LN2 jumper - when switch ?

[Szaquak]

In what case should I use LN2 jumper to switch it ON ?
Is it good to turn on it ?

[Korth]

The LN2 jumper is useful for extreme overclocks which are supercooled with liquid nitrogen (LN2). LN2 pushes component temperatures so far below their intended spec that their semiconductor properties behave differently, the LN2 jumper enables adaptive (self-compensating) isynchronous timing circuitry and a wider tolerance for sensitive supply voltages - it basically runs a different hardware-controlling program in the ROG chip. The LN2 jumper is an invaluable tool for challenging the "cold boot bug" caused by sluggish electron transfer at near absolute zero temperatures, Asus engineered LN2 features into their flagship R5E mobo because they wanted it to feature prominently in overclocking world records.

LN2 is fairly expensive and dangerous stuff which requires special handling. People only use it when attempting to achieve world records, the temperatures involved are very stressful on electronics and will damage or destroy motherboards/processors more often than not. It is used for overclocking only a few minutes at a time, long enough to boot up and run some benchmarks, LN2 is poured directly onto insanely overvolted processors and immediately boils off (sputtering dangerously all over over the place).

If you're planning on operating your motherboard at "room temperature" (that is, the sorts of temperature ranges a normal human could survive) without plugging into large cannisters of superfrozen liquified gas then you should just leave the LN2 jumper disabled. Enabling the jumper will throw off fine timings and voltages as the motherboard attempts to overcompensate for special conditions which are not present.

If you're planning on LN2 overclocking then you really need to do your research, the motherboard requires special preparation and modifications. And you should have a half dozen spare motherboards and processors to kill during your extreme overclocking attempts. Current R5E records can be found here.

[Arne_Saknussemm]

Szaquak wrote:
In what case should I use LN2 jumper to switch it ON ?
Is it good to turn on it ?

Use it if you are connecting the OC panel and want to have access to control certain settings like multiplier etc when overclocking...you would need to install ROG connect plus and update panel to latest firmware...but this is not needed to OC and is a niche usage case...if you don't know what it is for then you don't need it if you know what I mean.

LN2 jumper is not slowmode switch

[Szaquak]

I was thinking of the practical operation of this function during normal operation of your computer. (OC @ 4500 ) In case the temperature in the room 16 at night and 26 during the day switch to change anything ? If so, whether positively or negatively affect such a change for OC.
I know LN2 is no slowmode 😄 i know both function in general. I am asking for details.

Eager and so before leaving I could write briefly and laconically my post 🙂

Thanks for answers and sorry for my English

[Korth]

Critical components on the motherboard are all solid-state semiconductors. Semiconductor chemistry is temperature sensitive, semiconductors have very different electrical properties at LN2 temperatures. The temperature of LN2 is about -196C (77K, -320F) while the operating temperature of motherboard components is (at best) nominally rated for -55C to 125C - LN2 will easily frost hardware far below design thresholds. Consider how sensitive the stability and performance of an overclocked CPU or GPU becomes to temperature, every degree and every microvolt has profound impact once the limits are approached.

Enabling the LN2 jumper activates special timing circuitry which attempts to compensate for altered electrical properties in the VRMs and oscillators. It dramatically changes their power inputs, power outputs, and PWM control frequencies. It makes the onboard ASIC (the ROG chip) run the hardware with a different set of logic and control parameters. It activates the optional onboard temperature probe points. It might "unlock" some BIOS settings or values which would be utterly suicidal at normal temperatures. On some Asus hardware it even powers up resistors designed to add heat to critical areas in the circuit in an attempt to battle the infamous cold bug (because the bootloaders in complex ICs tend to be very stupid and sluggish when they're frozen).

It focusses the motherboard's resources away from general operating efficiency and towards maximal (if momentary) critical component overclocks. It strains the hardware and shortens operating lifespan. It will probably burn out VRMs or cook your processor in a short time, regardless of temps. It also very decisively voids Asus warranty.

Don't enable the LN2 jumper unless you are actually attempting an LN2 overclock. It will not remove any non-LN2 overclocking limits, you're not being held back by anything with the jumper disabled. But enabling it will make your system less stable and will likely cook your mobo/proc quicker (while Asus and Intel categorically disapprove RMAs for such component damage). Even the crazy LN2 overclockers accept the loss of mobos and procs as routine, but they don't just throw them away without at least trying for a blaze of record-breaking glory.

[Szaquak]

Thank you for your comprehensive answer. Well , in my case LN2 remain off ... forever 🙂