2.5 In your timings:
CAS Latency Time
This refers to the Column Address Strobe delay time. Lower is better! However, in a P4 system, lowering this setting only improves performance minimally, so it might be better to increase this setting to gain stability or a higher overclock.
2nd digit in your timings (3):
DRAM RAS# to CAS# Delay
This refers to the Row Address Strobe to Column Address Strobe delay time. Lower is better! This is the most crucial setting in a P4 system! Lowering this setting improves performance quite noticeably, so you might want to sacrifice some clockspeed to lower this timing.
3rd digit in your timings (3):
DRAM RAS# Precharge
This refers to the Row Address Strobe to Column Address Strobe delay time. Lower is better! This is the 2nd most crucial setting in a P4 system! Lowering this setting improves performance quite noticeably, so you might want to sacrifice some clockspeed to lower this timing.
4th Digit in your timings (7):
Act to Precharge Delay
This refers to the Active to Precharge delay time. Lower is better! However, same as above, lowering this setting only improves performance minimally, so it might be better to increase this setting to gain stability or a higher overclock.
All taken from the site in the post above, but basically it deals with overclocking alot.