TechPowerUp not too long ago examined AMD’s new Radeon RX 6400 GPU on the slower PCIe 3.0 interface to measure any substantial drops in efficiency in comparison with PCIe 4.0 and located that to be the case because of the GPU’s unorthodox configuration of simply 4 PCIe lanes. On common, efficiency drop-offs had been upwards of 14%, relying on the decision.
AMD’s Radeon RX 6400 is the corporate’s latest entry-level GPU for the desktop market that includes AMD’s tremendous tiny Navi 24 die, initially for laptops. Like its greater brother, the Radeon RX 6500 XT, this GPU solely packs 4 PCIe 4.0 lanes as a measure to chop down prices. The Radeon RX 6400 includes a tough 13% discount in core rely and reminiscence bandwidth in comparison with the Radeon RX 6500 XT. The graphics card has simply 768 cores and 128 GBps of reminiscence bandwidth, because of a discount in GDDR6 speeds to 16 Gbps. Nevertheless, reminiscence capability stays the identical at 4GB. However the Radeon RX 6400’s fundamental power is its energy consumption. It has half the Radeon RX 6500 XT energy draw for 53W, making this GPU very helpful in small techniques finances techniques that can’t energy higher-end GPUs with auxiliary energy.
Within the 24 video games, TechPowerUp examined, the Radeon RX 6400 operating on PCIe 3.0 averaged a 14% lower in efficiency at each 1080P and 1440P cumulatively in comparison with PCIe 4.0. 4K outcomes had been even worse, with a 23% deficit in efficiency. Nevertheless, we doubt it’s going to matter a lot because the Radeon RX 6400 provides unplayable FPS on both PCIe era.
A few of the worst offenders included F1 2021 and Doom Everlasting, which noticed a 79% and 43% distinction in efficiency at 1080P. Fortunately, virtually all different titles examined had been within the 14% vary or decrease, however these two video games particularly present how really PCIe bandwidth-intensive some recreation engines can grow to be.
TechPowerUp’s testing for the Radeon RX 6500 XT confirmed practically the identical outcomes, displaying a 13% deficit in efficiency for PCIe 3.0 vs. PCIe 4.0. The Radeon RX 6400 cannot escape Navi 24’s four-lane limitations, even when the GPU itself is slower. The Radeon RX 6400’s PCIe 3.0 was virtually 20% slower than GeForce GTX 1650, which operates on the identical PCIe 3.0 interface and runs on a a lot more healthy x16 lane configuration. Nevertheless, when put in on a PCIe 4.0 interface, the Radeon RX 6400 carried out equally to the GeForce GTX 1650.
Customers eyeing the Radeon RX 6400 want a PCIe 4.0 platform to keep away from the extreme efficiency drop-off from PCIe 3.0. The most important challenge is that almost all techniques are nonetheless on PCIe 3.0, and the shoppers which might be possible to purchase a Radeon RX 6400 are on an previous system. If you do not have entry to PCIe 4.0, the higher different is Nvidia’s GeForce GTX 1650 and even the extra senior Radeon RX 570, which is quicker than the Radeon RX 6400 and does not require PCIe 4.0 to unlock its full efficiency.