Trying to find a solution to the crashes.

Hello all,
I first want to say, thank you for your time reading this, with that said I must start for the beginning. As of this new year, I reacently updated my graphics card in my desktop, (all system infomation will be listed at the bottom) surpried to see the new benchmark my system could reached,I began to run new games on Ultra high settings with no problems (farcry3, batman arkham city). One night after watching a movie, I decided to play an old game with friends (league of legends..yes I know) and set the setting to high, because its not too graphically demanding to run. With in 20 mins I noticed the screen colors blurr then snap back into focuse, and then without warning my screen blacks out and a loud screech blasted through my speakers. The computer itself never shut off but on reboot, at the bios screen a message appeared saying system crashed from a "Hyper transport sync flood error". I continued on and upon entering my profile I recieved this message:

Problem Event Name: BlueScreen
OS Version: 6.1.7601.2.1.0.256.1
Locale ID:
Additional information about the problem:
BCCode: 124
BCP1: 0000000000000000
BCP2: FFFFFA8007D70038
BCP3: 0000000000000000
BCP4: 0000000000000000
OS Version: 6_1_7601
Service Pack: 1_0
Product: 256_1

Not knowing what caused this problem, I started out tracking down this any thing about it on many different forms. Some said It was from drives, So I updated any out of date drives and reinstalled my graphics card's drivers.I then proceded to booted up farcry3 ...no problems..later that weekend played LoL system crashes twice... same error reports both times as above. I want back to the forms to check again. other said you might need to update bios (which I dont clam to be an extreme computer whiz but bios updates are alittle intimidate do to the fact I could turn my computer into a large paper weight). so I looked for another less terrifying solution. Some said the error could come from low CPU frequency. Which I then turned to myself and said how do I increase it?
going in circle and a bit lost at the fact I can run some demanding games on higher settings and other less demanding ones crash my system. (I try not to play these games to prevent any damage to my new graphics card) I am trying to find a solution where I can fix this problem and be done with it.
Please help and Thank you once again.

System Information:

Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120830-0333)
Language: English (Regional Setting: English)
System Manufacturer: Asus
System Model: M4A78T-E
BIOS: BIOS Date: 06/05/09 10:06:42 Ver: 08.00.15
Processor: AMD Phenom(tm) II X4 955 Processor (4 CPUs), ~3.2GHz
Memory: 8192MB RAM
Available OS Memory: 8190MB RAM
Page File: 3475MB used, 12902MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled

Card name: AMD Radeon HD 7800 Series
Manufacturer: Advanced Micro Devices, Inc.
Chip type: AMD Radeon Graphics Processor (0x6819)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_6819&SUBSYS_23201787&REV_00
Display Memory: 1772 MB
Dedicated Memory: 2029 MB
Shared Memory: 3839 MB
Current Mode: 1360 x 768 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: LG TV
Monitor Id: GSM0001
Native Mode: 1360 x 768(p) (60.015Hz)
Output Type: HDMI


Card name: AMD Radeon HD 7800 Series
Manufacturer: Advanced Micro Devices, Inc.
Chip type: AMD Radeon Graphics Processor (0x6819)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_6819&SUBSYS_23201787&REV_00
Display Memory: 1772 MB
Dedicated Memory: 2029 MB
Shared Memory: 3839 MB
Current Mode: 1920 x 1200 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: SyncMaster
Monitor Id: SAM0587
Native Mode: 1920 x 1200(p) (59.950Hz)
Output Type: Displayport External
(there are two of them)