AMD Northbridge Fatal Error

I'm not sure when this started happening but it was after I installed some new ram and a new psu. I have only been able to reproduce it consistantly with one game which is halo online. Every other game seems to be random. What happens is, Im just playing a game and suddenly, the screen goes black and restarts the computer. I have tested my ram, no errors on memtest. tested my cpu, no errors. stressed the psu, didnt restart. I dont know what causes it. the only game that does it everytime is Halo Online. Here is what Event Viewer says.

Log Name: System
Source: Microsoft-Windows-WHEA-Logger
Date: 1/17/2016 3:50:04 PM
Event ID: 20
Task Category: None
Level: Error
Keywords:
User: LOCAL SERVICE
Computer: Jeff
Description:
A fatal hardware error has occurred.

Component: AMD Northbridge
Error Source: Machine Check Exception
Error Type: HyperTransport Watchdog Timeout Error
Processor APIC ID: 0

The details view of this entry contains further information.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-WHEA-Logger" Guid="{C26C4F3C-3F66-4E99-8F8A-39405CFED220}" />
<EventID>20</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>0</Task>
<Opcode>0</Opcode>
<Keywords>0x8000000000000000</Keywords>
<TimeCreated SystemTime="2016-01-17T23:50:04.497531500Z" />
<EventRecordID>2616</EventRecordID>
<Correlation ActivityID="{3F22A128-3344-4A28-B43D-A349F23F005D}" />
<Execution ProcessID="1404" ThreadID="2124" />
<Channel>System</Channel>
<Computer>Jeff</Computer>
<Security UserID="S-1-5-19" />
</System>
<EventData>
<Data Name="ErrorSource">3</Data>
<Data Name="ApicId">0</Data>
<Data Name="MCABank">4</Data>
<Data Name="MciStat">0xfe00000000070f0f</Data>
<Data Name="MciAddr">0xfd000000</Data>
<Data Name="MciMisc">0xc00a0fff01000000</Data>
<Data Name="ErrorType">7</Data>
<Data Name="Length">928</Data>
<Data Name="RawData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ata>
</EventData>
</Event>

I have no idea what the xml stuff means. I have tried underclocking my northbrisge and ram but it is still reproducable. help?