Modder Removes Radeon RX 7900 XTX Power Limit And Trades Blows With An RTX 4090

jedi95 watercooled radeon rx 7900 xtx
AMD repeatedly told us (and thus, the world) that the Navi 31 GPU die used in the Radeon RX 7900 XTX was "architected for 3 GHz." That may be true, but in the real world, top-end RDNA 3 parts rarely exceed 2.6 GHz under a sustained, heavy load. As a result, the RX 7900 XTX generally falls behind the GeForce RTX 4090 in game tests.

What if AMD had hit that 3 GHz target, though? What if the cards went even further, perhaps as high as 3.47 GHz? We have the answer to that question thanks to intrepid modder and overclocker /u/jedi95 on Reddit. He attached an Elmor EVC2SE to his ASUS TUF Radeon RX 7900 XTX and used it to remove the power limit altogether, then ran chilled coolant through his full-coverage waterblock.

jedi95 3dmarktimespy comparison
The Radeon has a higher 3DMark score, but that's because Time Spy's CPU test hates Ryzen 9s.

The mods allowed his Radeon to peak at 3,467 MHz in 3DMark Time Spy, with an average GPU clock of 3,333 MHz. That propels his system to an insane 3DMark Time Spy score of 36,971, giving him the fastest all-time score for that GPU in the 3DMark database. He also set records for that GPU in the other 3DMark benchmarks, because nobody else has one of these things modded for unlimited power under 10°C coolant.

For comparison's sake, that's darn close to a 1 GHz overclock. The rated boost clock of a Radeon RX 7900 XTX, according to AMD, is 2.5 GHz, and while most cards will run a little above that in games, you won't see anything like this without a power mod. The card's standard TDP is 355W, and AMD lets you crank that limit up to 430W, but the GPU clearly has so, so much more to give.

jedi95 708w

How much more? Well, during a Time Spy test with no voltage mod, jedi95 recorded a peak power usage of 708 watts using an Elmor Labs PMD-USB. That measures the power draw from the card itself, so it's not a total system power measurement—that's just the Radeon GPU. Lest you think that's not so bad, recall that he's also running a coolant chiller that draws another 500 watts on its own, meaning his GPU is sucking down around 1.2 kW in practice.

cyberpunkbenchmark jedi95
Top is stock, and bottom is with unlocked power limit.

The overclocker only tested 3DMark initially, but at the request of other Redditors, jedi95 ran some game benchmarks on the grossly-overclocked GPU. Call of Duty: Warzone's built-in benchmark sees a 17% gain in performance over the watercooled GPU at stock settings, while Cyberpunk 2077 sees a very slightly smaller 16% gain—although that only takes it from 42.5 FPS to 49.3 FPS with ultra ray-tracing at 2560×1440.

jedi95 3dmark port royal

Indeed, while the 3DMark Time Spy graphics score is in the same range as stock GeForce RTX 4090 cards, the ray-tracing performance still leaves something to be desired. This same user also owns a GeForce RTX 4090, and with that card at its maximum overclock (putting it at 3,090 MHz in this test), it's a cool 40% faster than the hot-clocked Radeon RX 7900 XTX in the 3DMark Port Royal ray-tracing benchmark.

Regardless of the results, it's fascinating to see how easily jedi95 took his Radeon card to such silly speeds. Sure, sticking the card under a full-coverage waterblock pumping chilled coolant is plenty of effort in and of itself, but he says that besides the cooling and power limit mod, only a +30mV offset was required to get these clocks stable. That could bode well for the future of AMD's RDNA 3 architecture—if the company can get power consumption down, we could see some serious screamers out of the red team.