AMD’s Radeon RX 7900 XTX is far from perfect, but it offers solid gaming performance at its $999 price point. Its ray-tracing capabilities are fairly dull, and power efficiency is lower than promised, which translates to poor thermals. Data compiled by HardwareLuxx shows that almost all models of the RX 7900 XTX run pretty toasty, some even hitting over 100C under load:
The reference model, in particular, runs hotter than it should. We’re looking at hotspot temperatures of up to 110C with an average of 92C. That’s a few degrees over the safety margin and a cause for concern. This can not only lead to clock throttling (resulting in a performance drop) but can also adversely affect the life cycle of the GPU. In our review of the Radeon RX 7900 XT, we saw the RDNA 3 part hit 80C in most 4K gaming workloads.
Usually, you’d chalk this down to excessive power consumption or an inefficient design, but in this case, the chiplet architecture is the culprit. The GCD and MCDs are two completely different kinds of dies. One is a compute powerhouse with dense 5nm transistors, while the other primarily consists of SRAM. The two will have varying heights (distance to heatsink), which is known to adversely affect heat dissipation in Ryzen processors.
Designing special blocks that take into account the minuscule difference in the height of the two chiplets is too much work. Board partners are likelier to use brute force cooling over excessive R&D investments.