AMD Radeon R9 M390 vs AMD Radeon R9 M390X vs AMD Radeon R9 M365X

AMD Radeon R9 M390

The AMD Radeon R9 M390 is a mobile graphics card from 2015 and positioned as a fast mid-range GPU. It should be based on the the old Pitcairn chip (e.g. in 2012 used in the desktop 7870 graphics card) and offers 1024 shader cores clocked at 958 MHz. Furthermore, 2 GB GDDR5 dedicated graphics memory are connected via a 256 Bit memory bus. The graphics card is used in the Apple iMac 27-inch late 2015 (mid range model).

The performance of the Radeon R9 M390 slightly above a Nvidia GeForce GTX 960M or 870M but still beyond a desktop Radeon R7 370. Therefore, demanding games of 2015 may only run in medium settings at up to full HD resolutions fluently. The native 5K resolution of the iMac or even the perfectly scaled 2560x1600 will be definitely too much.

AMD Radeon R9 M390X

The AMD Radeon R9 M390X is a mobile high-end graphics card for laptops. It is most likely based on the same chip as the AMD Radeon R9 M295X in the iMac 5K Late 2014. That means it should be based on the third generation of GCN (desktop Tonga chip). The amount of shader cores is identical but the core clock is reduced by 15% (from 850 MHz to 723 MHz) and the memory is also clocked slower (5448 MHz vs 5000 MHz).

The performance should be a bit below the M295X. Compared to the competition, the R9-M390X should be positioned somewhere between the GeForce GTX 965M and 970M and therefore suitable for high-end games in 1080p resolution and high detail settings.

The card was first mentioned by Alienware on their twitter account and should feature 4GB VRAM according to the tweet.

The power consumption should be rated around 100 Watt TDP and therefore suited only for large and bulky laptops (like the Alienware M17x it was announced in).

AMD Radeon R9 M365X

The AMD Radeon R9 M365X is a mid range DirectX 12 compatible graphics card for laptops. It is based on the GCN architecture and manufactured in 28nm. The older Radeon R9 M270 and the current Radeon R9 M370X are very similar (see for gaming benchmarks).

The R9 M365X uses 640 shader cores (10 compute units) clocked at 925 MHz (max.) and supports according to the AMD website 4 GB GDDR5 at 1125 MHz (4 GHz effective). The only used version in a Toshiba laptop so far however only uses 2 GB GDDR5.