Sudden reboot under load.

Dear all,

It is my first time writing on this forum. I bought a pre assembled desktop pc to which I added a second hand graphic card. The relevant specs are: CPU: intel 8700K, GPU: msi armor gtx 1080ti, RAM: 16 GB, PSU: 650W gold rated. The GPU drivers are the latest from NVIDIA 416.81. I was not pleased with the performance or noise of the stock cooler of the GPU, so I attached a Arctic accelero 4 cooler on it. Unfortunately I did not realize mine is an extended PCB (have not dealt with desktops in a long time) and is not supported by the cooler. The die cooler is properly pasted and working, but the back-plate supposed to cool the other components could not be fastened properly. So I made an half hack by adding some heath sinks to the exposed VRM and VRAM chips under the cooler.

The computer works normally and can play light games, but when I try something heavy, like the new tomb rider or the Witcher 3, it shuts down after a while, order of 10 minutes. It does not produce graphical artifacts or performance dips, solid 60 fps at 4K, the PC just suddenly reboots. The core temps look very ok: 50 C for the GPU and something 60 for the CPU, fans are blowing.

How to I know f it is the VRAM overheating and not something else like the power supplier? Did I damage something permanently or I can save it reinstalling the old cooler?

Note that I run some CUDA codeand I can allocate up to 99% of the free memory (so around 10.4 GB removing what is used by the display), and write/read to it with a bandwidth of around 8.5 GB/s, so the VRAM seems to still be there.

I am more of a software than hardware dude, so any help to analyze or solve the situation will be very much appreciated! Cheers!

EDIT: int the event log, the failure is reported as this critical error:

Log Name: System

Source: Microsoft-Windows-Kernel-Power

Date: 18/11/2018 21:45:08

Event ID: 41

Task Category: (63)

Level: Critical

Keywords: (70368744177664),(2)

User: SYSTEM

Computer: DESKTOP-TRR31LG

Description:

The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

Event Xml:

<Event xmlns="http://schemas.microsoft.com/win/2004/08...>

<System>

<Provider Name="Microsoft-Windows-Kernel-Power" Guid="{331C3B3A-2005-44C2-AC5E-77220C37D6B4}" />

<EventID>41</EventID>

<Version>6</Version>

<Level>1</Level>

<Task>63</Task>

<Opcode>0</Opcode>

<Keywords>0x8000400000000002</Keywords>

<TimeCreated SystemTime="2018-11-18T20:45:08.191914400Z" />

<EventRecordID>3941</EventRecordID>

<Correlation />

<Execution ProcessID="4" ThreadID="8" />

<Channel>System</Channel>

<Computer>DESKTOP-TRR31LG</Computer>

<Security UserID="S-1-5-18" />

</System>

<EventData>

<Data Name="BugcheckCode">0</Data>

<Data Name="BugcheckParameter1">0x0</Data>

<Data Name="BugcheckParameter2">0x0</Data>

<Data Name="BugcheckParameter3">0x0</Data>

<Data Name="BugcheckParameter4">0x0</Data>

<Data Name="SleepInProgress">0</Data>

<Data Name="PowerButtonTimestamp">0</Data>

<Data Name="BootAppStatus">0</Data>

<Data Name="Checkpoint">0</Data>

<Data Name="ConnectedStandbyInProgress">false</Data>

<Data Name="SystemSleepTransitionsToOn">1</Data>

<Data Name="CsEntryScenarioInstanceId">0</Data>

<Data Name="BugcheckInfoFromEFI">false</Data>

<Data Name="CheckpointStatus">0</Data>

</EventData>

</Event>