Graphics cards/Comparison
13 specifications
AMD Radeon RX 6600 XT vs AMD Radeon RX Vega 64
On paper, the AMD Radeon RX Vega 64 has more shading units, and the AMD Radeon RX Vega 64 has a wider memory bus. Specifications describe what each card is designed to do; how much of that either one holds under continuous load is a separate question.
AMD Radeon RX 6600 XT
AMD · Radeon RX 6000 · Desktop
AMD Radeon RX Vega 64
AMD · Radeon RX Vega · Desktop
Compute
Memory
Power and platform
A check marks the higher figure only on rows where higher is unambiguously better. Rows without one are not ties; they are specifications where “better” has no meaning.
Reading the table
What the difference means.
Video memory
Both carry 8 GB, so neither has the advantage where memory is the limit: high resolutions, heavy textures and local AI models fill both at the same point.
Memory bus
The RX Vega 64 moves data over a 2048-bit bus of HBM2; the RX 6600 XT uses 128-bit GDDR6. The bus width and the memory type together set how fast the chip can reach its own memory, which shows at high resolutions where every frame moves more data. A narrow bus with fast memory can match a wide one with slow memory, so neither figure settles it alone.
Shading units
The counts differ, 4,096 against 2,048, but these are different designs, and a shading unit on one is not the same amount of work as on the other. The row cannot be used to rank this pair.
Board power
The RX Vega 64 draws up to 295 W against 160 W. That is heat the case has to exhaust and current the power supply has to deliver: allow a supply of about 750 W for the RX Vega 64 with a typical processor, and check the card's power connectors against the supply's. A card that cannot shed its heat does not fail. It lowers its clocks after a few minutes, which is the frame rate that falls the longer you play.
Which to pick, on paper
- A small case or a modest power supply
- RX 6600 XT
- 160 W against 295 W: less heat, fewer power connectors, quieter fans.
What no table says
How much of its speed a graphics card keeps after the first minute depends on the cooling and the power limit of the machine it is in. If you own one of these, measure it: the test is free and runs in this browser.
Questions
- Is the RX 6600 XT better than the RX Vega 64?
- By need, on the specifications: a small case or a modest power supply: the RX 6600 XT. They are different designs, so the raw counts cannot rank them. Frame rates depend on the game and its settings, and how much speed either card keeps after ten minutes depends on its cooling, which is what a sustained test measures.
- What power supply does the RX Vega 64 need?
- Allow about 750 W with a typical processor, and make sure the supply has the power connectors the card uses. The RX 6600 XT at 160 W is easier on both.
More comparisons
- AMD Radeon RX 6600 XT vs AMD Radeon RX 6500 XT 8GB
- AMD Radeon RX 6600 XT vs NVIDIA GeForce RTX 5050
- AMD Radeon RX 6600 XT vs NVIDIA GeForce RTX 3060 8GB
- AMD Radeon RX 6600 XT vs AMD Radeon RX 6600
- AMD Radeon RX 6600 XT vs NVIDIA GeForce RTX 3060 Ti
- AMD Radeon RX Vega 64 vs AMD Radeon RX 6600
- AMD Radeon RX Vega 64 vs NVIDIA GeForce RTX 3060 8GB
- AMD Radeon RX Vega 64 vs AMD Radeon RX 6500 XT 8GB
- AMD Radeon RX Vega 64 vs NVIDIA GeForce RTX 2080
- AMD Radeon RX Vega 64 vs AMD Radeon RX 5700 XT
Every figure on this table is a design target. None of it is a measurement.
Nothing above describes how a graphics card behaves twenty minutes into a sustained workload, which is where two chips with nearly identical specifications routinely diverge. A boost clock is a ceiling the vendor permits, not a rate the chip sustains, and whether it holds depends on the cooling, the case, the power profile and the room. None of those appear on a specification sheet.
We deliberately do not reduce these figures to a single score. A composite invented from specifications would look authoritative and measure nothing, and choosing the weights would be choosing the winner.