So, I'm playing Skyrim on the system I just built today, enjoying 60 fps with a higher-end ENB, when suddenly, the system goes dead.  It tries to reboot, but after the normal "Beep chirp", it let out five beeps, I'd have to call them short.  Tried reset button, no good.  Had to cold power down, and back up (I was never so glad to see the Windows logo in my life.), and it got me back into Windows.
 
I was too busy noticing the new frigidity of my blood to see what code the mobo was showing, but it was accessing the HD like it was trying to boot, but no video and the keyboard and mouse lights kept flashing on for a few seconds, then off.
 
What happened?  Here's my system; just built today:
 
EVGA X99 FTW, BIOS updated to 1.17
EVGA 750 Supernova G2
EVGA GTX970 SC 4 GB running 353.38, running 1 Samsung 1920x1080 monitor
16 gb Corsair Vengeance 2666, 4x4GB in 1, 3, 5, 7, running XMS Profile #1 for 2667
Intel 5820k, stock clocked
Windows 8.1

System rebooting/shutting off suddenly while gaming = psu. Contact tech support and ask them what 5 beeps mean. 

Your board uses a ami (american megatrends inc.) bios. 5 beeps = cpu error.
 

That doesn't make sense...the computer tried to start up; there just wasn't any video - I could see the HD being accessed.  I did look at the on-board display and it was showing the CPU temp - 56-58.  I did get into the BIOS and set the RAM to Auto, meaning it booted at 2133. (Which is the default for a stock clocked 5820, if I recall)
 
Just now, I timed Skyrim.  It crashed after three minutes.  After a restart, I ran the Valley benchmark at full setting (no 3d, though), and it ran fine for over four mins with vsync off; no crash.  The GPU temp never went over 75 C.

you also may want to set MB bios back to default, restart and then do this.

heres a good how to if needed, thanks to Sajin  
 
http://forums.evga.com/FindPost/2354878

Sajin
Download 3dmark, select the welcome menu, select "run all tests", let all tests run. Where you able to pass all the tests without the computer going dead?

Yes, all the tests.
 
I just set the memory back to the 2667 mhz profile; which the memory timing in the BIOS matched the ones on the RAM, and ran through all the primary tests again.  No problem.
 
I also set the PCIE config from Auto to Gen3 like I saw on the Geforce forums. The GTX 970 is the only card in the system.
 
EDIT: Just tried Skyrim again... this time, it made it eight minutes before crashing.  :/  I'd thought I was home free.

vitanksi
Are you running any mods in skyrim?

Lots, but nothing that wasn't running fine on my previous GTX570/Core i7 920 system - pretty much the only change I made was to install the "high quality" version of the ENB I was using; instead of the default. Besides, I play with VSYNC on, and have a 60 hz monitor.
 
My free copy of Arkham Knight finished downloading last night; haven't tried that yet.

vitanksi
try disabling mods and reenable one by one.  they can be problematic.
 

 
+1  Agree.
 
Also check and see the Vram usage as Skyrim with mods eat it up.

Well, I just ran the Intel Processor Diagnostic Tool, and the CPU passed.  About to try EVGA Precision and downclock my 970 SC to "stock" speeds. Meaning, the speeds of a non-factory-overclocked GTX 970.

Hmm... what happened to my reply?  Anyway, short version; downclocking the GPU to non-SC speeds with Precision let me play Skyrim for more than 33 minutes with no crash; and I don't think the GPU temp went much above 65 C.
 
It handled the benchmark and CPU burner tests in OC Scanner, though I didn't run them for long.

Yes, but I don't think it's unique to my card; it seems to affect the GTX 970 SC ACX 2.0 specifically. I found this while searching:
http://www.overclock.net/t/1556296/evga-gtx-970-sc-acx-2-0-keeps-crashing-to-black-screen-with-loud-buzzing-noise
 
In this case, someone with literally the exact same card replaced everything including the mobo and PSU, CPU, etc, and it still did it.
Today,  I decided to try Skyrim again at the "stock" (overclocked) SC speeds; but I turned off the Streamer Service and had Precision running.
 
It crashed at close to 13 mins. :/  I had paused Skyrim at one point, and looked in Precision - the boost clock for this card is 1317 mhz- why was Precision showing it running at 1404? GPU temp was only in the 60s, though.  During the 33 minute session last night at stock speeds, it was still running 1290 boost clock, when stock boost clock is 1178...
 
I'm torn - I don't want to head down the RMA path for a brand new card (and backplate) that's been installed for less than a week since that didn't fix it for others... I'm considering just throwing money at a GTX 980 card that isn't known to suffer from this and returning this one to newegg.. I'll see what EVGA support says.

MightionNY
Yes, but I don't think it's unique to my card; it seems to affect the GTX 970 SC ACX 2.0 specifically. I found this while searching:
http://www.overclock.net/t/1556296/evga-gtx-970-sc-acx-2-0-keeps-crashing-to-black-screen-with-loud-buzzing-noise
 
In this case, someone with literally the exact same card replaced everything including the mobo and PSU, CPU, etc, and it still did it.
Today,  I decided to try Skyrim again at the "stock" (overclocked) SC speeds; but I turned off the Streamer Service and had Precision running.
 
It crashed at close to 13 mins. :/  I had paused Skyrim at one point, and looked in Precision - the boost clock for this card is 1317 mhz- why was Precision showing it running at 1404? GPU temp was only in the 60s, though.  During the 33 minute session last night at stock speeds, it was still running 1290 boost clock, when stock boost clock is 1178...
 
I'm torn - I don't want to head down the RMA path for a brand new card (and backplate) that's been installed for less than a week since that didn't fix it for others... I'm considering just throwing money at a GTX 980 card that isn't known to suffer from this and returning this one to newegg.. I'll see what EVGA support says.

Not sure when you got it, but if not over 30 days the Egg has the 980 Classy's w/ BAK for $550 after rebate, you may be able to just return/exchange. Would work well in that setup for a Few More Dollars.  
 
http://www.newegg.com/Pro..._-14-487-084-_-Product
 

lol, just money, right?  hehe 
it pays to be cool, I mean you have to pay to be cool