Ryzen 9 6900HX: Currently the strongest iGPU but memory bandwidth is still the bottleneck
3 min readRyzen 9 6900HX: Currently the strongest iGPU but memory bandwidth is still the bottleneck
Ryzen 9 6900HX core display test: Currently the strongest iGPU but memory bandwidth is still the bottleneck.
In fact, when AMD released the Radeon RX 6400 graphics card in April, the first thing I thought of when I saw the specifications of the graphics card was not the RX 6500 XT, which is the same source as it, but the Rembrandt architecture Ryzen 6000 series they released in January.
Mobile processor , look at the RDNA 2 architecture used by the RX 6400. The Radeon 680M of the Ryzen 6000 is also an RDNA 2 architecture.
The RX 6400 has 12 sets of CUs, and the 680M also has 12 sets of CUs. The RX 6400 uses TSMC’s 6nm process, and Rembrandt uses it.
It is also TSMC’s 6nm process. Although it is not exactly the same, the similarity is very high.
When the RX 6400 was first released, we didn’t have a notebook with a Ryzen 6000 series processor on hand, so unfortunately we didn’t do a comparison test between the Radeon RX 6400 and the Radeon 680M.
Recently, the ROG Ice Blade 6 dual-screen gaming notebook we tested uses the Ryzen 9 6900HX processor, which can be switched to the core display mode, and the power of the core display can run to more than 50W, which is just used for this comparison test.
Specification parameter comparison
| model | Ryzen 9 6900HX Radeon 680M | Radeon RX 6400 | Ryzen 7 5700G Radeon Graphics |
|---|---|---|---|
| Architecture | RDNA 2 | RDNA 2 | Vega |
| computing unit | 12 | 12 | 8 |
| GPU frequency | 2400 MHz | 2039~2321 MHz | 2000 MHz |
| light accelerator | 12 | 12 | N/A |
| texture unit | 48 | 48 | 32 |
| grating unit | 32 | 32 | 8 |
| stream processor | 768 | 768 | 512 |
| Video memory/memory type | DDR5 LPDDR5 | GDDR6 | DDR3 |
| Video memory interface | 128-bit | 64-bit | 128-bit |
| Effective memory speed | (DDR5)4.8 Gbps (LPDDR5)6.4 Gbps | 16 Gbps | 3.2 Gbps |
| Maximum memory bandwidth | (DDR5)76.8 GB/s (LPDDR5)102.4 GB/s | 128 GB / s | 51.2 GB / s |
| H264/AVC decoding | Yes | Yes | Yes |
| H264/AVC encoding | Yes | no | Yes |
| H265/HEVC decoding | Yes | Yes | Yes |
| H265/HEVC encoding | Yes | no | Yes |
| AV1 decoding | Yes | no | no |
If you carefully compare the Radeon 680M core graphics and Radeon RX 6400 independent graphics specifications, you will find that the GPU frequency of the Radeon 680M is even higher, and can run to 2400MHz, while the maximum frequency of the RX 6400 is only 2321MHz.
Of course, the RX 6400 is an independent graphics card. It has its own video memory.
Although there is only 64bit/4GB GDDR6, the memory bandwidth is higher than that of the Radeon 680M as a nuclear display.
The memory bandwidth of the Ryzen 7 5700G in the above table is calculated according to the official DDR4-3200, but it is a retail desktop CPU.
The frequency of the memory is basically determined by the user. If you use 3600MHz memory, the memory bandwidth should be 57.6Gbps.
In terms of multimedia engines, the RX 6400 is really weaker than the Ryzen 7 5700G with Vega core display. It has no video encoding function at all, nor does it support AV1 video decoding.
Although Vega core display does not support AV1 format decoding, but It supports at least H.264 and H.265 encoding functions. As for the Radeon 680M core display, it basically completely inherits the VCN 3.0 video engine of the RX 6000 series, and the encoding and decoding functions are relatively complete.
Testbed and Instructions
| Hardwares | Testing Platform |
| CPU | Ryzen 7 5700G |
| motherboard | MSI MPG X570S CARBON MAX WIFI Motherboard |
| graphics card | Radeon RX 6400 |
| Memory | XPG Longyao D50 DDR4-3600 memory 16GB*2 |
| hard disk | Team Group Leader EXPERT PCIe 2TB SSD |
| heat sink | Yajun G3 air cooling radiator |
| power supply | ROG Thor Power Supply 1200W |
| Software configuration | |
| operating system | Microsoft Windows 11 64bit build 21H2 |
ROG Ice Blade 6 Dual Screen
| CPU | AMD Ryzen 9 6900HX |
| GPU | Independent graphics: NVIDIA GeForce RTX 3080 Ti Laptop GPU (7424 CUDA, up to 1445MHz boost frequency, 16GB 256-bit GDDR6 memory, up to 165W TGP) Integrated graphics : AMD Radeon 680M |
| Memory | DDR5-4800MHz 32GB*2 |
| display | Main screen: 16 inches, 2560*1600 resolution, 165Hz refresh rate, secondary screen: 14.1 inches, 3840*1100 resolution, 60Hz |
| storage | 2TB+2TB M.2 NVMe SSD（PCI-E 4.0，RAID 0） |
| interface | USB 3.2 Gen 2 Type-A*2, USB 3.2 Gen 2 Type-C*2 (one of which supports power supply), HDMI 2.1*1, 3.5mm composite audio*1, microSD card reader*1 (UHS-II), RJ45 wired network port*1 |
| connect | Wireless: Wi-Fi 6E (802.11ax), Bluetooth 5.2 (dual-band 2*2) |
| operating system | Microsoft Windows 11 Home 64-Bit |
This test used two sets of platforms, namely the ROG Ice Blade 6 dual-screen gaming notebook equipped with the Ryzen 9 6900HX processor, and our first test platform of the Radeon RX 6400 at that time.
The CPU used the Ryzen 7 5700G for comparison with the previous generation. The performance of the nuclear display, the memory is DDR4-3600 16GB*2.
