Recently we examined how PCI Express bandwidth influences the performance of the 8 GB Radeon RX 9060 XT when local video memory (VRAM) is exceeded. The entire purpose of that testing was to push past the VRAM limit, which, unfortunately for 8 GB graphics cards, is a relatively easy task in 2025. This can happen even when using settings that would otherwise be highly playable, as demonstrated by the 16 GB model.
This is an interesting test for several reasons, the most notable being that PCIe bandwidth becomes a primary bottleneck when required VRAM is exceeded. Increasing bandwidth can help reduce the performance penalty of moving game assets into local system memory (RAM).
Understanding VRAM and PCIe Bandwidth
To briefly explain, when VRAM runs out, game assets are shifted to system RAM. The data must pass through the PCI Express bus to the CPU's memory controller and then out to RAM, where it can be stored.
The reason why this is often catastrophic for performance is bandwidth. In the case of the GeForce RTX 5060 Ti, the VRAM has a peak bandwidth of 448 GB/s, which is quite a lot. In contrast, the theoretical peak bandwidth for system memory is much lower – around 96 GB/s for dual-channel DDR5-6000 and approximately 50 GB/s for dual-channel DDR4-3600, depending on several factors.
RTX 5060 RTX 5060 Ti RTX 5070 RTX 5070 Ti RTX 5080 Price MSRP $300 $380 / $430 $550 $750 $1,000 Release Date May 2025 April 2025 Mar 2025 Feb 2025 Jan 2025 Process TSMC 4N Die Size (mm²) 181 mm² 263 mm² 378 mm² Core Config 3840 : 120 : 48 4608 : 144 : 48 6144 : 192 : 80 8960 : 280 : 96 10752 : 336 : 112 L2 Cache (MB) 32 MB 48 MB 64 MB GPU Boost Clock 2497 MHz 2572 MHz 2512 MHz 2452 MHz 2617 MHz Memory Capacity 8 GB 8 GB / 16 GB 16 GB Memory Speed 28 Gbps 30 Gbps Memory Type GDDR7 Bus Type / Bandwidth 128-bit, 448 GB/s 192-bit, 672 GB/s 256-bit, 896 GB/s 256-bit, 960 GB/s PCIe Bus Interface PCIe 5.0 x8 PCIe 5.0 x16 Total Board Power 145 W 180 W 250 W 300 W 360 W
The key takeaway is that 50 to 96 GB/s is considerably less than 448 GB/s, and this doesn't even account for increased latency. These figures also ignore the PCIe interface as a potential bottleneck, which can further reduce effective bandwidth depending on the setup.
PCI Express 5.0, for example, provides a bi-directional bandwidth of 128 GB/s with all 16 lanes available. That drops to 64 GB/s for PCIe 4.0 and 32 GB/s for PCIe 3.0. However, the RTX 5060 Ti is limited to just 8 lanes, so these figures are halved again: 64 GB/s for PCIe 5.0, 32 GB/s for PCIe 4.0, and only 16 GB/s for PCIe 3.0.
This means that when the 8 GB VRAM limit is exceeded, performance could be significantly better on PCIe 5.0 compared to 4.0 or 3.0. And that's exactly what we explore in this review.
For testing the RTX 5060 GPUs, we will focus on upscaled 1440p – so not native 1440p, but also not 1080p. As we've demonstrated in the past, it's very easy to overwhelm 8 GB GPUs at 1080p in modern games using settings that are still very playable on a 16 GB model. Furthermore, these 8 GB GPUs were not 'intended' or 'designed' specifically for 1080p gaming. That claim is simply untrue and not reflected in how these products have been marketed.
... continue reading