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OSPF changes the dead-interval (to 4 times hello) whenever the hello-interval changes, but not vice versa.
You can configure subsecond hello intervals also. I have listed the commands below which will set hello/dead to 5/10 and 250ms/1 sec.

int s0/0/0
 ip ospf hello-interval 5
 ip ospf dead-interval 7
!
int s0/1/0
 ip ospf dead-interval minimal hello-interval 4

Remember that hello timers must match in order to form an adjacency.

R5#sh ip ospf int s0/0/0
Serial0/0/0 is up, line protocol is up
  Internet Address 155.1.0.5/24, Area 0
  Process ID 1, Router ID 150.1.5.5, Network Type POINT_TO_MULTIPOINT, Cost: 64
  Enabled by interface config, including secondary ip addresses
  Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT
  Timer intervals configured, Hello 5, Dead 7, Wait 7, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:04
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/4, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 12
  Last flood scan time is 0 msec, maximum is 4 msec
  Neighbor Count is 4, Adjacent neighbor count is 4
    Adjacent with neighbor 150.1.1.1
    Adjacent with neighbor 150.1.3.3
    Adjacent with neighbor 150.1.4.4
    Adjacent with neighbor 150.1.2.2
  Suppress hello for 0 neighbor(s)

R5#sh ip ospf int s0/1/0
Serial0/1/0 is up, line protocol is up
  Internet Address 155.1.45.5/24, Area 0
  Process ID 1, Router ID 150.1.5.5, Network Type POINT_TO_POINT, Cost: 64
  Enabled by interface config, including secondary ip addresses
  Transmit Delay is 1 sec, State POINT_TO_POINT
  Timer intervals configured, Hello 250 msec, Dead 1, Wait 1, Retransmit 5
    oob-resync timeout 40
    Hello due in 61 msec
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 2/5, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 8
  Last flood scan time is 0 msec, maximum is 4 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 150.1.4.4
  Suppress hello for 0 neighbor(s)

http://www.cisco.com/en/US/customer/docs/ios/iproute/configuration/guide/irp_ospf_fast_hello_ps6350_TSD_Products_Configuration_Guide_Chapter.html