's way more than enough. Your PSU, be it single or multi-rail is not your issue.

What did solve the issue was to deactivate 2 of the 4 cores of my CPU. The new PSU arrived in the meantime and I already sucessfully installed it, but the shutdown issue remains if all 4 cores are used, although the PC does not shut down as fast as with the old PSU.

This would suggest it's either your board or CPU . It's not the PSU if the old one produces the same results.

[Niko.D]

It's way more than enough. Your PSU, be it single or multi-rail is not your issue.

 

This would suggest it's either your board or CPU . It's not the PSU if the old one produces the same results.

After some more testing I can say that it's not the mainboard. My father has the same CPU in one of his computers and borrowed it to me for testing: The issue does not occur with his CPU on my mainboard while using all 4 cores, but it occurs reproducably with my CPU.

 

I wondered about the necessary amperage to operate the Phenom II X4 945 to its maximum of 125W, that's why I asked about the 3.3V rail. But apparently there are a lot of people out there using that very CPU with PSU's with 25A for 3.3V, so that should not be an issue after all. Also, like I wrote above, the identical CPU from my father worked flawless.

 

Good thing it's only a few months old (and well within the period of warranty); so I'll send my faulty CPU in for replacement, and hope I'll get a better one this time. For the time being I'll use only 2 of its cores, since in that mode it runs stable.

 

The new AX860 PSU however, I'll keep. I like its modularity and that it allows for future upgrades of my mainboard, CPU and graphics card. And since my old PSU is still flawless despite my suspicions, it will find a new home in one of my fathers' computers. :):

[peanutz94]

Sorry to hear about the CPU , but I'm glad you finally found the problem. Thats half the battle sometimes.

 

Just let us know if you have any more issues or questions.

[Niko.D]

Thanks, I'll do that! ;):