AMD Instinct MI325X vs AMD Radeon RX 7800 XT Comparison

Head-to-Head Benchmarks

The AMD Instinct MI325X and the AMD Radeon RX 7800 XT occupy entirely different segments of the accelerator market, and the recorded data confirms this divide. The MI325X is built on the CDNA 3.0 architecture with the Aqua Vanjaram chip, while the RX 7800 XT uses the RDNA 3.0 architecture with the Navi 32 chip. Both are manufactured on a 5 nm process at TSMC, but the similarities end there.

Looking at raw compute throughput, the MI325X delivers 81.72 TFLOPS of FP32 performance, which is 44.4 TFLOPS higher than the RX 7800 XT's 37.32 TFLOPS. This represents a 119% advantage in single-precision floating-point work. The FP16 numbers are identical to the FP32 figures for both cards, with the MI325X again posting 81.72 TFLOPS versus 37.32 TFLOPS on the RX 7800 XT, indicating a 1:1 ratio for both architectures.

The memory subsystem shows an even larger gap. The MI325X carries 256 GB of HBM3e memory on an 8192-bit bus, producing 6.14 TB/s of bandwidth. The RX 7800 XT has 16 GB of GDDR6 on a 256-bit bus, yielding 624.1 GB/s. The MI325X provides nearly ten times the bandwidth, a decisive factor for data-center workloads that stream large datasets through the memory hierarchy.

Texture processing also favors the MI325X. It achieves 2,553.6 GTexel/s across 1,216 texture mapping units, while the RX 7800 XT reaches 583.2 GTexel/s with 240 TMUs. The MI325X is 4.4 times faster in texturing throughput. Pixel rate tells a different story: the MI325X reports 0 MPixel/s with no ROPs, whereas the RX 7800 XT processes 233.3 GPixel/s through 96 raster operation units. This reflects the MI325X's compute-focused design, which omits the graphics rasterization pipeline entirely.

In benchmark results, only the RX 7800 XT has recorded scores in the database. Its average benchmark score is 11,627, placing it in the 51st percentile of all GPUs. The MI325X has no recorded benchmarks and sits at the 50th percentile with an average score of 0. The nearest rivals for the RX 7800 XT show a tight cluster: the NVIDIA GeForce GTX 1660 scores 11,680, which is 0.5% higher, the AMD Radeon Pro 5500M scores 11,528, which is 0.9% lower, the NVIDIA Tesla K20c scores 11,479, which is 1.3% lower, and the AMD Radeon RX 6500 XT scores 11,842, which is 1.8% higher. The RX 7800 XT sits in the middle of this group, slightly ahead of the Radeon Pro 5500M and Tesla K20c but slightly behind the GTX 1660 and RX 6500 XT.

Where Each One Wins

The RX 7800 XT wins in every graphics-oriented comparison available in the data. It has a complete display output suite with 1x HDMI 2.1a and 3x DisplayPort 2.1, while the MI325X has no display outputs. The RX 7800 XT supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4; the MI325X reports N/A for all three graphics APIs. The RX 7800 XT also has 60 ray tracing cores, a feature absent from the MI325X's specifications.

In rasterization, the RX 7800 XT delivers 233.3 GPixel/s, a capability the MI325X does not implement. The RX 7800 XT's 96 ROPs handle final pixel output, while the MI325X has zero ROPs. Its 16 GB of GDDR6 memory is ample for high-resolution gaming textures, and its 624.1 GB/s bandwidth supports 1440p and 4K workloads in the context of its benchmark class. The recorded PassMark scores confirm its graphics strengths: 24,176 in G3D, 304 in DirectX 9, 249 in DirectX 11, 121 in DirectX 10, and 93 in DirectX 12. The Geekbench Vulkan score of 54,228 and OpenCL score of 18,290 round out its measured performance profile.

The MI325X wins in compute-scale metrics. Its 19,456 shading units dwarf the RX 7800 XT's 3,840. The 1,216 TMUs versus 240 represent a 5.1 times advantage. The 256 GB memory capacity is 16 times larger than the RX 7800 XT's 16 GB. The 6.14 TB/s memory bandwidth is roughly 9.8 times higher. The transistor count tells the scale story: 153,000 million transistors on a 1,017 mm² die, compared to 28,100 million on a 346 mm² die. The MI325X's transistor density is 150.4M per mm² versus 81.2M per mm² for the RX 7800 XT.

The MI325X also carries a PCIe 5.0 x16 interface, one generation newer than the RX 7800 XT's PCIe 4.0 x16. Its boost clock of 2100 MHz is lower than the RX 7800 XT's 2430 MHz boost, but the massive shader count compensates in parallel compute workloads. The FP32 output of 81.72 TFLOPS positions it for server and scientific computing tasks, where the RX 7800 XT's 37.32 TFLOPS would be insufficient for large-scale matrix operations.

The Verdict

The data indicates two purpose-built accelerators with minimal overlap. The AMD Instinct MI325X is designed for compute-intensive environments. Its 256 GB HBM3e memory, 6.14 TB/s bandwidth, and 81.72 TFLOPS FP32 throughput serve workloads that require massive memory capacity and sustained numeric throughput. It has no display outputs, no graphics API support, and no rasterization hardware, confirming it is not intended for interactive graphics. Its 1000 W TDP and OAM Module slot width target server racks rather than desktop chassis. It requires a 1400 W suggested PSU and uses no power connectors because it draws power through the OAM interface.

The AMD Radeon RX 7800 XT is a conventional graphics card. Its 263 W TDP, dual-slot form factor, and 2x 8-pin power connectors fit standard desktop builds. It has a 267 mm length, 111 mm height, and 50 mm width, and its 600 W suggested PSU is typical for its class. The 16 GB GDDR6 memory, 96 ROPs, 60 ray tracing cores, and full display output suite make it suitable for gaming and workstation graphics. Its 51st percentile ranking and average benchmark score of 11,627 place it in the mid-range of the database's GPU population. Its nearest rivals all score within 1.8% of its average, indicating a competitive segment.

The MI325X has no benchmark entries, so the database contains no direct performance measurements for it. Its percentile of 50 with an average score of 0 reflects this absence of data. The analysis of its capabilities must rely on architectural specifications alone. The RX 7800 XT, by contrast, has ten recorded benchmark scores spanning DirectX versions, OpenCL, Vulkan, and general compute tests.

The production status also differs. The RX 7800 XT is listed as Active, while the MI325X has no production status recorded. The RX 7800 XT succeeded the Navi II generation and was succeeded by Navi IV. The MI325X lists Radeon Instinct as its predecessor. The RX 7800 XT released on 2023-09-05, and the MI325X released on 2024-10-09, roughly 13 months later.

FAQ

Q: Which card has more memory bandwidth?

A: The AMD Instinct MI325X has 6.14 TB/s of bandwidth from its 8192-bit HBM3e interface, compared to 624.1 GB/s on the RX 7800 XT's 256-bit GDDR6 interface.

Q: Does the MI325X support DirectX?

A: No. The MI325X reports N/A for DirectX, OpenGL, and Vulkan support. It also has no display outputs.

Q: What is the average benchmark score of the RX 7800 XT?

A: The RX 7800 XT has an average benchmark score of 11,627 across ten recorded tests, placing it in the 51st percentile of all GPUs in the database.

Q: How does the RX 7800 XT compare to its nearest rival, the GTX 1660?

A: The GTX 1660 scores 11,680, which is 0.5% higher than the RX 7800 XT's average. The RX 7800 XT trails by a narrow margin in this comparison.

Q: What is the FP32 performance of each card?

A: The MI325X delivers 81.72 TFLOPS of FP32 performance, while the RX 7800 XT delivers 37.32 TFLOPS. Both cards report identical FP16 performance at a 1:1 ratio.

Q: What power supply is suggested for each card?

A: The MI325X requires a 1400 W suggested PSU, while the RX 7800 XT requires a 600 W suggested PSU.

Architecture Differences

The two accelerators use different architectures from AMD. The MI325X uses CDNA 3.0, designed for compute acceleration, while the RX 7800 XT uses RDNA 3.0, designed for graphics rendering. The chip codenames reflect this split: Aqua Vanjaram for the MI325X and Navi 32 for the RX 7800 XT.

The MI325X has 19,456 shading units, 1,216 TMUs, and zero ROPs. It has no ray tracing cores listed and no tensor cores listed. Its texture rate is 2,553.6 GTexel/s, and its pixel rate is 0 MPixel/s. The RX 7800 XT has 3,840 shading units, 240 TMUs, 96 ROPs, and 60 ray tracing cores. Its texture rate is 583.2 GTexel/s, and its pixel rate is 233.3 GPixel/s.

Memory architecture differs fundamentally. The MI325X uses HBM3e with 256 GB capacity and an 8192-bit bus. The RX 7800 XT uses GDDR6 with 16 GB capacity and a 256-bit bus. The MI325X memory clock is 1500 MHz with 6 Gbps effective, while the RX 7800 XT memory clock is 2438 MHz with 19.5 Gbps effective. Despite the higher effective clock on the RX 7800 XT, the MI325X's wider bus produces far greater total bandwidth.

The MI325X is manufactured on a 1017 mm² die with 153,000 million transistors, yielding a density of 150.4M per mm². The RX 7800 XT uses a 346 mm² die with 28,100 million transistors, yielding 81.2M per mm². The MI325X die is nearly three times larger and packs over five times the transistors.

Clock behavior also differs. The MI325X has a 1000 MHz base clock and 2100 MHz boost clock. The RX 7800 XT has a 1295 MHz base clock, 2124 MHz game clock, and 2430 MHz boost clock. The RX 7800 XT runs at higher frequencies, but the MI325X compensates with its larger execution resource count.

Power and physical specifications diverge sharply. The MI325X has a 1000 W TDP, uses an OAM Module slot width, has no power connectors, and requires a 1400 W suggested PSU. The RX 7800 XT has a 263 W TDP, uses a dual-slot form factor, has 2x 8-pin power connectors, and requires a 600 W suggested PSU. The MI325X measures no dimensions in the database, while the RX 7800 XT measures 267 mm by 111 mm by 50 mm.

Bus interfaces differ by one generation. The MI325X uses PCIe 5.0 x16, and the RX 7800 XT uses PCIe 4.0 x16. The RX 7800 XT lists a launch MSRP of 499 USD. The MI325X has no launch MSRP recorded. The RX 7800 XT provides display outputs with 1x HDMI 2.1a and 3x DisplayPort 2.1, while the MI325X provides no outputs. The RX 7800 XT supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI325X supports none of these APIs.

The MI325X belongs to the Instinct (MIx) generation and lists Radeon Instinct as its predecessor. The RX 7800 XT belongs to the Radeon RX 7000 series and the Navi III (RX 7000) generation, with Navi II as predecessor and Navi IV as successor. The RX 7800 XT is in Active production, while the MI325X has no production status recorded.