![\"\"](\"http:\/\/mygaming.co.za\/news\/wp-content\/uploads\/2012\/01\/enermax-galaxy-1000w.jpg\" "\\"enermax-galaxy-1000w\\"")
<\/a>Enermax Galaxy 1000w<\/p><\/div>\n
Why rails are split up<\/h3>\n
A 12v source in a PSU is split into multiple rails for safety reasons. They are meant to limit the amount of current that can be drawn on specific cables, to prevent cable burn and shorting – similar to how a circuit breaker in a house works. The original guideline in the Intel ATX standard required that no more than 20 amperes can be provided over one rail in a PSU. However, Intel changed the wording of the ATX standard in 2007 from required to recommended, meaning power supplies can now sport multiple rails rated at over 20 amperes each.<\/p>\n
Marketing myths<\/h3>\n
\u201cMultiple rails provide cleaner, more stable voltage.\u201d<\/strong><\/p>\n This is not the case, as the circuitry used to split the rails has no form of conditioning or filtering stages to improve \u201ccleaner\u201d power. ‘More stable’ is subjective – in most cases, splitting load from various sources such as the GPU, CPU and hard drives across multiple rails will lessen the risk of supply instability thanks to limits set by the rail circuitry.<\/p>\n \u201cSingle rail PSU\u2019s are more powerful.\u201d<\/strong><\/p>\n This is not the case. A single rail PSU simply negates the circuitry needed to split rails. The benefit of this is that balancing load across rails is not an issue, as all 12v devices plugged into the rail can draw as much power as they need (until the single rail is overloaded). That being said, single 12v rail PSU\u2019s do not offer better voltage regulation, nor do they offer better ripple filtering unless the single rail power supply is a higher quality unit than the multi rail PSU it is being compared with.<\/p>\n