AMD Instinct MI300X vs AMD Radeon RX 7800 XT Comparison

Head-to-Head Benchmarks

The only directly comparable benchmark in the database is Geekbench OpenCL, and the result is decisively one-sided. The AMD Instinct MI300X scores 317,994, while the AMD Radeon RX 7800 XT scores 18,290. That represents a 1,638.6% advantage for the Instinct MI300X, a gap so large that it effectively places the two products in entirely different performance tiers.

The Instinct MI300X's score places it at the 100th percentile among all GPUs in the database. Its nearest rival, the NVIDIA H200 NVL, averages 334,891, which is 5% higher. The MI300X also outpaces the NVIDIA B200 (345,482, 8% higher) by a smaller margin than it trails the H200, and it beats the NVIDIA L40S (295,763) by 7.5% and the NVIDIA RTX 6000 Ada Generation (287,237) by 10.7%. In raw OpenCL compute, the MI300X is not merely competitive with the fastest accelerators in the database; it sits within a narrow band of top-tier results, trailing only the B200 and H200.

The RX 7800 XT, by contrast, sits at the 51st percentile among all GPUs. Its average benchmark score of 11,627 is within 0.5% of the NVIDIA GeForce GTX 1660 (11,680), 0.9% above the AMD Radeon Pro 5500M (11,528), and 1.3% above the NVIDIA Tesla K20c (11,479). The RX 7800 XT trails the AMD Radeon RX 6500 XT (11,842) by 1.8%. This is a mainstream desktop graphics card whose general-purpose compute performance is competitive with older and lower-tier parts, not with data center accelerators.

The 1638.6% delta in Geekbench OpenCL is not a marginal difference; it is an order-of-magnitude separation. The MI300X delivers roughly 17.4 times the OpenCL score of the RX 7800 XT. For context, the MI300X's score alone is 317,994, which exceeds the RX 7800 XT's entire suite of benchmark results combined, including its 3DMark Steel Nomad DX12 score of 4,157, its Vulkan score of 54,228, and its Passmark G3D score of 24,176.

The Verdict

The data indicates that the AMD Instinct MI300X and AMD Radeon RX 7800 XT are not competitors in any meaningful sense. They share a manufacturer and a 5 nm TSMC process node, but their design goals, performance envelopes, and target workloads diverge completely.

The Instinct MI300X is a data center accelerator with no display outputs. It is designed for compute-heavy workloads such as large-scale AI training and inference, scientific simulation, and high-performance computing. Its Geekbench OpenCL score of 317,994 places it in the top percentile of all GPUs in the database, and its nearest rivals are all NVIDIA data center parts: the H200 NVL, B200, L40S, and RTX 6000 Ada Generation. Any system builder or researcher looking for maximum raw compute throughput, as measured by OpenCL, should look at the MI300X alongside those NVIDIA accelerators.

The RX 7800 XT is a desktop gaming and workstation card. It has display outputs (1x HDMI 2.1a, 3x DisplayPort 2.1), supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, and its benchmark profile includes gaming-oriented tests like 3DMark Steel Nomad DX12 (4,157), Passmark DirectX 11 (249), and Passmark DirectX 9 (304). Its OpenCL score of 18,290 is far below the MI300X, but that is irrelevant for its intended use case. The RX 7800 XT's nearest rivals are mainstream and mid-range GPUs like the GTX 1660 and RX 6500 XT, not data center accelerators.

The choice between these two products is dictated by the workload. For compute tasks that stress OpenCL performance, the MI300X is the obvious selection, as it outperforms the RX 7800 XT by 1,638.6% in the only shared benchmark. For rendering graphics to a display, the RX 7800 XT is the only viable option of the two, as the MI300X has no display outputs and no graphics API support. The MI300X also has a 750 W TDP and no power connectors, requiring an OAM module and a suggested PSU of 1150 W, whereas the RX 7800 XT is a dual-slot card with 2x 8-pin connectors and a 263 W TDP, suited for standard desktop power supplies.

Architecture Differences

The two GPUs are built on the same 5 nm TSMC process node and use the same number "3.0" in their architecture names, but the underlying designs are fundamentally different.

The Instinct MI300X uses CDNA 3.0 architecture, with the chip codename Aqua Vanjaram. It is a compute-focused design with no traditional rasterization hardware: its pixel rate is 0 MPixel/s and its ROP count is 0. The MI300X has 19,456 shading units and 1,216 texture mapping units, delivering a texture rate of 2,553.6 GTexel/s and 81.72 TFLOPS of FP32 and FP16 compute (1:1 ratio). This is a massive parallel compute engine.

The RX 7800 XT uses RDNA 3.0 architecture, with the chip codename Navi 32 (also referred to as Wheat Nas). It is a graphics-first design with 3,840 shading units, 240 TMUs, and 96 ROPs. It has 60 ray tracing cores, a feature the MI300X lacks entirely. Its pixel rate is 233.3 GPixel/s, its texture rate is 583.2 GTexel/s, and its FP32 and FP16 compute are both 37.32 TFLOPS (1:1). The RX 7800 XT supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI300X reports N/A for all graphics APIs.

The transistor counts reflect the different design philosophies. The MI300X packs 153,000 million transistors on a 1017 mm² die, for a density of 150.4M transistors per mm². The RX 7800 XT has 28,100 million transistors on a 346 mm² die, for a density of 81.2M per mm². The MI300X has more than five times the transistor count and nearly three times the die area, but its transistor density is roughly 85% higher, indicating a much more densely packed compute design.

Clock speeds also differ. The MI300X runs at a base clock of 1000 MHz and a boost clock of 2100 MHz. The RX 7800 XT has a higher base clock of 1295 MHz, a higher boost clock of 2430 MHz, and a game clock of 2124 MHz. Despite lower clocks, the MI300X's massive shading unit count and memory subsystem deliver far higher raw throughput.

Specification Differences

The most striking difference is memory. The MI300X has 192 GB of HBM3 on an 8192-bit bus, with a bandwidth of 5.32 TB/s. The RX 7800 XT has 16 GB of GDDR6 on a 256-bit bus, with a bandwidth of 624.1 GB/s. That is a 12x difference in capacity and an 8.5x difference in bandwidth. The MI300X's memory clock is 1300 MHz (5.2 Gbps effective), while the RX 7800 XT's memory clock is 2438 MHz (19.5 Gbps effective), but the MI300X's vastly wider bus more than compensates.

The MI300X has 19,456 shading units versus 3,840 on the RX 7800 XT, and 1,216 TMUs versus 240. The RX 7800 XT has 96 ROPs and 60 ray tracing cores; the MI300X has 0 ROPs and no ray tracing cores. The MI300X outputs 81.72 TFLOPS of FP32 and FP16, while the RX 7800 XT outputs 37.32 TFLOPS of each. The MI300X's texture rate of 2,553.6 GTexel/s is more than four times the RX 7800 XT's 583.2 GTexel/s.

The power and physical specifications diverge sharply. The MI300X has a 750 W TDP, requires no power connectors (it is an OAM module), and needs a suggested PSU of 1150 W. The RX 7800 XT has a 263 W TDP, uses 2x 8-pin power connectors, and requires a 600 W suggested PSU. The MI300X is an OAM module with no specified dimensions, while the RX 7800 XT is a dual-slot card measuring 267 mm (10.5 inches) in length, 111 mm (4.4 inches) in height, and 50 mm (2 inches) in width.

The bus interface differs: the MI300X uses PCIe 5.0 x16, while the RX 7800 XT uses PCIe 4.0 x16. The MI300X has no display outputs; the RX 7800 XT has 1x HDMI 2.1a and 3x DisplayPort 2.1. The MI300X's production status is not listed, while the RX 7800 XT is listed as Active. The MI300X's predecessor is the Radeon Instinct, while the RX 7800 XT's predecessor is Navi II and its successor is Navi IV. Release dates are close: the RX 7800 XT launched on 2023-09-05, and the MI300X launched on 2023-12-05.

The RX 7800 XT has a launch MSRP of 499 USD. The MI300X has no listed launch MSRP.

FAQ

Q: Which GPU has a higher Geekbench OpenCL score?

A: The AMD Instinct MI300X scores 317,994, while the AMD Radeon RX 7800 XT scores 18,290. The MI300X leads by 1,638.6%.

Q: Which GPU has more memory and bandwidth?

A: The MI300X has 192 GB of HBM3 with a bandwidth of 5.32 TB/s on an 8192-bit bus. The RX 7800 XT has 16 GB of GDDR6 with a bandwidth of 624.1 GB/s on a 256-bit bus.

Q: Can the AMD Instinct MI300X output video to a display?

A: No. The MI300X has no display outputs and reports N/A for DirectX, OpenGL, and Vulkan support. The RX 7800 XT has 1x HDMI 2.1a and 3x DisplayPort 2.1 outputs and supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4.

Q: What are the nearest rivals for each GPU in the database?

A: The MI300X's nearest rivals are the NVIDIA H200 NVL (334,891 average score, 5% higher), NVIDIA B200 (345,482, 8% higher), NVIDIA L40S (295,763, 7.5% lower), and NVIDIA RTX 6000 Ada Generation (287,237, 10.7% lower). The RX 7800 XT's nearest rivals are the NVIDIA GeForce GTX 1660 (11,680, 0.5% higher), AMD Radeon Pro 5500M (11,528, 0.9% lower), NVIDIA Tesla K20c (11,479, 1.3% lower), and AMD Radeon RX 6500 XT (11,842, 1.8% higher).

Q: Which GPU has more shading units and TMUs?

A: The MI300X has 19,456 shading units and 1,216 TMUs. The RX 7800 XT has 3,840 shading units and 240 TMUs.

Q: What is the TDP and power requirement for each GPU?

A: The MI300X has a 750 W TDP, uses no power connectors (OAM module), and requires a suggested PSU of 1150 W. The RX 7800 XT has a 263 W TDP, uses 2x 8-pin connectors, and requires a suggested PSU of 600 W.