Hi cosme7 & Welcome to the forums ^_^,
We consult each others a lot in case of any doubt since this is a public forum
I analysed your latest dump files and in both the cases, there was a Data Read error from the L1 Cache of the processor -
Code:
5: kd> !errrec ffffe0000271b028
===============================================================================
Common Platform Error Record @ ffffe0000271b028
-------------------------------------------------------------------------------
Record Id : 01d06681a9b77d59
Severity : Fatal (1)
Length : 928
Creator : Microsoft
Notify Type : Machine Check Exception
Timestamp : 3/24/2015 22:28:45 (UTC)
Flags : 0x00000000
===============================================================================
Section 0 : Processor Generic
-------------------------------------------------------------------------------
Descriptor @ ffffe0000271b0a8
Section @ ffffe0000271b180
Offset : 344
Length : 192
Flags : 0x00000001 Primary
Severity : Fatal
Proc. Type : x86/x64
Instr. Set : x64
[COLOR=#FF0000][B][U]Error Type : Cache error
Operation : Data Read
[/U][/B][/COLOR]Flags : 0x00
Level : 1
CPU Version : 0x0000000000100fa0
Processor ID : 0x0000000000000005
===============================================================================
Section 1 : x86/x64 Processor Specific
-------------------------------------------------------------------------------
Descriptor @ ffffe0000271b0f0
Section @ ffffe0000271b240
Offset : 536
Length : 128
Flags : 0x00000000
Severity : Fatal
Local APIC Id : 0x0000000000000005
CPU Id : a0 0f 10 00 00 08 06 05 - 09 20 80 00 ff fb 8b 17
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
Proc. Info 0 @ ffffe0000271b240
===============================================================================
Section 2 : x86/x64 MCA
-------------------------------------------------------------------------------
Descriptor @ ffffe0000271b138
Section @ ffffe0000271b2c0
Offset : 664
Length : 264
Flags : 0x00000000
Severity : Fatal
[COLOR=#FF0000][B][U]Error : DCACHEL1_DRD_ERR (Proc 5 Bank 0)
[/U][/B][/COLOR] Status : 0xb635c00000000135
Address : 0x000000010244ece0
Misc. : 0x0000000000000000
Now, the error occurred in the Processor #5 and Bank #0. This is consistent with other dump as well. Since you have already performed the diagnostics and are also receiving the errors in them, I would advise you to get a new CPU or send this CPU for replacement if it is still under warranty. Please buy the CPU from a shop that accepts returns so that in case the problem is not the CPU (Very, very minor chance), you could get your money back.
Now, I think that the only case in which the motherboard needs to be replaced would be when one of the pins of the socket in which CPU is inserted in the motherboard is damaged. But, the CPU being bad is more likely. If the motherboard was really at fault, I think that we would have seen loads of other types of bugchecks instead of only 0x124 (WHEA_UNCORRECTABLE_ERROR).
I hope this helps Mihael
-Pranav