Explanation of RMi's New Type 4 Cables

By Jonny Gerow, on July 24, 2015

The Corsair RMi Series is our newest line of PC power supplies and the reviewers can't say enough good things about it!

One of the biggest compliments we received about the RMi is how low the ripple is under load. Tony Day of JonnyGURU.com measured only 11mV of ripple on the +12V rail of an RM750i at full load. And Aris Mpitziopoulos of TechPowerUp! measured only 17.5mV of ripple on the +12V rail of an RM1000i.

Screenshot from the oscilloscope used during the JonnyGURU.com review of the RM750i

This improved ripple suppression is a direct result of the Type 4 cables included with the RMi Series power supplies. The Type 4 cables have the same pin-out as Type 3 cables, but include small, solid capacitors on the +12V, +5V and +3.3V leads on the 24-pin, PCIe and EPS12V cables.

Without these capacitors, ripple is still very acceptable; being as high as 25mV with a full load on the +12V rail of an RM1000i. This is exhibited on the HX1000i, which uses the same technologies as the RMi, but does not come with the Type 4 cables.

The 24-pin of the Type 4 cable set also has a unique feature not implemented in the standard Type 3 cables. There are a total of 28-pins where the cable plugs into the PSU's modular interface, instead of the usual 24-pins. The extra four pins are "sense wires". While a +3.3V sense is part of the ATX standard and is found on most PSUs, it is not often implemented. The RMi not only utilizes the +3.3V sense on the ATX connector, but also utilizes an additional +12V sense and +5V sense. These sense wires read the voltages at the load (the end of the cable) and can increase voltage automatically if voltages drop.

The combination of these two improvements made to the RMi's cable set contributes to the exceptional voltage regulation and ripple suppression all of our customers and the reviewers have been talking about.


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