Radeon RX 7800 XT vs GeForce GTX 645 OEM
Primary details
GPU architecture, market segment, value for money and other general parameters compared.
| Place in the ranking | not rated | 30 |
| Place by popularity | not in top-100 | 40 |
| Cost-effectiveness evaluation | no data | 68.04 |
| Power efficiency | no data | 16.46 |
| Architecture | Kepler (2012−2018) | RDNA 3.0 (2022−2024) |
| GPU code name | GK106 | Navi 32 |
| Market segment | Desktop | Desktop |
| Release date | 22 April 2013 (11 years ago) | 25 August 2023 (1 year ago) |
| Launch price (MSRP) | no data | $499 |
Cost-effectiveness evaluation
Performance to price ratio. The higher, the better.
Detailed specifications
General parameters such as number of shaders, GPU core base clock and boost clock speeds, manufacturing process, texturing and calculation speed. Note that power consumption of some graphics cards can well exceed their nominal TDP, especially when overclocked.
| Pipelines / CUDA cores | 576 | 3840 |
| Core clock speed | 824 MHz | 1295 MHz |
| Boost clock speed | no data | 2430 MHz |
| Number of transistors | 2,540 million | 28,100 million |
| Manufacturing process technology | 28 nm | 5 nm |
| Power consumption (TDP) | 65 Watt | 263 Watt |
| Texture fill rate | 39.55 | 583.2 |
| Floating-point processing power | 0.9492 TFLOPS | 37.32 TFLOPS |
| ROPs | 16 | 96 |
| TMUs | 48 | 240 |
| Ray Tracing Cores | no data | 60 |
Form factor & compatibility
Information on compatibility with other computer components. Useful when choosing a future computer configuration or upgrading an existing one. For desktop graphics cards it's interface and bus (motherboard compatibility), additional power connectors (power supply compatibility).
| Interface | PCIe 3.0 x16 | PCIe 4.0 x16 |
| Length | 147 mm | 267 mm |
| Width | 1-slot | 2-slot |
| Supplementary power connectors | None | 2x 8-pin |
VRAM capacity and type
Parameters of VRAM installed: its type, size, bus, clock and resulting bandwidth. Integrated GPUs have no dedicated video RAM and use a shared part of system RAM.
| Memory type | GDDR5 | GDDR6 |
| Maximum RAM amount | 1 GB | 16 GB |
| Memory bus width | 128 Bit | 256 Bit |
| Memory clock speed | 1000 MHz | 2438 MHz |
| Memory bandwidth | 64 GB/s | 624.1 GB/s |
| Shared memory | - | - |
Connectivity and outputs
Types and number of video connectors present on the reviewed GPUs. As a rule, data in this section is precise only for desktop reference ones (so-called Founders Edition for NVIDIA chips). OEM manufacturers may change the number and type of output ports, while for notebook cards availability of certain video outputs ports depends on the laptop model rather than on the card itself.
| Display Connectors | 1x DVI, 1x HDMI, 1x DisplayPort | 1x HDMI 2.1a, 3x DisplayPort 2.1 |
| HDMI | + | + |
API compatibility
List of supported 3D and general-purpose computing APIs, including their specific versions.
| DirectX | 12 (11_0) | 12 Ultimate (12_2) |
| Shader Model | 5.1 | 6.7 |
| OpenGL | 4.6 | 4.6 |
| OpenCL | 1.2 | 2.2 |
| Vulkan | 1.1.126 | 1.3 |
| CUDA | 3.0 | - |
Pros & cons summary
| Recency | 22 April 2013 | 25 August 2023 |
| Maximum RAM amount | 1 GB | 16 GB |
| Chip lithography | 28 nm | 5 nm |
| Power consumption (TDP) | 65 Watt | 263 Watt |
GTX 645 OEM has 304.6% lower power consumption.
RX 7800 XT, on the other hand, has an age advantage of 10 years, a 1500% higher maximum VRAM amount, and a 460% more advanced lithography process.
We couldn't decide between GeForce GTX 645 OEM and Radeon RX 7800 XT. We've got no test results to judge.
Should you still have questions concerning choice between the reviewed GPUs, ask them in Comments section, and we shall answer.
Comparisons with similar GPUs
We selected several comparisons of graphics cards with performance close to those reviewed, providing you with more options to consider.
