hi ,,
if you are talking about pci latency then its value can be set upto 248 depending on your bios,,
Latency is a value assigned to each device on the PCI bus which determines how long that device may "hold on" to the bus before it must relenquish it to another device which wishes to use it. The value is an integer between 0 and 248. A value of zero means the device will immediately give up the bus if another device wishes to transmit, while a value of 248 means the device will hold on to the bus for the maximum amount of time possible.
Higher values mean that other devices will have to wait longer to be able to use the bus (latency), but will increase the effective bandwidth of the bus due to a reduction in the overhead required to transfer between devices.