I have the following setup:

1 256GB SSD / Win8-Ubuntu 13.04 UEFI Dualboot
2x1TB in RAID 1 (Detected and working)
2x4TB in RAID 1 (Not Detected not showing up in /dev/mapper)

The problem is that I just recently added another two drives that are 4TB in RAID 1 but they aren't detected in Ubuntu as one drive.

I know it works because Windows detected my new 4TB RAID 1 just fine, here's a screenshot via one of the raid disk utilities that came with my motherboard (fakeraid).

fdisk -l

Disk /dev/sda: 256.1 GB, 256060514304 bytes
255 heads, 63 sectors/track, 31130 cylinders, total 500118192 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0a7f44fd

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1   500118191   250059095+  ee  GPT

WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

WARNING: GPT (GUID Partition Table) detected on '/dev/sdc'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdc doesn't contain a valid partition table

WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sdd: 4000.8 GB, 4000787030016 bytes
255 heads, 63 sectors/track, 486401 cylinders, total 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sdd doesn't contain a valid partition table

WARNING: GPT (GUID Partition Table) detected on '/dev/sde'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sde: 4000.8 GB, 4000787030016 bytes
255 heads, 63 sectors/track, 486401 cylinders, total 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sde doesn't contain a valid partition table

WARNING: GPT (GUID Partition Table) detected on '/dev/mapper/ddf1_TeraRAID'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/mapper/ddf1_TeraRAID: 1000.1 GB, 1000120999936 bytes
255 heads, 63 sectors/track, 121591 cylinders, total 1953361328 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

                    Device Boot      Start         End      Blocks   Id  System
/dev/mapper/ddf1_TeraRAID1               1  1953361327   976680663+  ee  GPT

Disk /dev/mapper/ddf1_TeraRAID1: 134 MB, 134217728 bytes
255 heads, 63 sectors/track, 16 cylinders, total 262144 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000040

Disk /dev/mapper/ddf1_TeraRAID1 doesn't contain a valid partition table

Disk /dev/mapper/ddf1_TeraRAID2: 998.9 GB, 998911246336 bytes
255 heads, 63 sectors/track, 121444 cylinders, total 1950998528 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x73736572

This doesn't look like a partition table
Probably you selected the wrong device.

                      Device Boot      Start         End      Blocks   Id  System
/dev/mapper/ddf1_TeraRAID2p1      1920221984  3736432267   908105142   72  Unknown
/dev/mapper/ddf1_TeraRAID2p2   ?  1936028192  3889681299   976826554   6c  Unknown
/dev/mapper/ddf1_TeraRAID2p3   ?           0           0           0    0  Empty
/dev/mapper/ddf1_TeraRAID2p4        27722122    27722568         223+   0  Empty

Disk /dev/mapper/ddf1_TeraRAID3: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 cylinders, total 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/ddf1_TeraRAID3 doesn't contain a valid partition table

blkid

/dev/sda1: LABEL="Recovery" UUID="0AE412DFE412CD37" TYPE="ntfs" 
/dev/sda2: UUID="0613-84B4" TYPE="vfat" 
/dev/sda4: UUID="3A1214B712147A59" TYPE="ntfs" 
/dev/sda5: UUID="dbb033df-b455-41c5-a050-d6aa816462a1" TYPE="ext4" 
/dev/sda6: UUID="8577fdea-9aef-4789-b62e-86100019d2e1" TYPE="swap" 
/dev/sdb: TYPE="ddf_raid_member" 
/dev/sdc: TYPE="ddf_raid_member" 
/dev/mapper/ddf1_TeraRAID2: LABEL="TeraRAID" UUID="202E91BF2E918E82" TYPE="ntfs" 
/dev/mapper/ddf1_TeraRAID3: LABEL="RandomStuff" UUID="00eea61f-86f3-46fb-bd66-07da8355a2f4" TYPE="ext4"

My 4TB drives /dev/sdd and /dev/sde should be recognized as ddf_raid_member but they're nowhere to be found here...

blkid -p /dev/sdd

this command gives no output

dmraid -ay -vvv -d

    WARN: locking /var/lock/dmraid/.lock
WARN: missing dm serial file for /dev/dm-0
WARN: missing dm serial file for /dev/dm-1
WARN: missing dm serial file for /dev/dm-2
WARN: missing dm serial file for /dev/dm-3
NOTICE: /dev/dm-3: asr     discovering
NOTICE: /dev/dm-3: ddf1    discovering
NOTICE: /dev/dm-3: hpt37x  discovering
NOTICE: /dev/dm-3: hpt45x  discovering
NOTICE: /dev/dm-3: isw     discovering
DEBUG: not isw at 1073740800
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 1072658944
NOTICE: /dev/dm-3: jmicron discovering
NOTICE: /dev/dm-3: lsi     discovering
NOTICE: /dev/dm-3: nvidia  discovering
NOTICE: /dev/dm-3: pdc     discovering
NOTICE: /dev/dm-3: sil     discovering
NOTICE: /dev/dm-3: via     discovering
NOTICE: /dev/dm-2: asr     discovering
NOTICE: /dev/dm-2: ddf1    discovering
NOTICE: /dev/dm-2: hpt37x  discovering
NOTICE: /dev/dm-2: hpt45x  discovering
NOTICE: /dev/dm-2: isw     discovering
DEBUG: not isw at 998911245312
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 998910163456
NOTICE: /dev/dm-2: jmicron discovering
NOTICE: /dev/dm-2: lsi     discovering
NOTICE: /dev/dm-2: nvidia  discovering
NOTICE: /dev/dm-2: pdc     discovering
NOTICE: /dev/dm-2: sil     discovering
NOTICE: /dev/dm-2: via     discovering
NOTICE: /dev/dm-1: asr     discovering
NOTICE: /dev/dm-1: ddf1    discovering
NOTICE: /dev/dm-1: hpt37x  discovering
NOTICE: /dev/dm-1: hpt45x  discovering
NOTICE: /dev/dm-1: isw     discovering
DEBUG: not isw at 134216704
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 133134848
NOTICE: /dev/dm-1: jmicron discovering
NOTICE: /dev/dm-1: lsi     discovering
NOTICE: /dev/dm-1: nvidia  discovering
NOTICE: /dev/dm-1: pdc     discovering
NOTICE: /dev/dm-1: sil     discovering
NOTICE: /dev/dm-1: via     discovering
NOTICE: /dev/dm-0: asr     discovering
NOTICE: /dev/dm-0: ddf1    discovering
NOTICE: /dev/dm-0: hpt37x  discovering
NOTICE: /dev/dm-0: hpt45x  discovering
NOTICE: /dev/dm-0: isw     discovering
DEBUG: not isw at 1000120998912
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 1000119917056
NOTICE: /dev/dm-0: jmicron discovering
NOTICE: /dev/dm-0: lsi     discovering
NOTICE: /dev/dm-0: nvidia  discovering
NOTICE: /dev/dm-0: pdc     discovering
NOTICE: /dev/dm-0: sil     discovering
NOTICE: /dev/dm-0: via     discovering
NOTICE: /dev/sde: asr     discovering
NOTICE: /dev/sde: ddf1    discovering
NOTICE: /dev/sde: hpt37x  discovering
NOTICE: /dev/sde: hpt45x  discovering
NOTICE: /dev/sde: isw     discovering
DEBUG: not isw at 4000787028992
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 4000785947136
NOTICE: /dev/sde: jmicron discovering
NOTICE: /dev/sde: lsi     discovering
NOTICE: /dev/sde: nvidia  discovering
NOTICE: /dev/sde: pdc     discovering
NOTICE: /dev/sde: sil     discovering
NOTICE: /dev/sde: via     discovering
NOTICE: /dev/sdd: asr     discovering
NOTICE: /dev/sdd: ddf1    discovering
NOTICE: /dev/sdd: hpt37x  discovering
NOTICE: /dev/sdd: hpt45x  discovering
NOTICE: /dev/sdd: isw     discovering
DEBUG: not isw at 4000787028992
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 4000785947136
NOTICE: /dev/sdd: jmicron discovering
NOTICE: /dev/sdd: lsi     discovering
NOTICE: /dev/sdd: nvidia  discovering
NOTICE: /dev/sdd: pdc     discovering
NOTICE: /dev/sdd: sil     discovering
NOTICE: /dev/sdd: via     discovering
NOTICE: /dev/sdc: asr     discovering
NOTICE: /dev/sdc: ddf1    discovering
WARN: ddf1: bad secondary header signature 5ac9b538 on /dev/sdc
NOTICE: /dev/sdc: ddf1 metadata discovered
NOTICE: /dev/sdc: hpt37x  discovering
NOTICE: /dev/sdc: hpt45x  discovering
NOTICE: /dev/sdc: isw     discovering
DEBUG: not isw at 1000204884992
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 1000203803136
NOTICE: /dev/sdc: jmicron discovering
NOTICE: /dev/sdc: lsi     discovering
NOTICE: /dev/sdc: nvidia  discovering
NOTICE: /dev/sdc: pdc     discovering
NOTICE: /dev/sdc: sil     discovering
NOTICE: /dev/sdc: via     discovering
NOTICE: /dev/sdb: asr     discovering
NOTICE: /dev/sdb: ddf1    discovering
WARN: ddf1: bad secondary header signature b7875558 on /dev/sdb
NOTICE: /dev/sdb: ddf1 metadata discovered
NOTICE: /dev/sdb: hpt37x  discovering
NOTICE: /dev/sdb: hpt45x  discovering
NOTICE: /dev/sdb: isw     discovering
DEBUG: not isw at 1000204884992
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 1000203803136
NOTICE: /dev/sdb: jmicron discovering
NOTICE: /dev/sdb: lsi     discovering
NOTICE: /dev/sdb: nvidia  discovering
NOTICE: /dev/sdb: pdc     discovering
NOTICE: /dev/sdb: sil     discovering
NOTICE: /dev/sdb: via     discovering
NOTICE: /dev/sda: asr     discovering
NOTICE: /dev/sda: ddf1    discovering
NOTICE: /dev/sda: hpt37x  discovering
NOTICE: /dev/sda: hpt45x  discovering
NOTICE: /dev/sda: isw     discovering
DEBUG: not isw at 256060513280
DEBUG: isw trying hard coded -2115 offset.
DEBUG: not isw at 256059431424
NOTICE: /dev/sda: jmicron discovering
NOTICE: /dev/sda: lsi     discovering
NOTICE: /dev/sda: nvidia  discovering
NOTICE: /dev/sda: pdc     discovering
NOTICE: /dev/sda: sil     discovering
NOTICE: /dev/sda: via     discovering
DEBUG: _find_set: searching .ddf1_disks
DEBUG: _find_set: not found .ddf1_disks
DEBUG: _find_set: searching ddf1_TeraRAID
DEBUG: _find_set: searching ddf1_TeraRAID
DEBUG: _find_set: not found ddf1_TeraRAID
DEBUG: _find_set: not found ddf1_TeraRAID
NOTICE: added /dev/sdc to RAID set ".ddf1_disks"
DEBUG: _find_set: searching .ddf1_disks
DEBUG: _find_set: found .ddf1_disks
DEBUG: _find_set: searching ddf1_TeraRAID
DEBUG: _find_set: searching ddf1_TeraRAID
DEBUG: _find_set: found ddf1_TeraRAID
DEBUG: _find_set: found ddf1_TeraRAID
NOTICE: added /dev/sdb to RAID set ".ddf1_disks"
DEBUG: checking ddf1 device "/dev/sdb"
DEBUG: checking ddf1 device "/dev/sdc"
DEBUG: set status of set "ddf1_TeraRAID" to 16
DEBUG: set status of set ".ddf1_disks" to 16
RAID set "ddf1_TeraRAID" already active
INFO: Activating GROUP raid set ".ddf1_disks"
NOTICE: discovering partitions on "ddf1_TeraRAID"
NOTICE: /dev/mapper/ddf1_TeraRAID: dos     discovering
WARN: unlocking /var/lock/dmraid/.lock
DEBUG: freeing devices of RAID set "ddf1_TeraRAID"
DEBUG: freeing device "ddf1_TeraRAID", path "/dev/sdb"
DEBUG: freeing device "ddf1_TeraRAID", path "/dev/sdc"
DEBUG: freeing devices of RAID set ".ddf1_disks"
DEBUG: freeing device ".ddf1_disks", path "/dev/sdc"
DEBUG: freeing device ".ddf1_disks", path "/dev/sdb"

fstab

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda5 during installation
UUID=dbb033df-b455-41c5-a050-d6aa816462a1 /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda2 during installation
#UUID=0613-84B4  /boot/efi       vfat    defaults        0       1
# swap was on /dev/sda6 during installation
UUID=8577fdea-9aef-4789-b62e-86100019d2e1 none            swap    sw              0       0
UUID=0613-84B4  /boot/efi   vfat    defaults    0   1

How can I get Ubuntu to recognize my newly made 4TB RAID 1?

Fakeraid on dual-boot is kind of a nightmare. You'll likely be better off with mdraid than dmraid on the Ubuntu side, but it will still take a bit of work. Here's a[n archived] link to a good set of tips from someone who was able to sort it out for Ubuntu 12.10 and Win7 x64.