Laptops with AMD graphics may be few and far between, but that’s partially because AMD simply hasn’t had many current-generation GPUs to offer laptop vendors. Until recently, it was basically the entry-level Radeon RX 7600M family or the top-end Radeon RX 7900M—essentially a Radeon RX 7900 GRE in mobile form.
Now, the company has quietly listed the Radeon RX 7800M on its product specifications section in its website. The new notebook GPU is rather similar to the desktop form of the Radeon RX 7800 XT, just with a cut to the clock rate, to the memory controller, and to the power limit.
The slashed memory bus width and infinity cache are going to have the greatest effect on game performance. Where the desktop Radeon RX 7800 XT has a 256-bit memory bus with four Memory and Cache Dice (MCDs), the mobile version loses one, giving it a 192-bit memory bus and 48MB of Infinity Cache. This will hurt performance primarily in games running at high resolutions.
However, in terms of compute resources, the new mobile chip is nearly identical to the desktop board, with just a small cut to clock rate differentiating the two. In practice, we expect that it will actually run considerably lower clocks in light of the much-reduced power limit. In fact, we wouldn’t be surprised if this part runs very similarly to the Radeon RX 7900M that shares the same power limit.
Coincidentally (or not?), 30 WGPs happens to be the same core configuration found in the just-announced PlayStation 5 Pro from Sony. The PS5 Pro enjoys considerably more memory bandwidth than is available to the Radeon RX 7800M, but it also has to share that RAM with the eight Zen 2 CPU cores on its die. It also likely benefits from various architectural enhancements, as its GPU is said to be closer to RDNA 4 than RDNA 3.
We do actually have some preliminary performance figures for the Radeon RX 7800M, in fact. However, this data comes from One-Netbook, who is selling an eGPU dock for its OneXPlayer handhelds that includes a Radeon RX 7800M. So saying, the data is based on an eGPU dock and not a GPU built into a laptop.
Still, running the numbers, it looks like the Radeon RX 7800M will come in well ahead of the GeForce RTX 4070 Laptop model, and surprisingly, a fair bit behind the higher-end Radeon RX 7900M. Of course, that is a much larger GPU. Naturally, NVIDIA’s bigger chips, the GeForce RTX 4080 Laptop and GeForce RTX 4090 Laptop, will run rings around the RX 7800M, but NVIDIA also has a fabrication process advantage at play here.
Hopefully laptop vendors actually put the Radeon RX 7800M in more than a half-dozen machines. Portable PCs with AMD’s discrete GPUs inside have been very difficult to find in the last couple of years. Of course, the company is likely to launch RDNA 4 discrete GPUs before long, but it may be a while before those show up in laptops.