prime 95 error on xmp and CPU-auto

[stonerockbato]

Just got 2 systems built, same.
Rampage IV Extreme
Bios updated to recent (current available v. now)

Both with Vengeance 32GB x2 (CMZ32GX3M4X1600C10)
Whenever I do XMP, set to 1600, prime 95 errors or BSOD
And when I do CPU - auto (sets CPU max to 4400), prime 95 errors or BSOD

Why is this?
I have another setup with same but it runs well with both (tested blend for 7 hours)
Does that mean the other unit has a possible bad component? MB, CPU, RAM?
Or the settings are just not accepted?

I'll be doing more testing by bringing everything to stock and see if it fails (CPU - auto and/or XMP)
And do small ffts, large, and blend...and see where it fails
And probably switch components around but I'd like to get more insights on this as I go

Thank you.

[Necrosan]

Set RAM voltage manually and see if that fixes it.
You may also need to bump VCCSA and/or connect your EZ_PLUG2 connector.

[8_Pack]

Try resetting bios, F5 ,F10 restart. XMP, Rampage tweak mode 1, VCCSA 1.25, VTT 1.25 and DRAM voltage 1.65. Test this using mem test. Then in windows. If it stable work on lowering VCCSA and VTT , if its unstable mem test one stick at a time on the same settings.

Post back how this goes.

[stonerockbato]

finally got it to work and run prime for 9.5 hours w/o problems/errors
plugged in ez-plug2
and had to up vcore to 1.275, 1.260 BSOD...planning to lower it a bit to see if it works

Wow, some difference there.
both 3820
1st setup with XMP to 1600
100X44 (realcore running at 100x33)
1.25V
DRAM V 1.5
ez-plug2 unused
all else auto...

while 2nd unit
won't work on xmp to 1600 (ez-plug worked), 1.5V
then 1.1275 instead

1st unit seems easier and more stable w/ lower Voltage
2nd unit seems to fail more...

Any suggestions as to increase bCLK, lowering multiplier (should be better than just 100X44)?
but somehow below 1.13V?
Somehow I don't feel pleased with the CPU on 2nd unit though
And why 1st unit works well plus and w/o plug2 used, hard to wire it as the tower is huge and to wire it almost midway to MB
Is this normal at all or just got really lucky with the 1st setup?

[HiVizMan]

No two CPU's will behave the same, that is just how it is.

As to which is better or less stress on your processor, multi is the better option.