Overclocking graphics cards is quite different from how “OC” works on CPUs. GPUs generally operate at fairly low voltages and clock speeds, and their overclocking is mostly artificially limited by various power or voltage limits in the drivers and firmware. The same is true of Nvidia’s current cards. But the artificial OC limits have now been bypassed, so it may be possible to extract significantly higher performance from them, although not without risks.
Nvidia graphics cards typically have a maximum TGP value set, which is the power consumption limit applicable when overclocking the graphics card and which users normally cannot increase. When overclocking, it is often precisely this limit that prevents further performance increases. To overcome it, so-called shunt mods are performed, which alter the resistance of the resistors used by the GPU to determine power consumption, making the chip believe that its power consumption is lower than it actually is and allowing the power management system to run at higher clock speeds. However, such a hardware modification is a serious and risky matter. At the very least, you will lose your warranty.
Now, however, there is a way to bypass the overclocking limits on GeForce RTX 5000 graphics cards without any hardware modification. Version 0.36 of the mVolt+ application has now made previously unavailable configuration options accessible, including settings for power limits and voltage levels for Core (the compute units themselves), XBAR (interconnect), SYS, and Video domains.
Using these settings, GPUs can be overclocked to higher levels of performance (but also higher power consumption) than allowed by the standard limits. For example, a user with an Asus ROG Astral GeForce RTX 5080 OC has reportedly managed to increase its power consumption from the standard maximum TGP of 450 W to as much as 680 W (in FurMark), while GeForce RTX 5090 graphics cards can reportedly be pushed to power consumption levels of around 700 W.
New Driver Updates May Block mVolt+
It is not yet clear whether you will be able to keep using this way of torturing your graphics cards. Nvidia now appears to have blocked these capabilities in the new GeForce graphics drivers (615.56). With these drivers, attempts to bypass the power limits using this tool result in a crash (or perhaps an intentional driver reset, even?) resulting in a black screen.
Given that the motivation behind OC limitations is not simple hostility towards the buyer on the part of the GPU vendor, but also an effort to prevent users from destroying their GPUs, it makes sense for Nvidia to attempt to secure the newly discovered overclocking loopholes again. It is difficult to say for now whether the developers of mVolt+ or other applications will manage to unlock these overclocking options again, or whether they will remain out of reach in the future. Users fighting for every percentage point of performance have the option ot install older drivers from before version 615.56 and stay on them for as long as possible, however.
The ability to use this application appears to have enabled higher overclocking scores in various benchmarks, but the actual benefit in games may be smaller. And users are of course risking not only instability of their graphics card after overclocking, but also hardware damage—the use of higher voltages in particular can be risky. Only highly experienced users who first study the tool’s capabilities and for whom it would not be a problem if they “fry” their GPU should attempt to use these options.
Beware of 12V-2×6 Connectors
And increasing power consumption in general will only exacerbate an existing weakness of RTX 5000-generation graphics cards: These graphics cards already tend to have problems with their 12V-2×6 power connectors melting due to their inadequate safety. This could be particularly problematic with the GeForce RTX 5090, where a further increase in power consumption when using mVolt+ could be an issue. Melting or burning connectors can affect these cards even at their specified maximum load without overclocking, so if you exceed that limit with power consumption of, say, 700 W, connector temperatures and the risk of pins burning and the plastic melting in the event of an imperfect contact will increase even further.
And it will not be a problem only with the RTX 5090—if you push power consumption to 600 W or more on an RTX 5070 Ti or RTX 5080, like the user mentioned above had, you will face exactly the same risk of melting as with an RTX 5090 when it is drawing that much power.
So if you were to overclock a card with just one 12V-2×6 connector (which is the overwhelming majority), you should probably use one of the cables that provide some overheating protection. Even that is not a guarantee, however, because it has already been shown that this does not necessarily reliably prevent problems either.
Sources: mVolt+, techPowerUp, VideoCardz
English translation and edit by Jozef Dudáš
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