AMD Radeon RX 7900 XTX & 7900 XT Review: RDNA 3 Brings Big Gains
With the tuning options built into AMD's driver suite, users have multiple ways to tweak a Radeon RX 7900 series' performance. Users can manually alter frequencies, voltages, fan speeds, and the max power target using percentages or finer-grained numerical sliders, or users can opt to use various preset modes or auto-tune a number of characteristics, including GPU and memory frequencies as well as the GPU voltage, including under-volting.
Radeon RX 7900 XTX Default Settings Hardware Health Data
With older Radeons, a single sensor had been used to determine the GPU temperature, and data from that lone sensor was used to control the card's thermal profile. With newer RDNA 2 and RDNA 3 GPUs, like the Navi 31 powering the Radeon RX 7900 series, AMD has incorporated a network of multiple thermal sensors at strategic locations across the die. Data gathered from the sensors is used to determine what AMD calls the "Junction Temperature", and it's the Junction Temperature that is used to tune the card's power and thermal profiles (the Junction Temperature is effectively the hottest part of the GPU die at any given time). AMD claims the increased resolution and accuracy from multiple thermal sensors allows it to increase overall sustained performance, because throttling based on the Junction Temperature is more reliable and effective.
The tuning options built into AMD's Radeon Software suite offer manual controls, along with automatic under-volting and automatic GPU and Memory overclocking. Finding the highest stable memory and GPU clocks, at the lowest voltage possible, while simultaneously increasing the max power target and keeping temperatures low, however, will yield the best overall overclocking results. If you'd rather not mess around though, you could simply enable Rage Mode, which essentially increases the power target and fan speeds, to increase the game / boost clocks, and eek out a bit of extra performance with a single-click.
Radeon RX 7900 XTX Manually Overclocked
At its stock settings, we saw the Radeon RX 7900 XTX's GPU clock typically hovering in the 2,700 - 2,800MHz range while gaming (give or take) with our particular sample. With a little tweaking we found that we could easily increase the memory clock on our card to 2,648MHz (21.1Gbps), and with a mild under-volt to 1.125mV, a max frequency set to 3,069MHz, and +15% to the power target, we typically saw a wider-range of real-world game clocks, commonly in the 2,900MHz - 3,080MHz range, though it occasionally spiked higher. The junction temperature while overclocked peaked in the low 80°C range with these settings, with a slight bump to the fan curve into the 2,000-ish RPM range.
With a 1.075mV voltage and 2,899MHz GPU clock, but similar tweaks to the memory speed (2,648MHz) and power target, we saw clocks on the XT hover around 100 - 200MHz lower than the XTX.
While we had the card overclocked, we saw some nice performance gains. The Radeon RX 7900 XTX increased its leads over the GeForce RTX 4080 in these tests and inched closer to the RTX 4090. And the Radeon RX 7900 XT was actually able to overtake the GeForce RTX 4080 while overclocked, which could make for some interesting partner boards, assuming some of them get aggressive with the VFC tweaks.
Total System Power Consumption Testing
We'd also like to cover a couple of final data points regarding power consumption and acoustics before we wrap up. Throughout all of our benchmarking and testing, we monitored noise output and tracked how much power the our test system was consuming using a power meter Our goal was to give you an idea as to how much power each GPU used while idle and also while under a heavy workload. These power numbers were captured during a FarCry 6 4K benchmark run with ray tracing enabled...
In terms of noise output, the new Radeon RX 7900 series is relatively tame when running at stock settings. The cards' fans typically peaked at about 1,700 - 1,800 RPM under long sustained loads, which produced only a dull whir that was hardly noticeable over our test system's PSU fans and CPU cooler. And at idle, they effectively inaudible. If you enable Rage mode for a quick boost to performance, however, the fan curve is much more aggressive and the cards will produce audibly more noise.
AMD Radeon RX 7900 Series Performance And Review Summary
The new AMD RDNA 3-based Radeon RX 7900 series is a massive upgrade over the previous generation, in terms of performance and efficiency. Save for a couple of anomalies that will likely get ironed out in future driver updates, the Radeon RX 7900 XT and Radeon RX 7900 XTX outperformed the Radeon RX 6900 XT by wide margins, and they did so quietly, while consuming similar or only marginally more power. Ray Tracing and traditional rendering show a big upticks in performance, as did compute and rendering workloads. Versus NVIDIA's offerings, the AMD Radeon RX 7900 falls right in-line with the company's disclosures. Generally speaking, the Radeon RX 7900 XT competes with, but generally trails the GeForce RTX 4080 by a couple of percentage points, whereas the higher-end Radeon RX 7900 XTX went toe-to-toe with the RTX 4080, often outperforming the 4080 in titles that don't implement tons of ray tracing. When ray tracing is employed, NVIDIA still has a clear advantage. And our limited latency tests showed NVIDIA with a lead in that regard as well.
So, what's the bottom line? The AMD Radeon RX 7900 series may not lead across the board, but these are some awesome graphics cards. The chiplet-based Navi 31 powering these cards is a powerful and capable GPU, paired to massive amounts of fast memory (20GB or 24GB), with a leading-edge feature set. These first Radeon RX 7900 series cards are also fairly tunable. We've only had the cards on hand for about a week, and even with a minimal amount of experimentation, some decent overclocks were possible, with the Radeon RX 7900 XTX exceeding 3GHz. We're eager to see what AMD's board partners do with the cards when more aggressively tuned custom boards arrive with additional PCIe power connectors to provide even more headroom.
In the end, the Radeon RX 7900 series keeps AMD in a competitive position in the high-end GPU space versus NVIDIA. The GeForce RTX 4090 still sits atop the hill, but the Radeon RX 7900 XT and Radeon RX 7900 XTX are right there alongside the RTX 4080. AMD's pricing, however, makes the Radeon RX 7900 series particularly interesting. In terms of MSRP at least, these new Radeons undercut NVIDIA by hundreds of dollars. AMD's new Radeon RX 7900 XT is priced at $899, while the Radeon RX 7900 XTX weighs in at $999 and NVIDIA's GeForce RTX 4080 (FE) sits at $1,199 commanding at least a $200 premium. Further, Radeon RX 7900 series pricing is also right in-line with the previous-gen, which all adds up to what could make for compelling upgrade options for many gamers.
