Given RX 9060 XT 8GB’s PCIe 5.0 interface comes with all 16 lanes enabled, many hoped this would soften the bandwidth blow on older platforms with earlier expansion slots. However, it seems pairing the memory-constrained graphics card with aged motherboards can lead to decreases in performance greater than 50%.
YouTube channel Hardware Unboxed showcased this issue in its exploration of RX 9060 XT 8GB performance scaling across PCIe 5.0, 4.0, and 3.0. Given its lowly VRAM capacity, the graphics card must fetch additional data from system RAM through the PCIe slot when its buffer is at capacity. The impact of this fallback has become increasingly more noticeable in modern games, and is particularly problematic for a pixel pusher that many budget gamers will undoubtedly pair with older, slower connections.
It isn’t difficult to saturate 8GB of VRAM, as the selection of games curated by Hardware Unboxed demonstrates. For example, using the ‘Very Ultra’ preset in Indiana Jones and the Great Circle at 1440p requires close to 12GB of memory as RX 9060 XT 16GB comparative data shows. Falling back to system memory sees the 8GB variant’s average frame rate fall behind its sibling by an enormous 32%, despite having the advantage of a PCIe 5.0 x16 interface.
However, things go from bad to worse when the card with older interfaces. Running in a PCIe 4.0 x16 expansion slot pushes average frame rates on RX 9060 XT 8GB, from 92fps to 65fps, a decline of 29%. Going even further back in time to PCIe 3.0 x16 is painful, as performance tanks from 92fps to 46fps, a staggering 50% drop. Of course, this percentages become even more egregious if you compare them to RX 9060 XT 16GB.
Indiana Jones wasn’t the only example of this massive performance decline. Using RX 9060 XT 8GB to run F1 25’s ‘Very High’ preset at 1440p saw similar issues arise. Once again, average frame rates are noticeably lower than RX 9060 XT 16GB despite each SKU using the same PCIe 5.0 x16 interface, falling by 18%. Proceeding to PCIe 4.0 x16 results in a 31% fall, from 59fps to 41fps, culminating in an enormous 42% reduction at PCIe 3.0 x16.
Other instances include Marvel’s Spider-Man 2, which saw a 19% regression using PCIe 4.0 rising to 42% at PCIe 3.0. The same goes for Ratchet and Clank, where the card’s performance dropped by 26% using PCIe 4.0 and 42% using PCIe 3.0.
It remains a shame that the Navi 44 GPU at the heart of RX 9060 XT 8GB fall this way. As RX 9060 XT 16GB shows, with enough VRAM, any concerns about PCIe bandwidth disappear. Looking forward, this issue will only become more prevalent as games occupy more of the buffer, at which point lowering resolution or settings becomes the only option.
As we said in our RX 9060 XT 16GB review, it’s well worth spending that extra $50 and skipping the RX 9060 XT 8GB as well as RTX 5060. If you can’t push your budget beyond $300, though, give Arc B580 a look with its 12GB of VRAM.
