AMD Radeon RX 7900 XT and 7900 XTX review: can RDNA 3 bring the value?

The story so far with the next generation of PC graphics cards is fairly straightforward: it kicked off with the launch of the RTX 4090, which delivered flagship performance across the board, backed by a vision from Nvidia of a whole new era for PC gaming with ray tracing at the forefront. The story turned sour with RTX 4080 – a fine GPU with an excessively poor price-point. AMD is striking back right now with its RDNA 3-powered RX 7900 XTX and 7900 XT at a point where Nvidia’s 4080 misstep offers the Radeon team the biggest opportunity in years to strike back. The excitement is palpable, the prospect of competition against a dominant market leader is mouthwatering – but while the RX 7900 XTX in particular can impress, there isn’t quite the killer blow here many would have hoped for – and there’s palpable disappointment with RX 7900 XT.

Going into this generation, AMD offered up performance figures suggesting a 1.5x to 1.7x performance multiplier for the RX 7900 XTX when compared against the outgoing RX 6950 XT, its current flagship. Those performance increases can be achieved, but the boost to frame-rates is not uniform across the board – going into this review period, the hype suggested that the XTX should be knocking on the door of RTX 4090 performance in rasterisation, while soundly thrashing the RTX 4080. This happen, but not with the kind of frequency that establishes this as the norm. Meanwhile, the RX 7900 XT is simply too cut back compared to its flagship counterpart to justify its price – it’s a major misstep from AMD.

Of course, that’s looking at the new RDNA 3 cards simply in terms of their performance. At the engineering level – and from a strategic perspective – the new offerings, based on the Navi 31 processor, are innovative and impressive. Moving on from the concept of a monolithic processor surrounded by memory modules, AMD has taken the chiplet approach that worked so well with Ryzen and adapted it for graphics. The GCD is a 5nm TSMC-produced chiplet that sits at the heart of the new cards providing the raw graphics power, surrounded by MCDs on the cheaper 6nm node which house the Infinity Cache – 80MB on the RX 7900 XT, 96MB on the 7900 XTX. Smaller chips are more cost-efficient and potentially more scalable. While there’s only one GCD with Navi 31, the endgame is obvious: scale up performance by interfacing more GCDs together in the same way that AMD scales up CPU performance in Ryzen.

Beyond that, the RDNA 3 cards offer up a few more advantages: the Radiance Display engine is state-of-the-art, with DisplayPort 2.1 connections opening the door to support for next-gen displays running at a maximum 1440p at 900Hz (!), 4K at 480Hz and 8K at 165Hz. This presents a nice advantage over Nvidia’s latest, still running with DisplayPort 1.4, limited to 8K at 60Hz and 4K at 240Hz. With that said, I think the results we’ll see suggest that the applications of those ultra-high refresh rates are limited compared to the power of the cards (and indeed the limits of current CPUs). That said, esports favourites should fare well.

One thing I’d like to point out before we continue is that the stated ‘game clocks’ in AMD’s official specifications – as seen above – are very, very understated compared to actual performance, which is highly dynamic. Riva Tuner Statistics Server reported frequencies more in the 2.6GHz to 2.8GHz range in my tests, and at 1080p I even saw the 7900 XTX flirt with 2.9GHz. In terms of the frequency war against Nvidia, RDNA 3 seems to be broadly comparable with the Ada Lovelace cards. I mention this as sub-par clocks were one of the primary surprises/disappointments from the RDNA 3 reveal – the reality is just fine.