What makes the Radeon RX 7900 series so much faster than its predecessor?
→ Increased Frequencies
The Radeon RX 7900 series are the first graphics cards to feature AMD's RDNA 3 GPU architecture that has been engineered for higher frequencies (designed to achieve 3GHz) while consuming less power than RDNA 2. According to AMD's estimate, it has improved frequencies by 15%, but performance per watt has gone up by a staggering 54%.
To go about achieving this, RDNA 3 enhanced the computation capabilities of the graphics core to double its peak operations output per cycle by doubling the number of F32 units, improved pipelining throughout, supporting new instruction to double the utilization rate (dual-issue SIMD32 or a single Wave 64 FMA instruction), and added dedicated matrix operations capability to boost machine learning effectiveness.
→ Optimised Cache
Efficiency of the entire graphics core has also been bolstered through upsizing of various caches (3MB L0 vector caches - 240% larger, 3MB L1 - 300% more, 6MB of L2 - 50% increase) and an updated AMD Infinity Cache to improve its bandwidth though the capacity has gone down from 128MB on RDNA 2 to 96MB on RX 7900 XTX and just 80MB on RX 7900 XT. AMD attributes this to a more balanced design that's suitable to the new RDNA 3 architecture.
→ Better Ray Tracing Improving ray tracing performance was an important agenda for RDNA 3 (which would be AMD's second generation of ray tracing as RDNA 2 was first to introduce RT) and AMD has stuck to using accelerators embedded in each of its compute units (CU) just like in RDNA 2.
Radeon RX 7900 series easily boasts many more CU units
According to AMD's estimate, it has improved frequencies by 15%,but performance per watt has gone up by a staggering 54%.
than its predecessors, and this directly allows the new GPUs to harbour 20% more ray tracing units. Secondly, the AMD engineers have been very judicious on how to use the rays by executing them efficiently and studying the process and outcome to dump unnecessary instruction to improve ray tracing logic, incorporate new box testing rules to exact more efficiency from each
Radeon RX 7900 series easily boasts many more CU units than its predecessors, and this directly allows the new GPUs to harbour 20% more ray tracing units.
ray (there's no upside to wasting precious cycles through inefficient rendering) and added hardware managed DirectX ray-tracing (DXR) flags. The result of all these improvements is that AMD says it has achieved up to 1.8x performance uplift on heavy raytraced workloads.
So all this sounds promising and RDNA 3 could be the real deal we've been expecting from AMD. Stay tuned for our in-depth reviews as the Radeon RX 7900 series is slated for retail availability by the time you read this. Exciting times indeed.