It is not safe when you have reached TJMax of 105C and the CPU frequency should be throttled down hence it is not really a successful OC.
Try lower speed like 4.1-4.2GHz to reduce the temp.
The RAM issue, you should try setting AI OC Tuner to XMP profile #1 or #2, at rated default specs.

You could try to play with vdimm, VCCIO, VCCSA (if any). Increase or decrease them might help.

Other than that I'm afraid to say that probably you got a bad stick of RAM. Try other RAM on your PC or put the current RAM on another machine (friend's).

This board should have no issue with CAS6.
Could be your chip's IMC cant keep up with too tighten CAS.
Try increase vdimm 1.6-1.65v, VCCIO 1.2v, VCCSA 1.2v
Try 1600 7-8-8-24 or 8-8-8-24
Try 1866 8-8-8-24 or 9-9-9-28
Try 2133 9-10-9-28 or 9-11-9-28

But you're not alone, another GUY also having issue with this RAM. But his 4 sticks.

I can't tell you how much voltage to add or reduce because I don't own the RAM kit, unfortunately
All you have to do is try & error.

Well done mate.
By rights for 8 threads proc like 3770K, you should have 8 screens of memtest, so that CPU usage recorded in Task Manager is 100%.
Let say your free mem shown in Task Manager is 7GB, so mem to run per memtest is 7/8 = 0.875GB (~875MB)

Well done! 
Glad that you got the bad stick sorted out.

Nice effort! Actually memtest 500% is more than enough already.
It is stressful to RAM but for CPU stability always test with Prime95/LinX/IBT.
Good luck

Very nice! So now you are running single channel RAM (single stick only) ?

Hi guys, what is tRFC (Refresh Cycle Time)setting? where do i change the setting? how do i determine i insert a correct timing for overclock the ram?

The low GFlops might be due to single channel RAM. Looks handicap and performs like old days Pentium dual core.

Yes definitely you should retest later.
Of course dual channel is more difficult to pass stability tests and need to tweak again the settings voltages etc. It's all different now. Good luck!

What cpu cooler are u using? Ur cpu temp is kind of high.

wow taikor u let ur cpu go up to 104 deg??

 

also why is core temp showing diff freq from cpuz?

I bought 8 pcs of 3770K's in total.
Now 2 units left.

I seldom share the picture of my rig setup here. So here you go...