The Radeon RX 9070 XT GPUs have been the center of attention lately, and a recent report has stirred some controversy regarding the performance differences between models equipped with Samsung GDDR6 memory and those with SK Hynix memory. 
A Chinese tech reviewer, known as ‘51972,’ conducted a series of tests and found a notable performance drop in the RX 9070 XT units featuring Samsung GDDR6 modules compared to their SK Hynix counterparts.
In a detailed video published on Bilibili, 51972 explained that after testing over 20 units of the RX 9070 XT, it became apparent that those using Samsung GDDR6 memory lagged behind by 1-2% in 3DMark Speedway tests, despite having higher clock speeds and power consumption
. Even the premium OC models with Samsung memory were slower than the base editions with SK Hynix modules.
Both Samsung and SK Hynix supply AMD with memory for their GPUs, making it common to see some RX 9070 XTs equipped with Samsung modules and others with SK Hynix. However, the performance discrepancy noticed by 51972 was subtle yet consistent, requiring a careful segregation of Samsung and SK Hynix-based models to reveal the difference. 
The root cause appears to be the Samsung GDDR6 memory’s “loose” timings, which increase memory latency, as confirmed by AMD’s FAE team in China. While SK Hynix-based RX 9070 XTs showed around 350-360ns of latency, the Samsung-based cards had slightly higher latency, reaching up to 370-380ns.
This finding has stirred a mix of reactions in the community, with some users pointing out that Samsung memory, despite this performance gap, has historically been associated with lower-cost solutions. Others have speculated that the issue might be addressed with firmware updates, although the performance difference is relatively minor for most users. Despite the controversy, it’s clear that AMD’s dual-sourcing strategy-using both Samsung and SK Hynix memory-is unlikely to be changed anytime soon.